Finishing of carpentry and building products.
Construction Production of window blocks with separate sashes.
For the production of elements of window blocks, it is planned to use lines for cutting lumber, processing bars, cleaning surfaces and processing the perimeter of the edges of window sashes.
The OK507 line is designed for cutting unedged lumber into blanks for sash bars of window blocks. A receiving roller conveyor transports the stack of lumber to an inclined elevator, which rotates at an angle of 45°. From above, the boards alternately descend onto the conveyor chains, and then onto the roller conveyor, and after releasing a number of boards under the slope of the elevator, the gaskets slide onto a belt conveyor, which feeds them into the drive. A double-chain inclined conveyor carries the gaskets from the storage tank to a special conveyor. The board, placed on a roller conveyor, is transferred to a circular saw, on which preliminary cross-cutting is carried out with cutting out defects. When cutting, it is necessary first of all to obtain the longest blanks, since short ones are obtained along the way.
The section of board obtained after cutting is dumped onto a transverse belt conveyor, from where it arrives at the receiving table of the machine. The bars obtained as a result of cutting fall onto a transport device, from which the sash bars are selected by workers for trimming on machines, and unmeasured bars and waste (slats) are fed to a unit for dividing the waste into segments.
The line can process boards up to 6,500 mm long, 60–400 mm wide, 50–63 mm thick, and workpieces 310–2140 mm long, 47–70 mm wide, and 50–63 mm thick. Line productivity 21 m/min.
During the manufacturing process of window parts, the moisture content of lumber is systematically checked with a small-sized electronic moisture meter EVA-5M (Fig. 107).
After cutting, the workpieces are subjected to profile processing by milling on the OK508 line (Fig. 108). This line can process bars with a length of 380–2220 mm, a width of 40–42 mm, and a thickness of 38–61 mm.
The line productivity is 900 pcs/h with bar lengths up to 1.4 m and 450 pcs/h for bars longer than 1.4 m.
The cutting of tenons from the bars and the assembly of the sashes are carried out on the OK509 line, which includes two tenon-cutting machines, an assembly, slotting and glue-applying machine, a lifting table, etc.
The assembled sashes along the outer perimeter are processed on the OK511-2 line, consisting of machines for processing longitudinal and transverse edges. The line can process sashes with a length of 695–2310 mm, a width of 342–1280 mm, and a thickness of 38–61 mm. Line productivity is 135 sashes per hour.
At those enterprises where there are no lines, lumber is cut along the length to a given size on TsPA-40 circular saws, and in width - on TsDKA-3 circular saws. When cutting crosswise, an allowance is added to the specified size for further trimming.
The bar parts are processed as follows: the layers and edges of the warped bars are jointed on a planer; window frame parts are milled on a four-sided longitudinal milling machine.
Knots are sealed after processing the parts, taking into account the fact that after milling the defective areas are better visible. At some enterprises, knots are sealed before processing - as a result, the part is cleaner, since the plugs are cleaned during the processing of parts on a longitudinal milling machine.
Rice. 107. Small-sized electronic moisture meter EVA-5M: 1 – electronic measuring device; 2 – three-needle transducer
Rice. 108. OK508 line diagram for profiling of sash bars: 1 – line control panel; 2 – jointing and milling machine; 3 – feeder
Horizontal sash bars are usually prepared in multiples of length or obtained after processing rejected vertical sash bars.
If the enterprise has a four-sided longitudinal milling machine with five knife shafts, the bars for binding bindings, ebbs and covers can be made in multiple sizes in width in order to process two bars on the machine at a time and, installing a planing saw on the fifth horizontal shaft, cut them.
Flashings, flashings and glass layouts are cut to size on a “miter” on a circular saw or on special machine for insertion. To avoid the formation of chips or cracks in the flashings (when fastened with screws), it is necessary to select countersink holes in advance, and the diameter of the holes should be less than the diameter of the screw by the amount of the thread.
Rice. 109. A device for simultaneously drilling two holes for dowels: 1 – frame frame; 2 – trolley; 3, 4 – brackets; 5 – guide glasses; 6 – lever; 7 – electric drilling machines; 8 – support cross-beam; 9 – rod; 10 – channel
Lumber is cut into bars for window frames on line or on positioning machines, after which they are processed there. Processed bars of sashes, vents and frames undergo selective control and arrive at a buffer warehouse, where they are fully equipped according to size and purpose. Window sashes, vents, transoms, boxes are assembled in assembly machines (hires) using glue, installing wooden or metal pins made of soft metal in the corners of the joints flush with the plane. Holes for dowels are selected using an electric drill or a special attachment (Fig. 109) in two to four corners of the sashes at once. The device consists of a metal frame installed on a machine for assembling the sashes. Channels are attached to the frame posts, along which the trolley with the brackets located on it moves. A lever is hinged to the brackets, with the help of which the cart moves back and forth. Guide cups are attached to the brackets, through which the curtains pass, hingedly connected to the lever. On the rods there is a traverse with electric drilling machines attached to it. Depending on the distance between the holes being drilled, electric drills can move along a traverse. The operator (worker) uses a lever to set the electric drills to the required position above the sash, then lowers the lever, and the working electric drills select holes.
After this, glue dowels are installed in sashes, transoms, vents, boxes and placed on the underfloor area for the curing time necessary for the glue to set.
Before hanging the box, the transoms and sashes are processed around the perimeter to obtain the correct geometric dimensions. At the same time, the sashes and transoms are folded to form the quarters necessary for the vestibule.
To assemble sashes up to 1925 mm long, up to 740 mm wide and up to 60 mm thick, a VGO-2 hydraulic assembly machine is used, on which they are assembled.
Doors and window frames up to 2360 mm long, up to 1610 mm wide and up to 180 mm thick are assembled on a VGK-2 assembly machine.
The assembly of transoms and vents up to 460 mm long, up to 1290 mm wide and up to 55 mm thick is carried out on a VGF machine.
For assembling window sashes large sizes a VGS machine is used, on which it is possible to assemble sashes up to 2115 mm in length, up to 1660 mm in width, and up to 55 mm in thickness.
In addition, window and door frames can be assembled on a VGK-3 machine, where boxes up to 2755 mm long, up to 2966 mm wide, and up to 174 mm thick are assembled.
Template for folding window frames (Fig. 110, A) is a wooden frame assembled from milled bars. The position of the valves in the template is fixed by stops, and the stable position is fixed by clamps.
Template for processing door panels on both sides (Fig. 110, b) is also a frame assembled from bars with an adhesive tenon joint.
Template for processing window sashes and vents (Fig. 110, V) consists of a frame fastened at the corners with metal squares for greater strength. The position of the sash in the template is fixed with stops. The sash and vents are attached to the template using a clamp. The perimeter processing in this template is done on a milling machine.
Rice. 110. Templates: A– for folding window frames; b– for processing around the perimeter of door panels on both sides; V– for processing window sashes and vents around the perimeter (right and left sashes are placed in the template); 1 – template stiffening square; 2 – axis of rotation of the clamp; 3 – clamp; 4 – stops; 5 - frame
During processing, a profile is created that is mirror-like to the profile of the sash bars and sash, so when put in place, the window exactly fits the profile of the sash bars and sash; no additional work is required to fit the window to the sash. Sags from the planes of sashes and vents are removed using a wide thickness planer or three-cylinder grinding machine.
The groove for the casting is selected on a milling machine, ensuring the cleanliness of the processing. To install hinges in the sashes and bars of boxes on a machine with a vibrating head, sockets are selected rectangular shape. The dimensions of the sockets must correspond to the dimensions of the loops.
The vents in the sashes are hung on the work table after processing around the perimeter and selecting nests for the hinges. The ebb is not installed on the window, since in the lower bar of the window the ebb is integral with the bar.
The flashing and flashings in the outer and inner sash are installed at the workplace before or after hanging the window into the sash. The mortise ebb is installed with highly water-resistant glue and secured with screws or studs; the flashing covering the gap formed by the sash narthex is attached to the sash with glue and screws.
Production of window blocks with paired sashes. Window blocks with paired sashes are made mainly from specification lumber. The technological process stipulates that sawn timber is cut on a semi-automatic line OK507. In the absence of a line, lumber is cut lengthwise on circular saws for cross cutting TsPA-40, and widthwise on circular saws with caterpillar feed TsDK4-3.
For the production of parts and window blocks, it is recommended to use waste lumber, splicing them lengthwise into toothed joints. Parts can also be glued in width and thickness using a cold method in assembly machines or on a semi-automatic line. The surfaces to be glued are pre-milled. The blanks are glued together along the surface using DV504 lines.
The glued bars of boxes are subjected to profile processing on the OK503 line, consisting of a feeder, a jointing machine, a lath separator, and a four-sided longitudinal milling machine. It can process bars with a length of 750–2210 mm, a width of 54–143 mm and a thickness of 44–74 mm; line productivity – 460 pcs/h.
Profiling of sash bars is carried out on the OK508 line, cutting of tenons in the frame bars, processing of nests - on the OK505 line, and cutting of tenons and eyes in the sash bars and their assembly on the OK509 line. On one tenon-cutting machine the lugs are cut into the bars, on the other - tenons. After cutting, glue is applied to the tenons with a glue-applying device, after which the sashes enter the assembly machine. On a slotting machine, sockets for the middle bars are selected in vertical bars. The assembled sashes are collected into a stack on a lifting table, and in a mechanized warehouse they are kept until the glue has completely set. The line can produce products with a length of 690–2150 mm, a width of 300–1300 mm, and a thickness of 43–55 mm; line productivity 125 pcs/h.
In those enterprises where there is no line, window sashes are assembled in assembly machines. During the process of assembling bindings on machines, you need to ensure that the sashes do not have distortions, and that there are no leaks in the mates. The assembly accuracy is checked with a template from corner to corner.
Then the assembled sashes are processed along the outer perimeter (contour) on an OK213R2.02 unit, consisting of two machines for longitudinal and transverse processing of edges. The edges are processed with milling heads. Each machine has basing units, clamps for fixing the sashes and two movable supports. In addition, a mechanism for moving the sashes is mounted on the machine for longitudinal processing.
The units are adjusted to the size of the sash being processed according to a given program, which significantly reduces the setup time of the machines. The machine tools of the unit are covered with noise-absorbing cabins. The unit can process sashes with a length of 345–1,395 mm, a width of 295–1070 mm, and a thickness of 32–42 mm.
Electric motor power – 44 kW; productivity – 180 sashes per hour.
After processing the sash along the outer perimeter on a three-cylinder grinding or wide-bore thicknesser, the outer planes of the sash are cleaned and ground, after which it is placed in a template and the upper horizontal bar and two vertical ones are processed on a milling machine along the perimeter on three sides.
After processing along the perimeter, in the internal sashes, sockets for mortise hinges are selected, and in the outer and inner sash - sockets for mortise screws and holes for handle-screws, in the frame bars (impost) - a groove for a locking strip, and in sashes and vents - sockets for a screw screed
To chisel nests, install hinges and locks (screw handles) in them and secure them with pins, use the OK213R2.10 unit. Slotting heads are located on it to select nests, and high-performance automated units are installed to install devices (hinges, locks). All work on processing nests and installing devices is carried out automatically.
To adjust to the desired width of the processed sash, the unit is equipped with a programming device. The feed speed is stepless. The unit can process sashes with a length of 365–1395 mm, a width of 310–1070 mm, and a thickness of 42–52 mm. The feed speed of the rod conveyor is 6–30 m/min, the feed speed of the heads for selecting nests is 0.3–0.7 m/min. The unit is equipped with four slotting heads, two drilling heads and four heads for installing devices. The unit is serviced by two workers.
At enterprises where there are no lines, box blanks are processed as follows: bars that are warped and uneven are processed on a jointing machine, and then on four sides with profile selection - on a four-sided longitudinal milling machine.
In the horizontal bars of boxes for two- and three-leaf bindings, on a centrifugal or horizontal drilling and mortising machine, sockets for the tenons of the vertical impost are selected, as well as grooves in the impost for installing the lock wrapping strip. Tenons and eyes are cut on tenon cutting machines.
Sockets for hinges are selected in the vertical bars of the box, after which half hinges are placed at the workplace. Any defects (knots) in the bars are repaired on a machine. Grooves are cut in the lower horizontal bar of the box to drain water.
Window boxes are assembled in assembly machines VGK-2, VGK-3. When assembling boxes using glue, the tenon joint is secured with dowels installed on the glue. Pins are placed in all corners of the box, as well as in the places where the impost is connected to horizontal bars, flush with the plane of the box.
When assembling the box, you need to make sure that there are no distortions from corner to corner; The correct assembly is checked with a ruler and a template. The tenon joints of the boxes must be tight, without gaps.
When assembling a window block, the sashes and vents are hung on hinges in the frame, the sashes are adjusted to the frame, eliminating defects and inaccuracies. After assembly, the window block is painted and then glazed.
Specifications for the production of window blocks. Elements of window blocks must have the correct geometric shape.
On the front surfaces and at the ends of the connections of sashes, transoms, vents, valves and blinds, sagging is unacceptable.
It is forbidden to use wood of different species in a sash, frame, etc. The sealing of defects and processing defects with plugs and strips must be done with glue, and the plugs and strips must be free of defects, of the same type as the part and installed tightly without gaps, flush with the surface.
On the front surfaces of parts of windows and balcony doors under a transparent finishing coating, defects and defects in wood processing are not allowed.
Opaque coating should be done with oil or synthetic paints and enamels.
2. Manufacturing of door blocks
The technological process of manufacturing door blocks with panel panels consists of the following main operations: manufacturing frames and filler, preparing facing material, gluing door panels, processing panels around the perimeter, installing facings and layouts, manufacturing door frame, installation (fitting) of doors into a frame with hanging on hinges.
Door panels are made by filling a pre-assembled frame with slats, honeycombs assembled from lengths of solid fiberboard, plywood, paper honeycombs or broken strips of solid fiberboard.
For doors with a thickness of 40 mm, the frames are made from bars with a cross-section of 40–60×32 mm, which are cut to length from lumber 40 mm thick, with a moisture content of 9 ± 3% on a circular saw for cross cutting, and along the width - on a circular saw for longitudinal cutting. They are connected with a tenon or with metal clips end to end. Connecting the bars with tenons increases the strength of the frame, but increases the consumption of wood and the complexity of manufacturing the frame due to the introduction of an unnecessary operation (cutting the tenons). The staples are placed so that the frame does not unravel while filling it with the center and placing it in the press.
To make a glazed door, two frames are used: external and internal. The sections of the bars of the inner frame must be the same as the sections of the bars of the outer frame. The resulting blanks are processed to size in thickness on thicknesser or four-sided longitudinal milling machines. The frame bars should not have rot, curvature, falling out, decayed, rotten or tobacco knots.
The filler is made from small-sized lumber and production waste (for solid and sparse cores), waste plywood and solid fiberboard 4 mm thick (for honeycomb filling).
The moisture content of waste wood obtained from cutting lumber for joinery is approximately 15%.
Before filling the center, they must be dried to a moisture content of 9–10% in drying chambers.
