RU2120854C1 - Method of manufacturing end-face decorative panels - Google Patents

Abstract

FIELD: wood-working. SUBSTANCE: method includes molding of timber blanks by method of contour pressing into shaped molds such as regular polygons with compression of rounded blocks over entire length prior to press-fitting into mold. Blanks are dried in the same molds. This done, blanks are calibrated and glued into stacks which are compressed along three mutually perpendicular axes by keeping them under pressure. Then stacks are sawed into plates which are cut into separate elements. They are glued on base, thus obtaining, decorative picture after finishing operations are carried out. EFFECT: enhanced efficiency of process, higher hardness and wear-resistance of material. 6 dwg

Description

 The invention relates to woodworking and can be used in the manufacture of raw wood, which is predominantly wood waste, end decorative panels for the artistic cladding of walls of internal premises, furniture and other products or their individual parts, as well as for the manufacture of parquet boards.

 A known method of manufacturing decorative products, such as wall panels and parquet panels (Fedorov V.I., Kanevsky E.M., Kolgina II, etc. - 1000 tips for saving in everyday life. - 2nd ed. Stereotype. - M .: Economics, 1991.- p. 166-168). The method includes manufacturing lattices with square or rectangular cells from articulated rails; the production by the method of planing or sawing from dried wood waste of checkers, the length and width of which corresponds to the size of the cells, and the thickness to the height of the rails; gluing the grating to the base; gluing checkers into grid cells; drying the shield and processing it with sandpaper.

 The disadvantage of this method is its low productivity associated with the method of manufacturing checkers and the need for manual dialing to create the desired composition.

 In addition, the resulting composition is heterogeneous and does not have the unity of style, since it is a combination of checkers with a longitudinal and end cut, separated by slats with a longitudinal cut of wood.

A known method of manufacturing end furniture tiles according to the patent of the Russian Federation N 2001749 (IPC ⁶ B 27 M 3/04, publ. 30.10.93), including the shaping of the bars by cutting them from wood waste, calibration of the bars, their connection in the boards, exposure boards with 22 - 24 ^o C, calibrating the boards by thickness, cold gluing the boards into blocks, sawing the blocks into plates, sampling the material in the areas of the corner joints of the plate elements to form holes, installing wooden plugs in the obtained holes for gluing, holding for gluing, sampling material at the seams of the connection of the elements of the plates also before the formation of holes; installation in the latter of wooden plugs on glue.

 Moreover, the holes in the samples of the material in the plate can be made in the form of a circle, rectangle, triangle, hexagon or octagon, and the cross section of the bars themselves can be made in the form of a polygon. For the manufacture of bars and corks can be used wood of various species.

 The specified method has insufficient productivity, which is due to the shaping of the bars by the cutting method, and the increased complexity of the operations of selecting holes in the zones of corner joints and at the joints of the joints, making plugs and pasting them into these holes. Another disadvantage is that the hardness and wear resistance of the product depend solely on the physical properties of the wood used. In addition, on the front surface of the panel, different-sized corks reduce the decorative and artistic advantages of products, unnecessarily complicating the composition of the picture.

There is also a method of manufacturing decorative plates from wood material according to the patent of the Russian Federation N 2062230 (IPC ⁶ B 27 M 3/04, 1996). This method includes:
- manufacture of churak from wood material;
- sawing out from churaks bars;
- shaping of the workpieces by sawing them out from the bars.

In this case, the blanks are cut along the longitudinal fibers of the wood of the churaks. The cross section of each workpiece is made in the form of a regular polygon. The cross section of each workpiece is smaller than the longitudinal. The operations of sawing out bars from churaks, cutting them into blanks and preliminary calibration are performed in a single technological method;
- a set of blanks in a package of at least four blanks joined along long longitudinal faces;
- gluing the package with a tight compression in the conductor;
- cutting