For rooms with a relative air humidity of more than 60%, doors are made with solid filling wooden slats. After assembling the frame, plywood or hard fiberboard, previously coated with glue, is placed on it and attached to the frame with small nails 20–25 mm long. In doors with solid filling, a thickness of 3 mm of solid fibreboard cladding is allowed.
After fixing the cladding, the frame is turned and the entire internal space is filled with slats of a thickness corresponding to the thickness of the frame. When laying the slats, you must ensure that they are pressed tightly against one another, their surface is smooth, and the joints are spaced apart.
After filling with slats, the frame is closed on top with a second facing sheet, pre-smeared with glue, and attached with small nails on four sides. When making a shield with sparse filling, the frame is filled not completely, but at intervals.
The door panel with honeycomb filling consists of a frame with honeycomb gratings placed in it. The honeycomb is assembled from strips of plywood or hard fibreboard, 4 mm thick and 32 mm wide.
In the strips, grooves are cut through 40 mm with a width equal to the thickness of the strips plus 1 mm, and a depth equal to half the width of the strips plus 1 mm. A honeycomb-shaped lattice with cells measuring 40×40 mm is assembled from strips with slots. The shield frame is filled with two or three honeycombs.
To internal doors facing material glued with urea glue, and to the external ones with KB-3 glue (waterproof).
When the annual production volume of doors is small, mechanical presses are used for gluing. Gluing panels in mechanical presses consists of the following operations: forming the door panel, forming packages and pressing them in, holding the package under pressure for the glue to set, curing the door panels (acclimatization).
Door panels are formed as follows: a pre-assembled frame is placed on a work table located near the press, and a cut sheet of plywood or hard fiberboard with glue pre-applied to one plane is placed on it. The glue is evenly distributed over the entire plane of the sheet; the layer should not be thick, otherwise excess glue will be squeezed out under pressure in the press, which will make it difficult to disassemble the bags. The facing sheet is placed with the coated side on the frame. Its ends should extend beyond the frame evenly on all four sides. The laid sheet is secured in the corners with small nails or pins, then the frame is turned over and the middle of the shield is filled with bars, honeycombs, etc. Two bars with a cross section of 32?50–70?400(700) mm are placed close to the middle of the longitudinal bars, and bars 400 mm long are placed for doors with a height of 2000 mm, and with a length of 700 mm - for doors with a height of 2300 mm so that a lock can be inserted into the door regardless of whether it is hinged on the right or left, and a handle can be installed.
The honeycomb filling should fill the entire internal space of the frame, and the ends of the strips of one honeycomb should freely fit into the free space between the ends of the strips of other honeycombs.
After filling the middle of the shield, the frame is covered with another facing sheet, pre-lubricated with glue, and secured in the corners with small nails. Then the assembled shield is removed from the work table and transferred to the press. 18–20 panels 40 mm thick are placed in the press. The panels must be laid strictly one above the other, without displacement; on top they are covered with a massive three-layer wooden shield, similar to the base. Then the drive mechanism of the press is turned on and the package is compressed. After gluing the boards, i.e. after 6–12 hours, the finished package is disassembled, the boards are stacked for free exposure for 12–24 hours in a room with normal humidity (up to 60%) and a temperature of 18–20 °C. In a hot hydraulic press, the panels are glued together in the same sequence as in a mechanical one, but they are formed on a metal pallet.
The gluing pressure should be 0.5–0.8 MPa, the lower limit applies to panels with honeycomb and sparse filling, and the higher limit – with continuous filling.
After gluing and curing, the boards are processed around the perimeter, and then facings and layouts are installed. Perimeter processing includes filing the board to the required size and grinding the surfaces of the board. In glazed doors, glass layouts are installed.
They make a box and drive the canvas into it in the same way as in paneled (frame) doors.
The line for the production of door panels consists of a number of sequentially arranged mechanisms. A facing sheet of hard fibreboard 4 mm thick, coated with glue on the mesh side, is placed on the conveyor belt. Two vertical bars of the frame and bars under the lock are placed on this sheet, after which the resulting package is transferred to the next position, where two transverse bars of the frame are placed on it, which are secured at the corners with paper clips. Then the middle is filled with either bars (for doors with solid filling) or honeycombs.
At the next position, the bag is covered with a sheet of fibreboard, on the mesh side of which glue is first applied. In the corners, the sheet is baited with small nails. The assembled door package is fed into the loading shelf by a chain conveyor. After loading all 15 floors of the shelf with the feed mechanism, the bundles of canvases are fed into the P-797-6 press. Bonding is carried out using urea adhesives (KF-Zh) for 6–8 minutes at a press plate temperature of 115–120 °C. After gluing, the press opens and the loading mechanism is turned on, which loads the next batch of canvases from the shelf into the press and at the same time partially pushes the glued canvases onto the unloading shelf. To completely push the webs out of the press into the unloading shelf, the unloading mechanism is turned on, which pushes each web into the unloading shelf, and from there it is transferred to the lifting storage table, from where the webs are transferred to a non-driven floor conveyor. The fabrics are kept on this conveyor for 24 hours to equalize stress.
Processing of door panels around the perimeter occurs as follows: a stack of glued door panels, after curing, is supplied to a hydraulic lift with an automatic loader, from where each panel is fed in turn to a format finishing machine, on which the longitudinal edges are processed first, and then the transverse ones; At the same time, the necessary bevel is formed on the edges using cutters. When leaving the machine, the door leaves are covered with drying oil on all sides. special device. After sanding, the web is fed through a roller conveyor to a machine where slots for half-loops are selected. Then each door leaf is fed to a lifting storage table, where a stack of door leaves is formed. As stacks of the required height are formed, they are fed by a double-chain floor conveyor to the dispensing mechanism, from which each blade is fed to the first drilling machine for sampling in the longitudinal edge of the socket for the lock or latch body. On the second drilling machine, a socket is selected for the lock bar and a hole for the lock handle. The processed webs are transported via a roller conveyor for installation in boxes.
The door block assembly flow consists of two lines: I– assembly and transportation of boxes, II– assembly and transportation of blocks.
On line I the work is carried out as follows. The box bars, made in the woodworking shop, are transported on a trolley to a two-saw machine, on which nests for the hinges are cut. At the workplace, the worker drives a half-loop into the slot and secures it with pins or screws, after which the bars with spikes, lubricated with glue, are assembled into a box in an assembly machine. The boxes assembled with glue and dowels are delivered to a double-chain storage conveyor, where the glue naturally hardens. As needed, boxes are transferred from this conveyor to the block assembly line.
Line II located at right angles to the line I and consists of a single-chain floor conveyor that moves the door leaves in a vertical position. Workplaces are located along the conveyor. At the first two, half-loops are screwed onto the canvas, at the third workplace the screws are finally screwed in with a screwdriver, at the fourth, the canvas is hung (driven) into the box. The worker engaged in tightening the screws controls the pedal stops, with the help of which the door is installed in the right place to perform work operations.
Technical specifications for the manufacture of doors. Doors are manufactured in accordance with GOST standards and working drawings. Deviations from the nominal dimensions of door blocks and assembly units (leaves, frames) must comply with existing regulatory documents.
On the front surfaces of canvases and boxes, sag of parts that do not have chamfers at the mating points is not allowed. Doors with increased moisture resistance are made from coniferous wood: pine, spruce, fir, larch and cedar. It is not allowed to use wood of different species in the door leaf or frame, with the exception of pine, spruce, fir and cedar (for opaque finishes).
Doors are mainly made with opaque coatings. Doors made of hard deciduous, coniferous and valuable wood selected for quality, color and texture are finished with a transparent coating.
Devices of the same type and purpose are installed in the doors at the same level. Doors and windows are transported in containers (Fig. 111).
Rice. 111. Container for transporting window and door units: 1 – frame; 2 – stand; 3 – retractable rod; 4 – pressure beam; 5 – clamping screw; 6 – rubberized tape
When storing and transporting joinery products, they should be protected from mechanical damage, contamination, moisture and direct sunlight.
3. Manufacturing of carpentry partitions and vestibules
Carpentry partitions are made in the form of panels using a technology similar to the technology for manufacturing frame doors.
Panels for carpentry partitions are made in widths of 600, 1200 mm, heights of 2300 mm or more, and thicknesses of 54, 64, 74 mm. The panels arrive at the construction site assembled with panels and bindings.
In carpentry partitions, single blind (non-openable) sashes and transoms are installed, which serve to illuminate one room from the light openings (windows) of another.
The panel is installed in the grooves of the strapping bars. If operating conditions require a soundproof partition, then a thicker frame is made, and the panel is glued together from hard wood-fiber boards, laying a soft wood-fiber or mineral wool board between them.
Partitions are also assembled from profile boards 27–35 mm thick, 64–140 mm wide, quarter or tongue and groove. The boards are manufactured at factories and delivered to the construction site either in strips or in cut form.
The vestibule represents wooden frame, to which the fence panels are attached. Depending on the loads, the vestibule frame is made of bars with a cross section of 44–54? 74–94 mm.
The bars are supplied to construction as moldings with a moisture content of up to 18%, and during construction they are cut into place. The vestibule panels are frames lined on both sides with plywood of increased water resistance or super-hard fibreboard 6 or 8 mm thick with solid filling in the middle with wooden slats. The height and width of the shields depend on the size of the vestibule; the thickness must be at least 40 mm.
Shields are made according to technological process, similar to the production process of panel doors.
For vestibules in public unique buildings, panels are used, lined with veneer made from valuable wood or trimmed with paper that imitates the texture of valuable wood.
4. Manufacturing of built-in furniture
Built-in wardrobes and mezzanines consist of door and mezzanine blocks, side and intermediate walls, plinths, platbands, and mounting beams.
Door and mezzanine (panel) blocks are manufactured using a technological process similar to the production of panel doors.
The door leaf of the cabinet, mezzanine is covered in groove and tongue with wooden coverings, PVC profile or lined with edge plastic. The covers are attached with glue.
When making cabinet doors from chipboard, the latter is cut on circular saws, after which a groove is selected on the edges on a milling machine for attaching the facings. The covers are secured in assembly machines or clamps. After waiting for the glue to set, the surfaces of the door panels are ground on a three-cylinder grinding machine. Doors can be covered with valuable wood veneer or pasted over polyvinyl chloride film, the side shield wall is made of particle board and lined with veneer made of valuable wood or covered with polyvinyl chloride film.
The intermediate wall is made of two solid fiberboards glued together with the mesh sides inward. After gluing, it is necessary to keep the slabs stacked in the workshop for 24 hours at a temperature of 18–20 °C and a relative air humidity of 60%, after which they are filed around the perimeter, and then the edges are covered (before painting) with drying oil to avoid moisture. Adjustable shelves up to 800 mm long are made of plywood, and those longer than 800 mm are made of particle board, the outer edge of which is lined with wooden lining.
Slabs and plywood for shelves are cut on a circular saw, corners are cut out according to the markings or template on band saw. The surface of the shelves is ground on a grinding machine.
Cabinet elements finished with valuable wood are varnished, while unfinished ones are painted with nitro enamel or oil paint.
During transportation, to protect against damage, cabinet elements are packaged in pairs with their front surfaces facing each other, with paper placed between them. Cabinet elements are stored horizontally in dry warehouses and transported in containers or covered wagons.
For construction, cabinets are delivered complete with devices placed in separate containers.
5. Production of skirting boards, platbands, floor boards, handrails, cladding
Parts are manufactured using the following technological process: drying wood, cutting lumber to length and width on circular saws, sealing defects, followed by holding time necessary for the glue to set. Defects are repaired on a machine for drilling and sealing knots, processed on four sides (milled) to create a profile - on a four-sided longitudinal milling machine, cut to size - on a cross-cutting machine. Then the floor boards are antiseptic. Parts are supplied cut to a length of 2100 mm or more.
JOINERY AND INSTALLATION WORKS ON CONSTRUCTION
1. General information about installation and installation equipment
Installation of wooden structures is carried out in various ways: individual elements, parts or assembly units designs. The method of installing joinery depends on the size of the items being installed and the methods for lifting them.
When installing wooden structures, the entire process is divided into separate stages, consisting of preparatory work, assembly and installation of structures in the design position.
Preparatory work includes checking: the correct dimensions of the openings into which the structures are mounted; strength and stability of mounted wooden structures; working condition of tools and mechanisms for lifting, scaffolding, signaling.
Before installation, wooden structures should be carefully checked, and also checked whether everything has been done to protect them from moisture and fungal damage.
Places for slinging products are marked with paint. They check the accuracy of the assembly of structures, its compliance with working drawings, as well as any deviations allowed. It is necessary to carefully check the installation sites of the structures and eliminate any existing irregularities or deviations.
Installing structures in place involves slinging, lifting and installing them in the design position, aligning them and finally securing them.
Wooden structures are installed according to pre-approved technological maps, and if they are missing, according to an approved scheme.
Used for installation of wooden structures installation equipment– cranes, winches, blocks, hoists and various mounting devices – slings, traverses, grips. These machines and devices are also used for loading and unloading operations.
Cranes. In construction, slewing cranes are widely used, which are lifting and transport machines that can be used to lift, horizontally and inclinedly move loads, as well as rotate them around the vertical axis of the crane column (tower).
For installation building structures They use self-propelled jib cranes - pneumatic-wheeled, crawler-mounted, truck-mounted, etc. These cranes have great mobility; their installation and movement do not require rail tracks.
Winches. There are special and general purpose winches. Special winches are used in cranes to lift and lower loads (freight) and to change the position of the boom (boom). Based on the installation method, there are stationary and mobile winches. General purpose winches can be manually or mechanically driven (from an electric motor or from an internal combustion engine).
Manually driven winches are used for installation work with low speed movement of loads, as well as for pulling loads when lifting them. Mechanically driven winches are divided into gear, reversible and friction.
Steel ropes used for lifting, lowering and moving loads, making slings, cables, guy ropes. They are equipped with lifting mechanisms - cranes, winches, pulleys, hoists, etc.
Rice. 112. Slings for construction: a – single-branch 1SK; b – two-branch 2SK; c – three-branch 3SK; d – four-branch 4SK; d – ring SSCs; e – two-loop SCP; g – scheme of slinging with two SKK slings; h – diagram of cargo slinging with two SKP slings; 1 – split link; 2 – equalizer; 3 – equalizing thread; 4 – rope branch; 5 – capture
During operation, you need to constantly monitor the condition of the ropes.
Slings. For slinging construction cargo, floor panels, walls, beams, trusses, window and door blocks, cargo rope slings are used. Slings are produced (Fig. 112) with straight branches for lifting and transportation with mounting loops: single-branch - 1SK, two-branch - 2SK, three-branch - 3SK and four-branch - 4SK. In addition, there are ring slings without mounting loops - SKK and two-loop slings - SKP. The lifting capacity of slings with straight branches, ring and double-loop slings is 0.32–32 tons.
Rope branches of slings are made from a whole rope without splicing.
When slinging loads, you must select the correct sling and securely attach it to the load. The sling should not have sharp bends, loops or twists.
To grip structures that need to be slinged at two or more points, traverses are used, which are a regular beam made of pipes with hangers. Rigging devices in the form of traverses, slings, grips are attached to the working parts of lifting machines with rings, hooks, and loops.
2. Assembly of window and door units in construction
Most window and door units arrive at the construction site pre-assembled, with sashes, vents, transoms, and curtains hung on hinges. Only in in some cases During construction, window and balcony blocks are assembled from elements. In the design position, window and balcony blocks are usually installed in the form of ready-made blocks with hanging elements.
Assembly of window blocks. The work on assembling window blocks consists of adjusting and hanging the window into the sash (Fig. 113, A), fittings with folding of the sashes together and to the frame with the installation of flashings (beads) (Fig. 113, b), installation of half-hinges on the sashes and frame (Fig. 113, V), low tide installations (Fig. 113, G), hanging the sash in the frame (Fig. 113, d). After this, cut the devices (screws, handles-brackets). Before installation in the opening, window and balcony blocks are dry-dried and painted.
Elements of window units are assembled on site. After assembly, the block elements are left for 1–3 hours for the glue to set, and then the hinges, molding, flashing, etc. are installed. The nests for the hinges are marked using a Pavlikhin template. To form nests for mortise hinges, you can use a set of three chisels (Fig. 114). One mortise hinge card is hammered into the box block, and the other into the inner binding block. Unlike conventional hinges, mortise hinges are secured with studs.
The doors are hung on special tables.
Folding the sashes involves selecting the folds at the sashes that form the vestibule. Folding can be done with mechanized or hand tools. To add a narthex to windows without removing them from their hinges, use an additional planer (Fig. 115). When adjusting the sashes, carefully check the correctness of the rebate, i.e., the tightness of their fit to the quarters of the frame. In all vestibules, a gap of 2–4 mm is left between the sashes and the frame for subsequent coating of the sashes with a layer of paint and free opening and closing of the sashes.
Rice. 113. The sequence of assembling window blocks with separate sashes: a – fitting the window; b – adjustment of the sashes with installation of the cover; c – installation of half-loops; d – low tide installation; d – hanging the sashes in the frame, installing layouts on the glass; 1 – leaf; 2 – window; 3 – box
Rice. 114. Chisels for selecting sockets for mortise hinges: a – 44 mm wide; b – 30 mm wide; c – 32 mm wide; 1 – handle; 2 – blade
Rice. 115. Additional planer: 1 – knife; 2 – knife stop; 3 – fastening bolt; 4 – plane body; 5 – nut
Then the sashes are hung on the hinges, making sure that they open freely and smoothly, do not spring and are motionless in any position after opening.
The installation locations of the device are marked using templates. The simplest template is a thin board or plywood with cut-out contours of devices, along which markings are made with a pencil. You can mark places for placing devices by outlining the devices themselves along the contour with a pencil. Sockets for devices are selected with a chisel or chisel so that their depth along the entire contour of the device is the same. The devices are embedded flush with the surface of the wood. The permissible deviation should be no more than 0.5 mm. Window and door fixtures are attached to the products with countersunk screws. The dimensions of the screws must correspond to the dimensions of the holes in the devices. An approximate procedure for installing devices on windows and balcony doors is shown in Fig. 116.
Rice. 116. The procedure for installing devices in carpentry: a – window blocks OS18-18V; OR18-18V; b – window blocks OS12-1, OSP5, OS12-13.5; c – balcony doors BS28-9, BR28-9; d – window blocks OS18-13.5; OR18-13.5; 1, 3 – loops; 2 – transom device; 4 – emphasis; 5 – clamp; 6 – wrapping; 7 – screed.
To lock windows with paired sashes, use a mortise window tie ZR1 and a mortise tie ZR2. Typically, two wraps are placed on each sash at a distance that ensures uniform adhesion of the sash to the frame, and taking into account the possibility of opening the bindings from the floor without using a stand.
For window sashes up to 1100 mm high with paired or separate sashes, the ShN2 overhead latch is used, and for window sashes with a height of more than 1100 mm and balcony doors with paired or separate sashes or leaves, the ShN1 overhead latch is used. The overhead gate valve 3T is used for locking residential and residential window sashes. public buildings.
In windows with separate sashes for residential and public buildings, PC-type handles are used to open the sashes. These same handles can also be used on balcony doors. The window sashes are fixed with clamps (Fig. 117).
Rice. 117. FK1 type clamp (a) and its installation (b)
To lock one of the leaves of double-leaf balcony doors with separate leaves, ShV type latch bolts are used. Their moving parts should open smoothly, without much effort. Door (upper) bolts are installed at a height of 1.8–1.9 m so that they can be opened from the floor. To limit the opening of the sashes and prevent them from hitting the wall, a UO type window stop is installed on the inside of the outer sash of a block with separate sashes. For transoms of public buildings with paired and separate sashes up to 1300 mm wide, the PF1 transom device is used, and for transoms up to 830 mm wide, the PF2 device is used.
In products made of wood that causes corrosion (oak, etc.), screws with an anti-corrosion coating should be used.
Assembly of door blocks. The work on assembling door blocks consists of assembling the frame, selecting folds of the panels along the frame, fitting the door to the frame, inserting hinges, locks and other devices, installing flashings, hanging the panels, sanding and painting. The boxes are assembled in an assembly machine (vaima).
The single-leaf door leaf must be carefully adjusted to the frame quarters. When working manually, first adjust the edge of one vertical bar, the second and then the horizontal bar.
For double-leaf doors, the rebate is first selected along the trunk of the panels and, after adjusting the panels, they are folded in such a way that the horizontal bars (of the frame doors) coincide, i.e., are on the same level. Then both canvases are adjusted; they should fit snugly to the quarters of the box around the entire perimeter, without protruding beyond the plane of the box bar and without sinking. Hang the fabric on two or three loops, and the bouts of the upper and lower loops should be on the same vertical axis. Holes for locks in door leaves are selected using a jig (Fig. 118), and you can also select slots on hung door leaves. Select slots for door locks as follows. Open the door at approximately an angle of 75° and secure it in this position by installing two wedges under the lower part of the leaf. Then mark the installation location of the conductor. The conductor is installed according to the markings and secured to the door with screws.
Rice. 118. Jig for making holes for locks in doors: 1 – clamping pins; 2 – door; 3 – rack; 4 – nails
The position of the conductor can be fixed with a strip nailed to the edge of the canvas from above. The length of the rail should correspond to the position of the lock from the top of the door.
The holes in the door according to the jig are selected using an electric drill. First, select a hole for the handle, a hole and a groove for the key, then a groove for the lock.
To close entrance doors in apartments, as well as individual premises of public buildings, a mortise cylinder lock and a lock with a bolt ZV1 are used (Fig. 119, A).
Locks are inserted into vertical bars. When installing locks with handles, it is necessary that the axis of the handle coincides with the axis of the key. The lock strips and cylinders are cut flush with the surface of the strapping bars and boxes.
To close cabinets, locks are used (Fig. 119, b, c), and for opening blind and glazed room doors - a handle-bracket (Fig. 119, G). Attach the bracket to the door at a distance of 950–1000 mm from the floor. Handle-buttons are installed on the doors of bathtubs and toilets (Fig. 119, d). For doors that cannot be locked, simple latches and push-button handles are used. To protect against the penetration of kitchen odors into the rooms, mortise latches are installed in the kitchen doors.
Rice. 119. Devices for carpentry: a – cylinder mortise lock for doors with bolt ZV1; b, c – locks for cabinets; d – PC type handles; d – handle-button RK-2; 1 – locking bracket; 2 – latch handle
When installing painted window and door blocks into openings, chips and other defects appear on the surface, which are filled with putty and painted.
3. Installation of window and door units
When constructing large-block, brick and wooden log, block and frame buildings, window and door blocks are installed mainly during the construction of walls. The blocks are transported to the installation site by lifting mechanisms.
Before installation in the opening, the surfaces of window and external door blocks are adjacent to stone walls, they are antiseptic and protected with rolled waterproofing materials (roofing felt, roofing felt). When antisepticizing window and door frames around the perimeter during construction, they are treated with antiseptic pastes using hydro- or spray guns. The paste should be applied in an even layer without gaps. When the ambient temperature is below 0 °C, the paste is heated to a temperature of 30–40 °C.
After applying the paste and drying it around the perimeter, strips of roofing felt and roofing felt are attached to the box with small nails with a width equal to or slightly greater than the width of the box. Before lifting the block into the design position, the sashes or door leaf should be secured to the mounting hooks (for individual lifting). The blocks are lifted with a two-legged sling. At some construction sites, blocks are assembled into apartments and lifted by crane in a container.
To guide the block into the design position, use a thin steel or hemp rope, which is temporarily attached to the vertical bar of the box. The block must be lifted carefully, without jerking, and lowered smoothly to the installation site. Boom turns should not be sharp. After installation, the window frame is aligned horizontally and vertically with a level and plumb line (Fig. 120). The axes of window and door blocks must coincide with the axes of the openings. The coincidence of the axes of the blocks and the openings is checked with a plumb line along the mark of the axis of the opening made on its upper slope, and the cord must pass exactly through the point of intersection of the diagonals of the block box. Block distortions are eliminated using wedges.
The window block is placed freely in the opening, after which it is aligned and wedged in the designed position. Wedging forces should only act on the ends of the box. At the same time, the frame must not be distorted, otherwise the doors and leaves will not open and close well. Before installation, it is necessary to check whether the windows, sashes, transoms, and door panels open and close well. After installation, the gaps between the doors, leaves and frames should not exceed 2 mm, between internal doors and the floor - 5–8 mm, between doors and the floor in bathrooms - 12 mm.
Rice. 120. Checking the correct installation of the window frame in the opening: 1 – reinforced concrete lintel; 2 – wedges; 3 – window box; 4 – gap for caulking; 5 – plumb line
When installing window and door blocks, all elements of the same name are placed on the same line, for example, on the facade of a multi-story building, the vertical bars of the frames should be on the same vertical line.
When installing a door block in an opening, it is leveled and plumb both in the plane of the wall and across it so that the frame of the block does not protrude beyond the plane of the wall if the walls are not plastered. With plastered walls, the frame must protrude beyond the plane of the wall by the thickness of the plaster so that the platband is adjacent to the wall and the frame.
Before attaching the block, check whether the box is warped. To do this, the block is measured diagonally, pulling the cord from one corner to the opposite. You can also check the skew of the box with a plumb square.
Boxes installed in openings of external walls must be spaced at the same distance from the plane of the wall into the building along its entire façade.
Frames of window and door blocks are secured to stone walls and partitions with screws or steel brushes, which are driven into antiseptic wooden plugs embedded in the walls. The vertical bars of the boxes are attached to the openings in at least two places, and the distance between the screws and ruffs should be no more than 1 m. The boxes are connected to wooden partitions with nails.
After installing the blocks into the opening and securing them, the gaps between the frame and the masonry of the external walls must be caulked with heat-insulating materials. They caulk with steel caulks. In residential buildings, window and balcony blocks are usually installed in a common opening. For better fastening blocks, it is advisable to install an additional plug or metal embedded element in the upper part of the opening (slope) at the junction of the blocks.
Window and balcony blocks are fastened together with nails, laying a 10–20 mm thick batten between the blocks, half the width of the frame, so that the remaining gap can be caulked later.
To seal windows and balcony doors, as well as joints in external panels in high-rise buildings, mastic sealant made of polyisobutylene styrene is used. The mastic adheres well to the surface of wood and concrete; at positive air temperatures, mastic can be used without preheating.
Door blocks are installed in openings of brick walls using a crane. The vertical bars of the door frame are secured with ruffs driven into antiseptic wooden plugs placed when laying the walls.
In block and panel buildings the box is fastened into embedded wooden antiseptic plugs measuring 50×80×120 mm. In some construction projects, door blocks are installed during the process of laying walls. To better fasten the boxes to the masonry in height, pieces of wire are nailed to the vertical bars, which are then placed in the seams and sealed with mortar.
When installing door frames in walls (Fig. 121, a, b) You need to make sure that the box is not skewed. When installing door blocks in partitions (Fig. 121, c), it is desirable that they do not protrude from the plane of the partition. Due to the fact that the partitions are about 80 mm thick, boxes with a width of 74 mm are used for installation in the opening.
Within the walls wooden houses(chopped, cobblestones) in the openings on logs, beams, a comb is cut, then a box is installed, which in outside has a groove that fits into the ridge. The gap formed between the box and the wall is caulked from the outside and inside of the room.
Rice. 121. Examples of installing door blocks in internal walls and partitions: a – c brick walls; b – c wall panels; c – in the partitions; 1 – option with plaster; 2 – platband; 3 – rack
Rice. 122. Installation of window blocks in the openings of stone walls of residential and public buildings: a – with paired sashes; b – with separate bindings; 1 – platband; 2 – wooden plug; 3 – ruff; 4 – caulk; 5 – sealing material
The installation of window blocks in the openings of stone walls of residential and public buildings is shown in Fig. 122. Window units with separate sashes can be installed as a whole or separately: first the outer unit, and then the inner one. It is necessary to ensure that between the outer and inner boxes there were no gaps, i.e. they should be tightly fitted to one another and firmly fastened with nails.
The procedure for installing door frames in standard houses frame structure is shown in Fig. 123. In the outer wall (Fig. 123, a, b) the box is adjacent almost closely to the frame posts. After securing and caulking the gaps, the box is covered on both sides with a lining.
In the partitions (Fig. 123, c, d) after installation, the box is finished with a platband or platband and lining.
Installation of the box to the furnace is shown in Fig. 123, d. During installation, the box is insulated from the stove with fire-resistant material.
Rice. 123. Installation of door frames in wooden houses frame structure: a, b – in the outer wall; c, d – in the partitions; d – adjacent to the furnace; 1 – door frame block; 2 – gypsum sheathing sheets; 3 – thick paper (air insulator); 4 – sparse wood paneling; 5 – frame frame; 6 – wooden lining; 7 – felt soaked in clay; 8 – platband; 9 – solid fiberboard; 10 – mineral felt (insulation); 11 – bituminized paper (vapor barrier); 12 – soft fiberboard; 13 – outer skin
After attaching the frame to the wall, the door leaf is removed from its hinges so as not to damage it during finishing (plastering) work. The ends of the vertical bars of the box are embedded in the floor to the designed depth. The gap formed between the frame and the wall of the opening is caulked, and the slopes are plastered.
After completing the finishing work, the door leaf is hung again on the frame, checking its fit to the quarters of the frame.
The window sills of balcony and external doors are sealed with elastic gaskets, secured after painting and glazing the blocks.
Airtightness of window and balcony blocks, especially with paired frames and panels, can be prevented by using devices that ensure their tension.
To ensure a tight fit to walls or partitions, the platbands are attached with an overlap of at least 10 mm. The correct installation of the platbands is checked with a plumb line, level and square. They are attached to the box with nails with slightly recessed heads. In the corners they are connected by a mustache. Platbands made of valuable wood species (oak, mahogany, rosewood, etc.) are secured with screws. Platbands installed in the same room must have the same profile. Window and door blocks are glazed after they are painted.
Wooden window sill boards are installed mainly in wooden houses, but they are also made in stone buildings after settlement and plastering and sanitary work.
In one room, window sill boards should be on the same level. The lower surface of the window sill boards adjacent to the stone surfaces must be antiseptic and insulated from the masonry walls with felt. To avoid moisture retention, the upper surface of the window sill boards should have an inward slope of 1%. In stone buildings, the ends of the boards embedded in the walls are antiseptic and insulated from the masonry with roofing felt, roofing felt or other waterproofing material. The length of the ends of the window sill boards embedded in the walls is about 40 mm.
4. Installation of joinery partitions
Partitions are installed after flooring, sanitary and electrical work, plastering of walls and glazing of windows.
Carpentry partitions made from ready-made boards of frame (panel) construction are installed on a plank pad laid directly on the floor.
The partition can be equal to the height of the room or slightly lower. Before installation, the boards must have smooth edges, that is, they must be well jointed. The panels are connected using plug-in tenons and screws, screwed at an angle to the connection point. The number of spikes depends on the height of the partition: less than three spikes are not installed. The junctions of the boards are covered with layouts attached to the boards with screws or small nails with recessed heads.
The partitions are attached to the floor with screws, and to the walls - with fasteners. The junctions of the partitions with the walls and floor are covered with plinths. If the partition reaches the ceiling, it is covered with a figured cornice.
Partitions made from valuable wood are varnished after installation, and those made from coniferous wood are painted with oil or enamel paints. When installing partitions, make sure that they are in a vertical position. Vertical installation of partitions is checked with a plumb line. The deviation from the vertical should not exceed 3 mm per 1 m, and for the entire height of the room - no more than 10 mm.
Partitions made of smooth panels are installed in the same way. Frame partition assembled from factory-made blocks in a horizontal position on the floor at the installation site, and then raised to a vertical position and secured to the floor with nails, and to the walls with ruffs or nails, after which they are lined on both sides with plywood covered with veneer made from valuable wood, painted fibreboards or slabs with a pattern imitating valuable wood. If, according to operating conditions, the partition must be soundproof, one or two layers of soft fiberboard or mineral wool boards are placed inside the frame. After assembly and installation, use a plumb line to check the verticality of the partition. When attaching partitions to stone walls, antiseptic wooden plugs are installed in them in advance. Boards or plywood intended for cladding the partition must have a flat surface without depressions or bulges. The slab and plywood are attached to the frame with nails. The joints of adjacent slabs are covered with profile layouts.
5. Installation of panels, vestibules. Installation of profile parts
Panels (finishing) are installed in rooms in which sanitary and technical plastering work, and the walls were dried.
Before installing the panels on the walls, mark the installation locations of the frame bars, based on the size of the panels, as well as the room. The frame (bars) is attached with screws or ruffs to antiseptic wooden plugs installed in the walls. The frame consists of bars with a cross-section of 25×80 mm. The spacing of the bars depends on the panel size (width). The moisture content of the frame boards should be no more than 15%.
The panels can be assembled into a batten, tongue and groove, and quarter. The assembled frame must be strictly aligned vertically.
The panels are installed on the floor. Cladding the walls with panels begins from the corner of the room, pressing the panel to the frame and checking the verticality of the side edges, and then it is nailed to the frame bars with nails 40 mm long in increments of 300–400 mm. The nails are first driven at an angle into the groove, and then they are finished off with a hammer and the heads are pressed in with a hammer. Then a key (rail) is driven into the groove (Fig. 124, A) and install the next panel. When fastening panels into a groove and tongue (Fig. 124, b) the first panel is installed and secured in the same way as described earlier. The second panel is installed close to the frame and the ridge is driven into the groove with a hammer blow, and on the other side of the groove it is fastened with nails to the frame. The panels fit tightly to each other.
The panels are fastened with layouts as shown in Fig. 124, V. They are attached with nails to the frame strictly vertically, leaving a small gap, and after checking the verticality, layouts are inserted into the seam and secured to the panels with nails or screws. The panels at the joints must be carefully adjusted to one another. The joints (connections) of the shields are covered with layouts - flashings. The top of the panel is trimmed with a cornice, which closes the gap between the panel and the wall. The cornice is secured with screws or studs to the frame bars. The bottom of the panel is trimmed with plinth.
Tambours are mainly assembled from ready-made panels. Before installation begins, it is necessary to mark the installation locations of the vestibule elements. Installation of panels usually begins with the installation of one of the side walls, then the door block and the second wall, ceiling panels.
If the height of the vestibule is high and massive doors are hung, a frame is built, to which panels of the side walls, ceiling and door block are then attached. The vestibule frame or panels (without installing the frame) are attached to the walls with fasteners or angles.
The panels and door block are aligned vertically and fixed, and then fastened. The panels are fastened together with screws or metal fastenings, door block with panels - also with screws.
The vestibule floors are installed after the walls are installed. The gaps between the walls and the panels are closed with layouts.
Rice. 124. Panel installation diagram: a – fastening with a rail; b – fastening in groove and tongue; c – quarter fastening with layout; 1 – key-rail; 2 – nails for attaching panels to the frame; 3 – wall; 4 – nails for fastening the frame bars to the plugs; 5 – frame block; 6 – panel; 7 – layout
Rice. 125. Installation diagram of regular (a) and slotted (b) skirting boards: 1 – layout; 2 – gasket
The process of installing skirting boards (Fig. 125) on wooden floors consists of the following sequential operations: drilling holes in walls, partitions with a diameter of 15 mm, a depth of 50 mm in increments of 1000–1200 mm at a height of 25–35 mm from the floor level: driving wooden antiseptic plugs into the holes; cleaning floors and walls from contamination; cut the skirting boards to length with a miter cut; fastening skirting boards to plugs. The plinth is secured to the wall with nails driven into wooden plugs. Slit plinth is used when the distance between the wall and the floor exceeds 15 mm. For a better connection to the wall, a groove with a depth of 2 mm and a width of 32 mm is chosen in it.
The platbands framing the openings in the corners are connected “mustache” by cutting them. At the joints, the mustache connection must be tight, without gaps. With a transparent finish, the platbands are selected according to texture before installation. Platbands installed in the same room must have the same profile. Vertical and horizontal platbands are installed at right angles. The correct installation is checked with a plumb line and a square. Platbands and baseboards are installed in the room after plastering the walls and before wallpapering the walls.
When attaching baseboards and trim with nails, the caps are recessed with a hammer, and the cavity is filled with putty before painting. The installed plinth and platband must adhere tightly to the surface.
Wooden handrails are attached to wooden handrails with screws and nails, and to metal handrails - with countersunk bolts. IN Lately handrails made of polyvinyl chloride are used.
6. Installation of built-in wardrobes
Built-in furniture (cabinets, mezzanines) is installed after laying the floors in the room, performing plastering and sanitary work.
Cabinets are assembled from ready-made elements on the floor. They are attached to the floor, ceiling, walls with nails, screws and bolts. The cabinet elements are attached to the walls using wooden plugs into which screws are screwed or nails are hammered. The cabinet elements are assembled together using bolts or screws.
The rigidity of the cabinet is ensured by the strong connection of the walls with the door blocks, as well as with the bottom and top parts wardrobe (mezzanines, etc.). The cabinet elements are connected with bolts or screws only after checking the correct installation. The verticality of the installation is checked with a plumb line and a square.
In the closets, after they are installed, shelves or rods for dresses are installed in place. Types of connections for built-in wardrobe elements are shown in Fig. 126 a B C. The cabinet elements adjacent to the floor, i.e. the bottom of the cabinet, are covered with a plinth. The junction of the cabinet with the walls is finished with slats or platbands. Depending on the size, the gaps between the ceiling and the top of the cabinet are closed with a strip or a special cornice.
The shelf separating the mezzanine door from the cabinet door is attached tightly to the side walls of the cabinet, the remaining shelves are made removable, and the shelves are placed on under-shelf bars, metal or plastic shelf holders. To make cleaning the lower part of the cabinets easier, a polish is applied (Fig. 126, G).
Cabinet doors are hung on hinges or card hinges. Card hinges protrude from the outside of the door, so it is more advisable to use special hinges (Fig. 126, d, f).
Rice. 126. Connecting elements of built-in furniture: a – rear and side walls using a block; b – side wall with door block; c – rear wall with intermediate wall; d – details of the lower part of the cabinet; d – loop; e – hanging doors on hinges; 1 - side wall; 2 – screw; 3 – block; 4 – back wall made of particle boards; 5 – door frame block; 6 – door leaf; 7 – intermediate wall made of solid wood fiber boards; 8 – floor (bottom) made of plywood or hard fiberboard; 9 – floor boards; 10 – plinth; 11 – card loop, console, chrome-plated.
Handles are used to open cabinet doors. The cabinet doors are closed with latches consisting of an aluminum body and a latch mounted into it. The latch has a button for movement. Doors are hung so that they close tightly and do not spring when opening and closing. Door leaves and other cabinet elements covered with valuable wood veneer are finished with varnish, and if the cabinet elements are made of plywood, solid fiberboard or particle boards without veneer, they are painted with nitro enamel or oil paint to match the walls. In some residential buildings the surfaces of the cabinets facing the room are covered with the same wallpaper as the walls, and internal surfaces covered with drying oil or oil or enamel paints.
On construction sites, cabinet elements have to be manufactured on site from particle boards 16 or 19 mm thick. In accordance with the working drawings, the dimensions of the cabinet elements - walls, doors, shelves - are applied to the sheet, after which they are cut out with a circular electric saw, hacksaw, etc. In those elements in which it is necessary to install wooden trim on the edges, select a groove on the edge of the plate, in which a wooden lining with a comb is inserted onto the glue. The lining of the shield elements is made flush with the plane of the shield.
SURFACE FINISHING OF JOINERY PRODUCTS
1. Types of wood finishing
Joinery products are finished with paints and varnishes that protect them from exposure environment. Painted products have a good appearance, are easier to keep clean, and their durability increases.
Types of finishing can be divided into the following main groups: transparent, opaque, imitation, etc.
With transparent finishing, the surface of the wood is covered with colorless finishing materials that preserve or further reveal the texture of the wood. It is used for finishing furniture and high-quality construction products: windows, doors, panels made of valuable wood.
Transparent finishes are achieved by varnishing, polishing, waxing and coating with transparent films. When finishing by varnishing, varnishes are used that contain film-forming substances in organic solvents, solvents, etc.
Most often, polyester, nitrocellulose and urea-formaldehyde varnishes are used for finishing wood, and less often - oil and alcohol varnishes. Nitrocellulose varnishes dry well, produce a transparent, elastic, durable and fairly weather-resistant film that can be sanded well. Varnishes based on urea-formaldehyde resins form a film with a shiny surface that is quite transparent. The film formed by oil varnishes is elastic, durable, weather-resistant, but not decorative enough; alcohol varnishes produce a film with insufficient strength, weather resistance, and low gloss. Depending on the degree of gloss, coatings are classified into glossy, semi-glossy and matte.
When waxing, i.e. applying a mixture of wax with volatile solvents (white spirit, turpentine) to the surface of wood, it also turns out transparencies, formed by a thin layer of wax (volatile solvents evaporate during the drying process). The wax coating is usually applied to porous wood (oak, ash). The wax film is soft, so it is covered with an additional layer of alcohol varnish. The wax coating has a matte surface.
With an opaque finish, a film is created on the surface that covers the color and texture of the wood. Opaque finishes are used in the manufacture of school, kitchen, medical, built-in and children's furniture, doors, and windows.
For getting opaque coating use oil, nitrocellulose, alkyd, perchlorovinyl, water-based paints and enamels.
When painting with enamels with a high content of film-forming substances, glossy coatings, with a smaller amount - semi-gloss, and when painted oil paints– matte.
Imitation finishing improves the appearance of products made from wood, the texture of which does not have a beautiful pattern. The main methods of imitation finishing are deep dyeing, pressing of textured paper with a pattern of precious wood, finishing with veneer, films, and sheet plastic.
Surface finishing using the airbrush method involves applying paint with an airbrush gun and creating a pattern (using a stencil). Using airbrushing, designs with planar (ornaments) and three-dimensional images can be applied to surfaces.
Lamination is one of the types of imitation finishing and consists of lining chipboard or fiberboard with paper impregnated with synthetic resins. When pressing boards covered with paper between metal spacers at a pressure of 2.5–3 MPa and a temperature of 140–145 °C, a smooth and shiny surface is obtained on the boards.
The performance qualities of paint and varnish coatings must have a number of physical and mechanical properties: adhesion to wood, hardness, heat, light and water resistance. These properties are of significant importance in the operating conditions of the products. They are determined by the quality of paints and varnishes, the conditions of their application, and drying of coatings.
Adhesion refers to the strength of adhesion of the paint coating to the surface of wood, while hardness refers to the resistance of the paint coating to the penetration of a harder body into it.
Water resistance is the ability of a coating to withstand the effects of water on the surface of a product. It plays a very significant role in the operation of carpentry products (window blocks, external doors) in conditions of variable humidity.
Paint and varnish coatings must be heat-resistant, i.e. not destroyed when heated sun rays or other heat sources. In addition, they must be elastic, since when atmospheric conditions change, paint coatings dry out or swell, as a result of which cracks form, coatings wrinkle or peel off.
2. Preparing the surfaces of parts and products for finishing
Carpentry preparation. Carpentry preparation includes sealing knots, cracks, removing dirt, cleaning the wood surface and subsequent sanding. Knots and cracks are repaired manually or using machines.
Cracks in parts are repaired by gluing in wooden inserts selected by size and species and cleaning the surfaces, and in parts lined with veneer by gluing in strips of veneer of a similar species, selected by color and texture. Small cracks are greased and puttied.
The surface of the wood is cleaned with a sander. After sanding with a sander, the surface of the wood should be even, smooth and free of burrs, even in places where there is curling. Irregularities from the cleaned surface are removed with a hand scraper, which is a thin rectangular steel plate measuring 150×90×0.7–0.8 mm. The cutting part of the cycle is sharpened at a right angle so that it forms two sharp rectangular edges.
The cycle is held with both hands at an angle at which it can cut, and somewhat obliquely, directing the movement towards itself. In order to make your fingers less tired when working with scrapers, it is recommended to use a block into the slot of which the scraper is inserted.
A good scraper should be thin, slightly elastic, hard, properly sharpened and aimed. The size and shape of the cycle should be such that it is comfortable to hold in your hands.
When stripping wood, the cycle usually does not cut it, but rather scrapes it, that is, it removes the top thin layer, leaving behind the smallest pile. When processing hardwood, this pile is small and has no practical significance, but when processing softwood, it is visible to the naked eye and noticeable to the touch, so species such as aspen and linden are not processed with scrapers, but are sanded.
Grinding smoothes the surface and also eliminates paint defects - craters, bubbles, shagreens, waviness, raised pile, etc., obtained after applying primer, putty, the first layer of varnish or paint.
Can be sanded manually or electrically grinding machines or on belt sanding machines. Flat surfaces are sanded smooth and even wooden blocks, wrapped in sandpaper, from corner to corner, and then along the grain. It is not recommended to sand across the grain, because it will form on the surface. deep scratches, which are difficult to clean.
Coatings are sanded wet method using kerosene, turpentine, or dry, without the use of coolants, to cool the surface being sanded. The surface of the wood is sanded first with coarse-grained sandpaper, then with medium-grained sandpaper, and then with fine-grained sandpaper. It is necessary to grind without much effort, since with strong pressure the quality of grinding deteriorates. Before finishing sanding, remove dust from the surface of the wood with a rag and then moisten it with water to raise the pile; The raised pile can be easily removed with sandpaper. A well sanded surface should be smooth, clean and silky to the touch.
Pastes, powders, and sandpapers containing abrasives in the form of small grains with sharp edges are used as grinding materials.
Grinding powder is dry abrasive grains not bound by binders.
Abrasive cloths are a flexible base on which the abrasive grains are secured with a bonding material. The skins are produced on a fabric or paper basis in rolls and sheets. Sheet sandpapers are used for manual sanding, while roll sandpapers are used for mechanized sanding. Sanding pads are available in waterproof and non-waterproof types; Based on the type of abrasives used, a distinction is made between corundum, electrocorundum, and silicon carbide. Depending on the type of coating being sanded, sandpapers of different grain sizes are used: coatings after local puttying - 16, 20, 25; coatings with continuous putty – 10, 12; primed coatings and first layers of varnishes and enamels – 6, 8; final sanding of varnish and enamel coating – 3.
Finishing preparation. In preparation for a transparent finish, the surface of the wood must be thoroughly cleaned, sanded, de-tarred, bleached, and primed.
Resin removal is carried out on coniferous wood, for which the surface of the wood is washed with a solvent (turpentine, benzene) or wiped with a hot 5% solution of caustic soda; the resin on the surface is saponified, after which it is washed off with warm water or a 2% soda solution. Bleaching removes stains of translucent glue and traces of oil. Bleaching (except for oak wood) is carried out with a 6–10% solution of oxalic acid, a 15% solution of hydrogen peroxide with the addition of a 2% solution of ammonia. The solution is applied to the surface of the wood with a brush or brush. After 3–8 minutes, it is washed off with warm water. Bleaching solutions are poisonous, so you should use goggles, rubber aprons and gloves when working with them. After bleaching, the surface of the wood is sanded.
Dyeing gives the wood the required tone or color and is also used to imitate low-value wood to look like valuable wood. For transparent wood finishing, dyeing should not change its natural color.
Dyeing can be deep or superficial. With deep dyeing, the entire wood is impregnated; with surface dyeing, the depth of impregnation is up to 2 mm. The most commonly used surface dyeing is water-soluble dyes.
Surface dyeing is done manually using a swab, dipping method, pneumatic spraying, roller method, etc.
Small parts are painted by hand with a swab. The tampon is made from linen fabric, which does not leave fibers on the surface of the wood. Horizontal surfaces They are dyed along the fibers in wide stripes, and the dye is applied to the vertical ones from top to bottom. Apply the dye at a solution temperature of 40–50 °C several times until the desired color is obtained. The time gap between each application of paint should not exceed 5 minutes. Excess applied paint is removed with a dry cloth. After the dye has completely dried (2 hours at a temperature of 18–20 °C), the surface of the wood is wiped along the grain or sanded. The paint is applied by dipping in baths with a solution heated to 40–50 °C.
The pneumatic dyeing method is used in the mass production of wood products.
Dyeing can also be done with mordants, which are a solution of chromium - ferrous sulfate, ferric chloride, copper sulfate(0.5–5%). The solution is prepared by dissolving the mordant in hot water and then filter it and cool it. Apply the solution manually by dipping or spraying.
To fill the pores and form a film, creating conditions for better adhesion of the varnish to the wood, the surfaces are primed. Priming is done under transparent and opaque coatings.
The primer is a composition that forms the bottom layer of the coating. Primers consist of a solution of resins, nitrocellulose and plasticizers in a mixture of solvents.
Parts and products finished with acid-curing nitro-varnishes are primed with UkrNIIMOD-54 primer. The primer is a solution of urea and oxyterpene resins in solvents with an additive adhesive solution and drying oils "Oxol". The hardener is water solution oxalic acid.
The surface of the wood after applying emulsion primers GM-11, GM-12 does not require sanding. These primers do not raise lint and show the wood texture well; they are applied with a swab and rollers. Thick primer is applied with a spatula, and liquid primer with a swab. When applying with a swab, the primer is rubbed into the surface of the wood, making circular movements. Excess soil is removed with a dry swab, moving it along the fibers.
Parts made from wood of large-porous species are subjected to a pore-filling operation. Before applying the filler, the surface of the wood must be clean, smooth, without scratches, with a roughness of no more than 16 microns. The use of fillers reduces the consumption of varnish for wood coating.
Special compositions KF-1 and KS-2 are used as porosity fillers. Tinted foam filler is used for finishing products lined with oak, ash, walnut, mahogany, urea-formaldehyde and hot-curing semi-ester varnishes.
Apply the composition with a swab or foam sponge on a flat polishing machine. After application, the filler is thoroughly rubbed with a swab alternately along and across the wood fibers, after which the surface is wiped with a flannel cloth and then dried for 2 hours in a room at a temperature of 18–23 °C.
A composition in the form of mastic is also used, which simultaneously primes and serves as a filler for a transparent finish. Most often, wax paste is used for this purpose (1 part wax dissolved in 2 parts turpentine or gasoline). Paste prepared with gasoline dries faster (6–8 hours) than paste made with turpentine (20–24 hours), but it is more flammable.
Apply the paste to the surface of the wood using a stiff hair brush in an even layer. When the surface is completely dry after applying the paste, rub it with a brush with hard, short and thick bristles, and then with cloth until shiny. The surface covered with wax is finished with transparent varnish. At some enterprises, waxing is replaced by drying.
Puttying is used for opaque finishing of wood products. It is intended for leveling the surface and eliminating small cracks and dents. Puttying can be local or continuous. With local putty, minor defects are repaired; continuous putty improves the appearance of the finished product. Putty primed and unprimed surfaces before covering them with paints or enamels.
Depending on the film-forming substances, putties can be oil-based, adhesive, nitro-lacquer, polyester, etc. The most commonly used are oil-adhesive putties, thick or liquid.
Thick putty is prepared from a mixture of drying oil (25%), precipitated chalk (70%), adhesive 10–20% solution in an amount of 5%, liquid putty is prepared from the following mixture: 28% drying oil, 65% chalk and 7% adhesive 10 –20% solution.
For filling carpentry, use quick-drying putty KM, consisting of the following components (in% by weight): KMC glue (9%) - 18.5; casein glue (22%) – 1.9; latex SKS-30 – 3.9; laundry soap (10%) – 1; asidol – 2; chalk – 72.6; lime – 0.1.
3. Finishing the surfaces of parts and products with paints and varnishes and cladding
The prepared wood surface is coated with varnishes, paints or enamels. The varnish film gives the product a beautiful appearance and protects the surface from moisture.
With an opaque finish, the wood is painted with oil paints - white and PF-14 enamels based on pentaphthalic resins. Minimum thickness the film should be 50–70 microns. Zinc white is used for painting carpentry.
The sequence of technological operations performed when preparing parts for painting indoor surfaces with oil, enamel and synthetic paints is as follows: cleaning surfaces, cutting out defects (knots, tars) with filling of cracks, sealing (priming), partial greasing with sealing of greased areas, grinding of greased areas places, first painting, second painting, and with higher-quality painting - cleaning, cutting out wood defects, waxing (priming), partial priming with waxing of greased places, sanding of greased places, continuous putty, grinding, priming, fluting, sanding, first painting, fluting, sanding, second painting, fluting or facing.
Carpentry outside and inside the premises is painted with oil, enamel and epoxy paints. Indoor carpentry and built-in furniture are painted with PVA-type polyvinyl acetate, oil and acrylate paints.
The surfaces of parts and products painted with oil, synthetic, enamel and varnish compositions must have the same texture - glossy or matte. Stains, marks, wrinkles, unevenness, brush marks, drips and show-through of underlying layers of paint, unpainted paint are not allowed.
Application of paints and varnishes by hand. On narrow surfaces (edges) varnishes, paints, enamels are applied with hand-held brushes - short round bristled brushes of the KR type, on wide surfaces - with wide flat brushes or paint rollers. Instead of brushes, you can use brushes and swabs.
The varnish is applied to a dry wood surface, free of dust, in uniform layers without drips approximately 3-6 times. Each layer of varnish must be thoroughly dried before applying the next. The product is considered finished if its surface has a uniform and even shine.
High-quality products are finished with polishing, as the polished surface has a stable shine and good appearance.
Polishing is performed by manual and mechanized methods. To protect against contamination, drying out and fire, tampons are stored in a metal box.
Mechanized application of paints and varnishes. Spray paints and varnishes using mechanical and pneumatic methods. The most widespread is pneumatic spraying, in which, under the influence of compressed air, paint and varnish materials are crushed and fine particles settle on the product being painted, spreading over its surface and forming a continuous coating. This method of finishing wood also has disadvantages: applying paint requires special chambers equipped with exhaust and cleaning devices; When spraying, up to 20–40% of the paint is lost to the formation of paint mist, which worsens sanitary working conditions.
A more advanced way of finishing carpentry is painting in an electric field high voltage followed by drying in thermoradiation-convective chambers. The essence of the painting process in a high-voltage electric field is as follows: a constant high-voltage electric field is created between the product being painted, which has a positive charge, and the sprayed particles of paints and varnishes, which have a negative charge. Sprayed particles of paint and varnish materials move along power lines electric field and are deposited on the product. In Fig. 127 shows a diagram of painting carpentry in a high voltage electric field. The products are hung on a conveyor chain, which feeds them into the normalization chamber to be coated with a special electrically conductive composition, then by the same conveyor they are sent to the painting chamber. After painting with enamels, the products enter a thermoradiation-convective drying chamber.
Rice. 127. Scheme for painting carpentry products in a high voltage electric field: 1 – place for hanging products; 2 – place of removal of products; 3 – conveyor chain; 4 – area for installing electric heaters; 5 – convective drying zone; 6 – asterisk; 7 – drying thermo-radiation-convective chamber; 8 – electrical painting chamber; 9 – normalization chamber
The quality of painting of joinery products in an electric field is affected by the moisture content of the wood. Thus, when humidity is below 8%, the quality of painting deteriorates.
When painting carpentry products in a high-voltage electric field, almost all processes are automated, losses of paint and varnish materials are significantly reduced, sanitary and hygienic conditions for working in the workshop are improved, the area for painting is reduced and the quality of painting the surface of products is improved.
Paints and varnishes are also applied to carpentry using the jet spray method. Products (windows, doors) are hung on an overhead conveyor moving into the pouring chamber, where paint or enamel is applied to the surface, flowing from nozzles under pressure up to 0.1 MPa in the form of a jet. After painting, the products enter a holding chamber in solvent vapors. In this chamber, in addition to swelling of excess paint, it is evenly distributed over the entire surface of the product. Excess paint flowing from the products flows through the tray into collections and, after filtration, into the pouring system. After holding in the chamber, the products enter a convective multi-pass drying chamber. The disadvantage of the jet coating method is poor coverage of edges and slightly increased paint consumption.
Paint and varnish materials for flat surfaces applied on rolling machines, which are included in automatic lines, where the following operations are sequentially performed: heating the door leaf, priming, drying, grinding, heating the leaf, varnishing, drying. Flat parts (boards, doors, slabs) can be finished using a varnish-filling machine (Fig. 128). The main part of the machine is the filling head. The process of applying paints and varnishes in bulk consists in the fact that the parts placed on a conveyor are fed under the filling head, from which the paint and varnish material flows down in the form of a continuous curtain and covers the parts evenly over the entire width with a layer of paint and varnish of equal thickness.
Compared to pneumatic spraying, dousing reduces the loss of paint and varnish materials and improves sanitary working conditions in the workshop.
Rice. 128. Scheme of a coating machine: 1 – detail; 2 – screen; 3 – drainage dam; 4 – collector; 5 – partition; 6 – filter; 7 – coating; 8 – conveyor; 9 – tray
Drying paint and varnish coatings. After applying paint and varnish coatings, the products are dried in drying chambers, which, depending on the design, are divided into convective, thermo-radiation, thermo-radiation-convective. Cells can be pass-through or dead-end.
The drying time of paints and varnishes depends on the type of paint, the thickness of the layer and the temperature of the environment in which the coating is dried. There are three ways to speed up the drying of paintwork: by accumulating heat in the wood (preheating the wood), convection and thermo-radiation.
The process of heat accumulation is as follows: before painting, the surface of the product is preheated to a temperature of 100–105 °C, then painted and fed into another chamber for drying. Since the product has been preheated, when passing through the second chamber, the solvents quickly evaporate and the surface dries. This method is especially effective when finishing with quick-drying paints and varnishes: the drying time of the coating and the consumption of solvents are reduced.
During convective drying, heat is transferred from the source to the painted surface by air heated to 40–60 °C. Due to the low calorific value of air, heat is transferred slowly from the painted surface, therefore the surfaces of the products also dry slowly.
A more rational method is the thermoradiation method of drying paint and varnish coatings, which speeds up the drying process itself and requires smaller chambers. The drying process is shortened due to the absorption of infrared rays emitted by heated tubular heaters on the surface to be painted.
The surface of painted products, absorbing infrared rays, heats up, starting from the bottom of the paint coating, which allows heated solvents to evaporate freely.
As solvents evaporate and pass through the paint layer, they simultaneously heat it up, which causes intense heating of the entire paint layer and significantly speeds up drying.
For cladding walls and partitions, laminated paper plastic is used - sheet material, obtained by pressing at high blood pressure special papers impregnated with urea or phenol-formaldehyde resins. Laminate comes in a variety of colors with a glossy or polished finish. It is quite strong, waterproof, durable, and easy to clean.
Plastic with a thickness of 1–1.6 mm is attached to the surface using mastics (KN-2, KN-3), and plastic with a thickness of 2–3 mm is attached to a wooden frame.
Finishing the surface of walls and partitions with sheets of plastic begins with the bottom row from the corner of the room.
The sheets are joined together both vertically and horizontally.
Before work begins, the sheets are cut to size, the edges are jointed, and the correct joining of the edges is checked. The mastic is applied to the back side of the sheet in an even layer no more than 1 mm thick. The smeared side is carefully applied to the surface of the wall without displacement or distortion, after which it is rubbed evenly with a rag, first in the middle of the sheet, and then alternately left and right, up and down. Excess mastic and dirt are removed with a swab soaked in acetone. A rustication (gap in the wall) 5 mm wide is left between the sheets. The position of the sheets until the mastic sets is fixed with inventory clamping devices. The seams between the sheets are painted with water-based paints or sealed with KN-2 mastic with baseless polyvinyl chloride film.
To fasten sheets of plastic, instead of mastic, you can use wooden, polyvinyl chloride and metal layouts. In this case, wall cladding begins from the corner of the room, attaching vertical corner and horizontal layouts, checking their position according to plumb and level, then installing the first sheet and placing the second layout, etc.
Fix the position of the plastic sheets on the surface of the wall or partition before attaching them with nails hammered into pre-drilled holes. As the sheets are secured, the nails are pulled out. The layouts are placed so that they cover the nail holes.
The layouts are attached to the walls with screws with a pitch of 150–200 mm, for which holes with a diameter slightly larger than the diameter of the screw are drilled in the plastic sheets according to the markings.
After cladding, stains, mastic drips, scratches, voids between the plastic and the wall, partition, swelling of sheets, etc. are not allowed on the surface of the laminated plastic.
4. Mechanization of finishing carpentry and built-in furniture
A number of flow-mechanized and automated lines have been created for finishing wooden parts and built-in furniture products. The lines are designed to prepare parts for varnishing and finishing, as well as painting.
The line for painting door panels, including those for built-in furniture, using the rolling method consists of a mechanism for applying paint and a drying chamber. They work on the line like this: a conveyor moves the door leaf under a tank, from which paint flows out in a continuous stream, leveled by three foam rollers. Using the mechanism, the rollers and the tank continuously move across the door leaf, rubbing the applied paint evenly over the surface of the door. The door edges are painted using two vertical rollers. After covering the first layer with paint, the door leaf enters a convective drying chamber, where the coating dries for 4 minutes at a temperature of 60–80 °C. Then the canvas is turned over (turned over), and the other plane of the door is painted in the same way. Doors measuring 2000 x 800 x 40 mm are painted on line.
Doors lined with precious wood are finished with varnish on mechanized lines. The door leaf from the table is fed into a thermo-radiation chamber equipped with electric heaters (heaters) with a temperature of 410 °C. The door leaf passes through the chamber for 64 s, while its surface is heated to a temperature of 105 °C. After warming up, the canvas is fed to the machines and edge spraying machine for priming the surfaces and edges. The primer is applied to the plane of the door leaf in the machine using two rollers covered with corrugated rubber, and to the edges using spray guns. The door leaf, covered with pound, enters the drying chamber, which is equipped with a deflector. Due to the fact that the door leaf has been preheated, solvents evaporate faster when passing through the chamber.
The blade is then fed to grind one plane first into a first grinding machine equipped with a cylindrical brush. The door leaf, sanded on one side, is turned over to the other side by a rotating device (tilter) and fed to the second two-cylinder grinding machine for grinding the other plane. The door leaf, sanded on both sides, is fed into the second thermo-radiation chamber, where it is reheated for 30 s. In this chamber, electric heaters have a temperature of 320 °C. The heated canvas for varnishing both planes and edges enters the machine, after which it is transferred to the drying chamber. The finished web is transported by a roller conveyor to the installation site of the devices.
On the OK515 window finishing line, the following operations are performed: filling defective areas, drying putty areas, grinding putty areas, applying the first layer of enamel, drying the applied layer of enamel, applying the second layer of enamel, drying the second layer of enamel, cooling the enamel.
The line consists of a conveyor for puttying sashes of an overhead conveyor, drying chambers, two jetting installations, three lifting tables, two storage conveyors for sashes (left and right), eight pneumatic polishing machines, eight grinding heads.
The line paints products up to 220 cm high, up to 200 cm wide, and up to 40 cm thick. The temperature in the drying chambers is 60–80 °C.
FLOORING WITH LINOLEUM AND SYNTHETIC TILES
1. Flooring materials
Linoleum, tiles. Synthetic roll and tile materials are used to cover floors. As roll coverings They mainly use linoleum, which is wear-resistant and has sufficient chemical resistance.
Depending on the type of binder, linoleum is produced in the following types: polyvinyl chloride, alkyd, rubber, etc. In addition, linoleum comes with or without a heat-insulating base.
Polyvinyl chloride multilayer and single-layer linoleum without a base are produced in three types: MP - multilayer with a front layer of transparent polyvinyl chloride film with a printed pattern; M – multi-layer monochrome or marble-like; O – single-layer, single-color or marble-like. Linoleum is produced in rolls with a panel length of at least 12 m, a width of 1200–2400 mm, and a thickness of 1.5 and 1.8 mm. It is used for covering floors in residential, public and industrial buildings except in areas with heavy traffic.
Polyvinyl chloride linoleum on a fabric base, depending on the structure and type of front surface, is produced in five types: A – multi-line duplicated with a front layer of transparent polyvinyl chloride film with a printed pattern; B – multi-line with a printed pattern, protected by a transparent polyvinyl chloride layer; B – multi-line single color; G – multi-line two-color; D – single-stroke, single-color or marble-shaped.
The length of the linoleum roll must be at least 12 m, width 1350–2000 mm, thickness 1.6 and 2 mm for types A, B, C and 2 mm for types D, D. It is used for installing floors in residential, public and industrial buildings without heavy traffic and without exposure to fats, oils, and water.
Polyvinyl chloride linoleum on a heat and sound insulating base, depending on the production methods and the structure of the top layer, is produced in five types: PR - promazny; VK – roller-calender; VKP – roller-calender with transparent front polyvinyl chloride film; EC – extrusion; EKP – extrusion with a transparent front polyvinyl chloride film.
Linoleum is produced in rolls 12 m long, 1350–1800 mm wide, with a total thickness of at least 3.6 mm. Intended for installation of floors in residential buildings.
Alkyd linoleum is produced in two grades: A and B, distinguished by physical and mechanical characteristics, thickness 2.5; 3; 4 and 5 mm, length 15–30 m, width 2 m. Used to cover the floors of residential, public and industrial buildings that are not exposed to abrasive materials, acids, alkalis and solvents. Linoleum grade B with a thickness of 2.5 and 3 mm cannot be used for flooring in public and industrial buildings with heavy traffic.
Rubber linoleum (Relin) is produced following types: A, B, C (antistatic). Type A linoleum is intended for covering floors in residential and industrial buildings; type B - for the same premises, but equipped with forced ventilation; B – for covering floors in special laboratories and surgical operating rooms.
During transportation and storage, linoleum is protected from damage, moisture and contamination. The rolls are installed vertically in one row.
Polyvinyl chloride tiles are produced in two types: square and trapezoidal. Square tiles are made in sizes 300×300 mm, thickness 1.5; 2 and 2.5 mm, trapezoidal tiles have the dimensions shown in Fig. 129.
Tiles come in single and multi-colors with a smooth or embossed front surface. There should be no sagging, dents, scratches, cavities, bumps, etc. on the front surface of the tiles. Single-color tiles must have a uniform, color-fast color over the entire area.
Adhesives, mastics and primers. When veneering synthetic materials rubber mastics KN-2 and KN-3 are used from yellowish-brown to dark gray in color, which are prepared from the following components (%): indene-coumarone resin - 10, nayrite rubber - 25, kaolin filler - 25 and solvent - 40 . Galosha gasoline and ethyl acetate are used as a solvent in equal parts. The finished mastic is packaged in metal cans with a capacity of 1–10 kg. KN-2 mastic is used for gluing rubber linoleum and installing underlying layers on concrete and fiberboards. KN-3 mastic is similar in composition to KN-2 mastic, but contains a smaller amount of nayrite, and, in addition to kaolin, it contains chalk. Used for gluing PVC linoleum and tiles, as well as rubber linoleum.
Rice. 129. Polyvinyl chloride tiles for floors (trapezoidal)
Caseinolatex mastic is used for gluing linoleum and fiberboards. Consists (parts by weight) of SKS-ZO ShR latex – 0.8, dry casein OB – 0.04; water – 0.16. The mastic is prepared as follows: pour water into the DV-80 dispersant, add casein and stir the mixture for 2 minutes, then pour in the latex and stir the mixture for 1 minute. The mass after mixing should look like liquid sour cream. After 24 hours the mastic thickens, its validity period is 7 days.
The mastic is applied to the base and back of the linoleum with a notched trowel, then left for 15 minutes, then the panel is glued to the base and rubbed in. The seams between the linoleum sheets are pressed with slats, which are removed after the mastic has dried.
Bitumen mastics can be cold or hot. They are used for gluing wood fiber boards onto the base. Mastics are produced centrally; they arrive at construction sites finished form. Cold bitumen mastic can also be prepared at construction sites in the following composition (% by weight): bitumen grade BN 70/30 - 48, slaked lime - 12, dusted asbestos - 8, solvent - 32. Lime and asbestos are fillers.
Perminid mastic consists (parts by weight): of PVC-LF resin - 18, divinyl-styrene rubber DST-30 - 5, octofor resin - 2.5, ethyl acetate - 58, pine rosin - 2.5, kaolin - 14.
Primers are used to improve the penetration of paints and varnishes (adhesion) to the underlying layer and, in addition, to create a waterproof film that prevents the penetration of moisture from the base. At a construction site, the primer is usually prepared according to the following recipe (parts by weight): bitumen grade BN 70/30 - 1, gasoline or kerosene - 2-3. Gasoline or kerosene is poured into the melted and dehydrated bitumen and then cooled to a temperature of 80 °C and mixed until a homogeneous mixture is formed.
The primer is applied to the base 18–48 hours before gluing linoleum or tiles.
When installing floors made of polyvinyl chloride linoleum on a heat and sound insulating basis, the following adhesives (mastics) are used: polyvinyl acetate bustylate, adhesive gummilake mastic; for installing floors made of polyvinyl chloride linoleum on a fabric base - the same adhesives and, in addition, bitumen-synthetic mastic “Perminid”.
Baseless polyvinyl chloride linoleum and tiles are attached to the base using Perminid, bitumen-synthetic, KN-2 and KN-3 mastics, rubber linoleum - using KN-2 and KZN-3 mastics.
2. Bases for laying linoleum and tiles
In order for coverings made of linoleum and tiles to be of high quality and have a good appearance, it is necessary to arrange rigid bases - smooth, durable and without cracks. Due to the elasticity of linoleum, when laid on uneven bases with depressions or bumps, the coating results in an uneven surface. The evenness of the coating is achieved by installing cement-sand, lightweight concrete and other screeds.
The designs of floors made of linoleum and tiles when laid on various bases are shown in Fig. 130. When laying linoleum and tiles, the moisture content of the base is of great importance. When the humidity is more than 89%, the tiles do not adhere well. High-quality coatings are obtained after drying the bases - cement-sand, lightweight concrete and concrete screeds within 28–42 days.
Plank flooring is also used as a base. It is better to lay linoleum or tiles on them about a year after the building is put into operation.
The screed forms a dense surface over non-rigid or porous floor elements, and also levels the underlying floor element. Monolithic cement-sand screeds made from solutions of grade 150 and higher.
The thickness of the screeds, depending on the underlying layer, ranges from 20–50 mm.
In the case when linoleum on mastic is laid on the screed, it is primed with a bitumen primer.
To avoid cracking, the screed is systematically moistened and sprinkled with wet sawdust for 7–10 days. The evenness of the ties is checked with a level and a rod.
In addition to monolithic screeds, prefabricated cement-sand screeds are used from slabs measuring 0.5×0.5 m, with a thickness of 35 mm or more, which are connected into trapezoidal grooves and ridges. Sometimes, to level the surface of screeds, a polymer-cement mortar is used, consisting of a cement-sand mortar with a PVA polyvinyl acetate dispersion 8–10 mm thick.
Rice. 130. Linoleum floors and polymer tiles: 1 – covering (linoleum, tiles); 2 – mastic; 3 – screed made of lightweight concrete or fiberboard; 4 – concrete underlying layer; 5 – foundation soil; 6 – heat and sound insulating layer; 7 – cement-sand screed; 8 – floor slab with uneven surface; 9 – floor slab.
The solution is prepared at a construction site from a dry mixture (cement and sand), into which a polyvinyl acetate dispersion is added in an amount of 5% by weight of the dry mixture. Before applying the solution, the screed is cleaned of sagging, dirt and dust.
To construct screeds, hard wood fiber boards are also used, which are attached to the base using bitumen mastic. Detected unevenness in the base is eliminated with scrapers or grinders. Fiberboard joints are sealed along the entire length with strips of thick paper 40–60 mm wide. Potholes are sealed with gypsum cement mortar, and small ones are covered with putty. Clean the base from dust and small debris using wet sawdust. The humidity of the base should be no more than 6%.
The plank base must also have a flat surface without sagging. Knots in the boards are sealed with glued plugs. Boards with rot and wear are replaced with new ones. The repaired plank floor is planed to obtain a smooth surface.
3. Laying linoleum
Polyvinyl chloride linoleum is laid in the following sequence: marking, drilling holes in the walls and installing plugs in them for fastening skirting boards, cleaning and leveling the surface of the base, sealing individual defects in the base with a polymer cement composition, priming the base, laying fibreboards with mastic, clearing the seams between the plates with removal bitumen and filling them with a polymer-cement composition, laying out and curing cut linoleum, partially cutting linoleum along the contour, applying mastic to the base and gluing the carpet, rolling linoleum, cutting and gluing linoleum at joints, installing baseboards, covering the floor with sawdust. The procedure for laying linoleum is shown in Fig. 131.
Rice. 131. Laying linoleum: a – cutting and laying out linoleum panels; b – mixing the mastic with a paddle; c – cutting and gluing linoleum; g – rolling.
Linoleum can be laid dry and with mastic. Typically, panels of linoleum, prepared for the size of the room centrally in workshops, are laid out on a dry and clean base and kept in a free state for three days at a temperature of at least 10–15 ° C, and the convex or curved places of the linoleum are loaded with a load (bags with sand) until they are completely level. After this, the linoleum is cut to the walls and partitions using a metal ruler and a knife.
Linoleum carpets are prepared in a room with a temperature of at least 15 °C, and at floor level not lower than 10 °C in the following order: cut the linoleum panels, weld the edges of the joined panels. Welding of linoleum is carried out using the Pilad-220M or SO-104 apparatus. After welding, the carpet is transferred to the curing area.
When linoleum rolls are supplied for construction, they are cut out only after it has been left in a warm room for 2–3 days. At the same time, it acquires elasticity, rolls out well and does not break. The roll must be rolled out carefully so that there are no breaks, after which the panel of the required length is cut with a knife along a ruler, taking into account the allowance for shrinkage (for a length of up to 6 m - 2 cm, and for a length over 10 m - 2-5 cm). The width of the roll is cut so that the edges of adjacent panels have an overlap of 1.5–2 cm. The tool for laying linoleum is shown in Fig. 132. Linoleum panels for cutting and fitting are laid close to the walls and cut in place. The fit should be without gaps, especially in places where the panels have an unclosed joint (at doorways and among themselves).
When cutting there should be as little waste as possible. In the case when the width of the room is not a multiple of the width of the linoleum, the required piece is cut lengthwise from the outer panel, and the remainder is used for installation in another place. Linoleum laid in hard-to-reach places is cut according to templates cut out of cardboard and adjusted to the location. The cut panels are rolled out and kept for at least two days before gluing.
Rice. 132. Tools for laying linoleum: a – metal hammer; b – steel spatula; c – linoleum roller; d – linoleum knife; d – linoleum knife with replaceable blades; e – device for cutting linoleum edges; g – large serrated spatula; h – small serrated spatula; and – rubber hammer.
Linoleum can be laid indoors only after all construction, installation and finishing work has been completed. The room temperature should be no lower than 15 °C, and the relative air humidity should not exceed 70%. The linoleum panel laid on the base is bent to the middle with the back side up, then mastic is applied with a spatula to a dry, dust-free base, leaving strips 100 mm wide at the junction of the panels uncoated. A thin layer of mastic is applied to the back side of the panel, after which the bent and smeared part of the panel is glued to the prepared base. Then glue the second half of the panel and the edges. After laying the panels on the base, the surface is rolled with a vibrating roller (CO-153) to evenly distribute the mastic and increase the adhesive strength.
Glued linoleum does not have hermetically sealed joints. Sealing is achieved by welding. You can weld plasticized linoleums with a small filler content (polyvinyl chloride). The thickness of the adhesive layer should not exceed 0.8 mm.
You can stick linoleum in another way. To do this, the panel is rolled up to the middle of the room into a roll with the front side inward, then mastic is applied to the base, after which the linoleum is glued by rolling out the roll. The glued panel is rolled with a vibrating roller. When cutting edges, adjacent panels should overlap each other by 1.5–2 cm. When gluing linoleum on KN-2 mastic (quick-hardening), the edge is cut simultaneously with laying the linoleum, and when using bitumen mastics(drying slowly) – after 2–3 days. The edges of the panels should fit tightly against one another and form an invisible seam. On overlapped edges, the joint is cut along a ruler sharp knife(Fig. 133) (both panels at the same time). After cutting, carefully lift the edges, clean the back of the panels and the base underneath them and apply mastic, after which the edges are pressed to the base and carefully rolled with a roller.
Rice. 133. Cutting the linoleum joint: 1 – base; 2 – linoleum; 3 – knife; 4 – metal ruler; 5 – mastic
Polyvinyl chloride linoleum on a heat and sound insulating base is kept indoors for a day at room temperature. Then it is rolled out along the base and kept in this state for 48 hours, after which it is cut along the perimeter. The carpet, cut to size, is smoothed from the middle to the edges and secured around the perimeter with a plinth so that the lower plane of the plinth presses it to the base, but at the same time does not impede its mobility when the temperature changes. The plinth is attached to walls and partitions.
The most common defects in coatings are the formation of bubbles, swelling, waviness, cracks, edge lag, and wear of individual areas. Bubbles appear when the thickness of the mastic exceeds 2 mm (dries slowly) or less than 0.5 mm. Bloating can occur as a result of poor smoothing (rolling) of linoleum. The swelling is eliminated by piercing it with an awl (the air is released), after which the area is smoothed with a hot iron and a weight is placed on it. You can spray hot mastic into the pierced area with a syringe and then smooth it out. If the entire surface of the linoleum is swollen, the coating is re-coated. Waviness is removed in the same way as bloating.
The deviation of the coating surface from the plane when checking with a two-meter control rod should not exceed 2 mm. Recesses between adjacent sheets are not allowed. The cracks are formed due to the fact that the linoleum was not kept in a warm room before gluing and shrunk. The edges peel off because the mastic was applied to a damp or dirty base. To eliminate this defect, the base is cleaned of dust and dried well, a more waterproof mastic is applied and the edges are pressed tightly.
Heavily worn areas are carefully cut out and the base is cleaned of old mastic. A new piece of linoleum, similar in color to the old one, is placed on the cut-out area. At one end, the insert is attached with small nails, and at the other, two layers of linoleum are cut - new and old. Thus, the insert is cut on all sides. After cutting, the base is smeared with mastic, the insert is placed, smoothed out and covered with a sheet of plywood, on which the load is placed. When laying linoleum on mastic, you must strictly follow the rules fire safety: It is forbidden to heat the mastic over a fire, use an open fire, and store the mastic in a closed container.
4. Installation of floors made of synthetic tiles
The installation of synthetic tile coverings is carried out in the following technological order: cleaning and leveling the base surface, priming the base surface, sorting tiles by size and selecting them by color, exchanging and dividing the floor axes of the room along the cord, laying out tiles without gluing according to the pattern and adjusting them to places adjacent to walls, partitions, etc., heating the tiles, applying mastic 0.8–1 mm thick and leveling it with a notched trowel, laying tiles on mastic with sealing the ends rubber mallet, installation of baseboards, cleaning with a rag soaked in solvent, places with protruding mastic, covering the floor with sawdust, heating the tiles only in winter time at room temperatures below 10 °C and when laying them on quick-hardening mastic.
The screed is cleaned with a metal scraper on a long handle, and dust is removed with a vacuum cleaner. industrial type. Depressions and unevenness on the screed are eliminated by smearing it with a polymer-cement composition using a spatula. The installation order is shown in Fig. 134.
Rice. 134. The order of laying tiles: a – toeing, sorting and laying out tiles in piles; b – applying mastic to the base; c – start of laying tiles; d, e, f – laying tiles
Rice. 135. Tile laying options
Floors made of colored polyvinyl chloride tiles with a smooth or embossed surface are laid according to a given pattern (Fig. 135) on a dry primed base. Grounds small rooms primed with a fly brush, and rooms with an area of more than 500 cm 2 - with a spray rod from the pressure tank compressed air. The tiles are brought into the room and kept until they acquire room temperature. After the primer layer has dried, the longitudinal and transverse axes of the premises are marked on it with a cord. From the point of their intersection, two rows of tiles are laid out perpendicular to each other, placing their edges against the axes (cords) and trying to lay a whole number of tiles along the length and width. If a whole number of tiles do not fit, the axes are shifted or the outermost tiles in the row are cut by one size. The tiles are laid parallel to the walls of the room, starting from the middle, since when the axes are divided, the point of their intersection is in the middle of the room.
When laying tiles at an angle of 45°, i.e. in a unfolded manner, the edges of the tiles are parallel to the diagonals of the room. When the tiles are arranged diagonally along the perimeter of the walls, a frieze is made, the width of which should be such that the main field of the frieze has halves of tiles of the same color along the entire perimeter.
To clarify the correct layout of the floor pattern, it is necessary to lay the tiles dry before gluing them. To do this, first place four tiles at the intersection of the axes, i.e. up, down, right and left from the center of the axes.
After this, the tiles are laid alternately close to one another on both sides of the previously laid four tiles along the length and width of the room; if a whole number of tiles do not fit, the axes are shifted.
Tiles are glued in two ways: on themselves and away from themselves. When laying on oneself, the worker moves as the tiles are glued and is always on the uncovered base; When laying away from oneself, the worker moves forward along the finished coating. When gluing PVC tiles, mastic is applied to the base or to the tiles. Quick-hardening mastic KN-2 is applied to the base (over an area of up to 2-3 m2, after which the tiles are carefully laid, ensuring the evenness of the laying and the selection of the pattern, as well as observing the permissible gaps. The mastic is poured from a bucket and leveled evenly over the base with a notched trowel. The thickness of the adhesive layer should not exceed 0.8 mm.
The worker takes the tile with his left hand and, holding it with both hands by the side edges, lays it carefully on the base against the cord or close to the previously laid tiles on the mastic and presses it tightly to the base. To ensure complete adhesion of the tile to the base, tap it with a rubber hammer. Excess mastic protruding from the seams is removed with a rag soaked in the solvent with which the mastic is prepared. After gluing, you cannot walk on the tiles for three days.
The main defects of tile coatings: tiles coming off, warping of edges, cracks in joints. The tiles come off because they were glued to a dusty or damp base. When repairing, lift the tile, clean the base from old mastic, dust, and if it is wet, dry it, after which new mastic is applied to this place and the tile is glued. In case of peeling of edges or corners, thick paper or thin cardboard is placed on the tile, smoothed with a hot iron, and then pressed down with a weight. Worn tiles are replaced with new ones as follows. The defective tile is removed, the base is cleaned of old mastic, a new tile is adjusted to the old location and laid on the mastic, after which a weight is placed on the tile for several hours. Recesses between adjacent tiles are not allowed.
Due to the fact that mastic contains harmful solvents, the rooms in which floors are laid should be well ventilated. Hot bitumen must be brought to the installation site in a closed container with a filling volume of no more than 75%.
Mastic can only be heated in hot water. Fire should not be used in mastic storage areas or when laying floors. Smoking is prohibited in the premises when laying floors.
Linoleum floors should be washed with warm and clean water, and if heavily soiled, with warm and slightly soapy water. It is not advisable to wash floors with soda, as soda causes linoleum to lose its shine and fade. Dirty stains that cannot be removed with hot water are removed with turpentine or chalk powder. On the surface of linoleum, matte spots disappear after rubbing it with turpentine mastics.
REPAIR OF JOINERY PRODUCTS AND STRUCTURES
Repair of window blocks. To repair window blocks, coniferous wood is used with a moisture content of 9 ± 3% for sashes, transoms, and vents, and 12 ± 3% for frames. IN window blocks For the most part, the bars of the boxes and individual bars of sashes, vents and, less often, the sashes as a whole fail. Individual bars of boxes are replaced with new ones, made exactly according to the profile and dimensions of the bars being replaced.
To replace the box block (Fig. 136, A) remove the doors from their hinges, and then remove the box from the opening. After replacing the block, the box around the perimeter is antiseptic and wrapped with roofing felt, after which it is reinserted into the opening, secured to the wall and the gaps are caulked. In separate boxes and bars, glue seals are inserted to replace damaged areas; glue seals are also placed in places where hinges are inserted.
If the entire block in the doors is damaged, it is replaced with a new one (Fig. 136, b), and if only part of the bar is damaged, then only this part is replaced. A new section of the block is connected to the remaining part of the block using spikes and glue. If the sash is skewed and the corner joints are loosened, the sash is straightened and angles are installed in the corners (Fig. 136, V) on screws.
Failed ebb tides are not repaired, but replaced with new ones (Fig. 136, G), installing them instead of the old ones using glue and screws or nails, having first cleared the installation site of old glue.
In box bars, the rotten part is replaced with a new one with a joint on spikes or a quarter joint with glue. In window sill boards, repairs are made by inserting a strip of glue (Fig. 136, d).
Door repair. In panel doors during operation, the lining peels off and the lining cracks at the hinge fastening points.
In places where the cladding has peeled off, it is lifted and cleaned of old glue. Then this place is coated with glue and the cladding is temporarily attached with nails or bars. After the glue has set, the nails or bars are removed.
In the places where the hinges are attached to the door frame, the unusable part is cut out and a new insert is placed on the glue. Until it sets completely, the insert is secured to the canvas with a clamp or nails.
Rice. 136. Repair of bindings, frames, window sills: a – frame repair – replacement of the lower part of the vertical bar; b – repair of the lower part of the sash, replacement of bars; c – fastening corners with squares; d – replacement of ebb on the outer sash; d – repairing a window sill by inserting a slats with glue.
To finish the surface of panel parts (boards, doors), an LM-3 paint-filling machine is used (Fig. 196). Using this machine, nitrocellulose and polyester varnishes and enamels based on these varnishes are applied to the panels. The paint-filling machine is a frame on which a conveyor for feeding panels, paint-feeding units and vertically adjustable heads, and a machine control panel are located.
The panels are placed on a conveyor, which evenly moves them under the heads, forming a varnish curtain. Passing through this curtain, the shields are coated with varnish.
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Control questions. 1. Tell us about the purpose of the lines included in the OK-250s kit. 2. What are the devices for processing logs for the walls of log houses intended for and how do they work? 3. How does the LM-3 paint filling machine work?
More on the topic § 78. Equipment for finishing carpentry and construction products:
- SURFACE FINISHING OF JOINERY PRODUCTS
- DESIGNS OF BASIC JOINERY PRODUCTS
- REPAIR OF JOINERY PRODUCTS AND STRUCTURES
- MECHANIZATION AND AUTOMATION OF PRODUCTION OF JOINERY PARTS AND PRODUCTS
- MANUFACTURE OF JOINERY PRODUCTS AND WOODEN STRUCTURES AT WOOD PROCESSING ENTERPRISES
6. Installation of built-in wardrobes
Built-in furniture (cabinets, mezzanines) is installed after laying the floors in the room, performing plastering and sanitary work.
Cabinets are assembled from ready-made elements on the floor. They are attached to the floor, ceiling, walls with nails, screws and bolts. The cabinet elements are attached to the walls using wooden plugs into which screws are screwed or nails are hammered. The cabinet elements are assembled together using bolts or screws.
The rigidity of the cabinet is ensured by the strong connection of the walls with the door blocks, as well as with the lower and upper parts of the cabinet (mezzanines, etc.). The cabinet elements are connected with bolts or screws only after checking the correct installation. The verticality of the installation is checked with a plumb line and a square.
In the closets, after they are installed, shelves or rods for dresses are installed in place. Types of connections for built-in wardrobe elements are shown in Fig. 126 a B C. The cabinet elements adjacent to the floor, i.e. the bottom of the cabinet, are covered with a plinth. The junction of the cabinet with the walls is finished with slats or platbands. Depending on the size, the gaps between the ceiling and the top of the cabinet are closed with a strip or a special cornice.
The shelf separating the mezzanine door from the cabinet door is attached tightly to the side walls of the cabinet, the remaining shelves are made removable, and the shelves are placed on under-shelf bars, metal or plastic shelf holders. To make cleaning the lower part of the cabinets easier, a polish is applied (Fig. 126, G).
Cabinet doors are hung on hinges or card hinges. Card hinges protrude from the outside of the door, so it is more advisable to use special hinges (Fig. 126, d, f).
Rice. 126. Connecting elements of built-in furniture: a – rear and side walls using a block; b – side wall with door block; c – rear wall with intermediate wall; d – details of the lower part of the cabinet; d – loop; e – hanging doors on hinges; 1 – side wall; 2 – screw; 3 – block; 4 – back wall made of particle boards; 5 – door frame block; 6 – door leaf; 7 – intermediate wall made of solid wood fiber boards; 8 – floor (bottom) made of plywood or hard fiberboard; 9 – floor boards; 10 – plinth; 11 – card loop, console, chrome-plated.
Handles are used to open cabinet doors. The cabinet doors are closed with latches consisting of an aluminum body and a latch mounted into it. The latch has a button for movement. Doors are hung so that they close tightly and do not spring when opening and closing. Door panels and other cabinet elements covered with valuable wood veneer are finished with varnish, and if the cabinet elements are made of plywood, solid fiberboard or particle boards without veneer, they are painted with nitro enamel or oil paint to match the walls. In some residential buildings, the surfaces of cabinets facing the room are covered with the same wallpaper as the walls, and the internal surfaces are covered with drying oil or oil or enamel paints.
On construction sites, cabinet elements have to be manufactured on site from particle boards 16 or 19 mm thick. In accordance with the working drawings, the dimensions of the cabinet elements - walls, doors, shelves - are applied to the sheet, after which they are cut out with a circular electric saw, hacksaw, etc. In those elements in which it is necessary to install wooden trim on the edges, select a groove on the edge of the plate, in which a wooden lining with a comb is inserted onto the glue. The lining of the shield elements is made flush with the plane of the shield.
SURFACE FINISHING OF JOINERY PRODUCTS
1. Types of wood finishing
Joinery products are finished with paints and varnishes that protect them from environmental influences. Painted products have a good appearance, are easier to keep clean, and their durability increases.
Types of finishing can be divided into the following main groups: transparent, opaque, imitation, etc.
With transparent finishing, the surface of the wood is covered with colorless finishing materials that preserve or further reveal the texture of the wood. It is used for finishing furniture and high-quality construction products: windows, doors, panels made from valuable wood.
Transparent finishes are achieved by varnishing, polishing, waxing and coating with transparent films. When finishing by varnishing, varnishes are used that contain film-forming substances in organic solvents, solvents, etc.
Most often, polyester, nitrocellulose and urea-formaldehyde varnishes are used for finishing wood, and less often - oil and alcohol varnishes. Nitrocellulose varnishes dry well, produce a transparent, elastic, durable and fairly weather-resistant film that can be sanded well. Varnishes based on urea-formaldehyde resins form a film with a shiny surface that is quite transparent. The film formed by oil varnishes is elastic, durable, weather-resistant, but not decorative enough; alcohol varnishes produce a film with insufficient strength, weather resistance, and low gloss. Depending on the degree of gloss, coatings are classified into glossy, semi-glossy and matte.
When waxing, i.e. applying a mixture of wax and volatile solvents (white spirit, turpentine) to the surface of wood, a transparent film is also obtained, formed by a thin layer of wax (volatile solvents evaporate during the drying process). The wax coating is usually applied to porous wood (oak, ash). The wax film is soft, so it is covered with an additional layer of alcohol varnish. The wax coating has a matte surface.
With an opaque finish, a film is created on the surface that covers the color and texture of the wood. Opaque finishes are used in the manufacture of school, kitchen, medical, built-in and children's furniture, doors, and windows.
To obtain an opaque coating, oil, nitrocellulose, alkyd, perchlorovinyl, water-based paints and enamels are used.
When painting with enamels with a large content of film-forming substances, glossy coatings are obtained, with a smaller amount - semi-gloss, and when painting with oil paints - matte.
Imitation finishing improves the appearance of products made from wood, the texture of which does not have a beautiful pattern. The main methods of imitation finishing are deep dyeing, pressing of textured paper with a pattern of precious wood, finishing with veneer, films, and sheet plastic.
Surface finishing using the airbrush method involves applying paint with an airbrush gun and creating a pattern (using a stencil). Using airbrushing, designs with planar (ornaments) and three-dimensional images can be applied to surfaces.
Lamination is one of the types of imitation finishing and consists of lining chipboard or fiberboard with paper impregnated with synthetic resins. When pressing boards covered with paper between metal spacers at a pressure of 2.5–3 MPa and a temperature of 140–145 °C, a smooth and shiny surface is obtained on the boards.
The performance qualities of paint and varnish coatings must have a number of physical and mechanical properties: adhesion to wood, hardness, heat, light and water resistance. These properties are of significant importance in the operating conditions of the products. They are determined by the quality of paints and varnishes, the conditions of their application, and drying of coatings.
Adhesion refers to the strength of adhesion of the paint coating to the surface of wood, while hardness refers to the resistance of the paint coating to the penetration of a harder body into it.
Water resistance is the ability of a coating to withstand the effects of water on the surface of a product. It plays a very significant role in the operation of carpentry products (window blocks, external doors) in conditions of variable humidity.
The purpose of finishing with painting and film materials is to give the surface of wood products ( wood materials) decorative look and protecting them from destruction under the influence of the external environment.
Depending on the operating conditions and purpose of the products, protective or decorative coverings. The finish is divided into transparent (in which the surface of the substrate is visible) and opaque. A special case of opaque finishing is imitation, in which the texture and color of different types of wood, as well as various patterns, are reproduced on the surface or coating being finished.
Requirements for the protective and decorative properties of coatings
The paint film of the coatings of joinery and construction products operating in atmospheric conditions must, first of all, have water and moisture permeability, preventing moisture deformations of the products when the ambient humidity changes. The durability of coatings, i.e. their ability to maintain specified properties, depends on their resistance to ultraviolet radiation, adhesion to wood and a number of other factors. Requirements for the finishing of joinery and construction products are determined by the regulatory and technical documentation for the products, as well as GOST 24404.
The optimal thickness of paint and varnish coatings on wood products should be at least 60-80 microns. Since the introduction of an antiseptic into the paint composition does not protect wood materials from damage by fungi when moisture penetrates through defective areas of the coating (or when the paint film is highly permeable), it is necessary to antisepticize the surface of the product itself. The roughness of the front surfaces in products for opaque finishing should be no more than (Rm max) 200 mm for front surfaces and 320 mm for non-facial surfaces; for transparent finishing Rm max) - 60-80 microns.
Surface preparation
Surface preparation includes bleaching, painting, filling, filling and priming.
Dyeing is the process of giving wood a new color or a uniform color background while preserving its texture using various dyes, pigments and mordants. The most common is surface dyeing, which uses mainly water-soluble synthetic dyes for wood from No. 1 to 16. The concentration of solutions is 2-5%.
Porosity filling is the treatment of the surface of ring-vascular wood species with viscous pore-filling compounds.
Puttying - (local and continuous) is performed to level the surface of the wood and mask dents, scratches, cracks, etc. The consistency of most putties is designed to be applied with a spatula. To better fill the unevenness of the substrate, the dry residue of putties should be higher than that of primers. When puttingtying products, especially those used in atmospheric conditions, it is necessary to avoid thick layers of putty (more than 0.3-0.5 mm), since during operation, shrinkage and cracking of the putty and, as a result, destruction of the coating are possible. Application of dyes, fillers and putties is carried out manually, by spraying, on roller and roller doctor machines MSh1.03, ShPShch
Dyeing and filling are used, as a rule, when finishing furniture.
Priming of wood and wood materials is carried out to improve the adhesion (adhesion) of the varnish (paint) coating layer to the substrate; reducing the consumption of more expensive coating paint composition; isolation of air, moisture and resins in the wood substrate, the release of which during application, drying and operation of the paint layer can lead to its destruction; increasing the conductivity of the surface of wood materials when painting in a high voltage electric field.
The primer can be applied using any mechanized method.
Primers differ from enamels and paints increased content pigment (filler) and, as a rule, the nature of the film former.
Due to the absence of white primers, when finishing joinery and construction products, enamels or paints are used as primers, and the use of drying oil is also allowed.
Drying paint coatings
Drying of paint and varnish coatings is carried out to harden the paint layer and can be carried out either only by evaporation of solvents (materials such as nitrocellulose, perchlorovinyl varnishes and enamels), or through chemical processes of oxidation, condensation and polymerization (materials such as oil, alkyd, urea, polyester varnishes and enamels etc.). The process of natural (air) drying at 18-20°C for most materials used is very long (more than 24 hours) and requires large production areas. Artificial drying is the most effective means of accelerating the process of coating formation.
Based on the method of supplying thermal energy, drying is divided into convection drying (heat transfer occurs through direct contact of the paint layer with circulating hot air); radiation (using irradiation of painted products with infrared and ultraviolet rays); due to the accumulated heat of a product preheated by convection, thermo-radiation or contact methods; curing of the gelatinized paint layer in presses or by rolling with heated rollers.
By design, drying chambers can be divided into two main types: dead-end periodic and continuous through. The former are used in enterprises with small-scale production.
One of the promising methods for drying paints and varnishes is curing under the influence of UV radiation (photochemical drying method). In this case, curing is carried out due to the conversion of UV radiation into thermal radiation in the paint layer itself, which significantly reduces energy losses and heating of the substrate. The optimal wavelength of UV radiation is 0.200-0.360 microns. The photosensitivity of paint compositions is achieved by introducing photoinitiators into them - a photosensitive additive, the most effective of which are methyl and isobutyl ethers of benzoin, grigonal-14, etc.
UV curing is used to transparent coatings, mainly polyester. However, the successful experience of using the photochemical method of drying pigmented compositions abroad and similar attempts by our scientists create the prerequisites for expanding the scope of its application.
Drying by pre-heat accumulation
This drying method combines the advantages of thermoradiation curing (film formation begins from the substrate) and eliminates blistering of the coating due to moisture and air contained in the wood substrate. The method is effective for coating thicknesses up to 80 microns. The degree and duration of heating depends on the type paint and varnish material and masses of details. For quick-drying paint compositions (urea, water-dispersion), surface heating of the parts for 40-90 s at a heating element temperature of 300-400°C or air temperature of 170-180°C is sufficient. When painting with enamels, the heating time increases to 2-5 minutes. After paint application, stabilization (also called degassing or normalization) is required in ventilated, unheated chambers, where the solvent is removed from the hardening paint layer.
Convection drying
Steam and electric heaters are used to heat the circulating air in drying chambers. Practice shows that when heating air to 60-80°C, steam heaters are economically preferable. The direction of air flow in walk-through drying chambers is the opposite to the movement of the conveyor with painted parts.
Thermoradiation drying
During thermoradiation drying with infrared radiation (thermoradiation), heat is transferred to the paint layer mainly from the substrate, which is heated by absorbing infrared rays. Heated from below, the paint layer does not interfere with the removal of solvents, which significantly speeds up the curing process compared to convection drying. When thermoradiation drying of paint compositions on wood, the release of moisture, air and resins contained in the substrate, as well as warping of products at high temperatures, should be taken into account. At a temperature on the surface of products of 130°C and a humidity of coniferous wood of 14-15%, the critical duration of drying by thermoradiation is approximately 2 minutes: during this time, the resin in the wood does not have time to melt. However, this time is not enough to cure most of the paint compositions used. This determines the upper limit of the wood surface temperature during thermoradiation drying, equal to 60-80°C.
As sources infrared radiation Lamp, panel and tube emitters are used. The disadvantage of lamp emitters is their low efficiency. and short service life. A panel radiator, which is a cast iron or ceramic plate with heaters built into it (or a heated gas burners), produces a uniformly distributed radiation flux, but has a high inertia. The most common are tubular electric heaters (TEH) with aluminum reflectors НВС (GOST 13268) with operating temperature heater surface up to 450°C.
During thermoradiation drying of lattice-shaped products (for example, window blocks), the energy of the emitters is not fully used. Practice shows that the use of combined (thermoradiation-convection) drying for painted products complex shape is impractical, since the duration of curing of the paint layer by thermoradiation is not sufficient for convection drying of the internal (shielded from radiation) areas of the painted surface washed by hot air. The energy intensity of an electric-thermoradiation drying chamber is significantly higher than that of a convection drying chamber.
The book contains reference materials related to the manufacture and installation of joinery and construction products and the production of household furniture. Information is provided about wood and other materials used, about machines, tools and devices, technology and organization of production, safety precautions, as well as some regulatory data. The reference book is intended for carpenters and technical personnel working in the furniture and construction industries.
Preface
Section I. Carpentry and construction products and furniture
Chapter I. Joinery and construction products
1. Windows
2. Doors
3. Carpentry partitions, panels and vestibules
4. Parquet floors
5. Joiner's rods
6. Built-in building equipment
Chapter II. Furniture
1. Types of furniture
2. Household furniture
3. Sets and sets of household furniture
4. Special furniture
Section II. Materials
Chapter III. Basic information about wood
1. Wood structure and tree species
2. Technical properties of wood
3. Wood defects
Chapter IV. Timber
1. Lumber
2. Planed materials and semi-finished products
3. Plywood
4. Joiner boards
5. Fiberboard and particleboard
Chapter V. Drying wood
1. Drying methods
2. Allowances for shrinkage
3. Drying chambers
4. Drying modes
5. Drying with high frequency currents
Chapter VI. Adhesives
1. Basic properties of glue
2. Types of adhesives
Chapter VII. Auxiliary materials and accessories
1. Metal fastenings
2. Window and door devices
3. Furniture fittings
4. Springs
5. Padding and wallpaper materials
Chapter VIII. Finishing materials and compositions
1. Materials for paint and varnish compositions
2. Dye compositions for transparent wood finishing
3. Compositions for opaque wood finishing
4. Primers and putties
5. Varnishes and polishes
6. Auxiliary materials
Section III. Machines, tools and devices for wood processing
Chapter IX. Wood cutting
1. Basic wood cutting processes
2. Wood processing methods
Chapter X. Cutting tools for woodworking
1. Types of cutting tools
2. Machine tool
3. Powered and hand tools
4. Abrasive tool
5. Files
6. Auxiliary tool
Chapter XI. Woodworking machinery
1. Types of woodworking machines and their parts
2. Basic parameters of machines
3. Sawing machines
4. Planing machines
6. Drilling and slotting machines
7. Combined and universal machines
Chapter XII. Powered and hand tools
1. Power tool
2. Hand tool and accessories
Eyes XIII. Machines and equipment for sharpening and adjusting cutting tools
1. Sharpening machines
2. Soldering and straightening machines
Chapter XIV. Machines and devices for gluing, assembly and finishing
1. Gluing equipment and glue-spreading machines
2. Presses, assembly machines and fixtures
3. Grinding machines
4. Apparatus and accessories for painting and polishing
Chapter XV. Setting up and maintaining machines
1. Accuracy of processing on machines and their settings
2. Improving the quality of parts processing
3. Basic rules for caring for machines
Section IV. Joinery technology
Chapter XVI. Joinery design
1. Main types of joinery joints
2. Formation of parts and assemblies
3. Connections of parts and assemblies of main furniture products
4. Drawing up working drawings and marking connections
5. Technical specifications for carpentry and construction products and household furniture
6. Tolerances and landings in woodworking
Chapter XVII. Mechanized furniture production
1. Stages of product manufacturing
2. Mechanized procurement and processing of parts
3. Gluing and veneering
4. Assembly of parts and assemblies
5. Product assembly
Chapter XVIII. Product finishing
1. Types of finishing
2. Preparation for finishing
3. Painting and matte finish
4. Varnishing and polishing
5. Mechanization of processes and finishing modes
6. Artistic finishing
7. Installation of accessories
Chapter XIX. Manufacturing and installation of joinery and construction products
1. Manufacturing of joinery and construction products
2. Preparation of elements of carpentry rods, partitions, panels and built-in equipment
3. Installation of joinery and construction parts
4. Finishing walls and ceilings with valuable wood species
5. Installation of window frames and doors made of valuable wood
6. Laying artistic parquet
Section V. Organization of carpentry production
Chapter XX. Organization of production
1. Types of carpentry production
2. Technological regime and standards for carpentry and mechanical production
3. Calculation of the productivity of main technological equipment
Chapter XXI. Labor organization and technical regulation
1. Labor organization and qualification characteristics carpenters
2. Workplace carpenter
3. Safety precautions
4. Norms and prices
Chapter XXII. Technical and economic indicators and documentation for joinery and furniture production
1. Technical and economic indicators
2. Technical documentation
3. Drawing up specifications
Literature
Subject index
Applications
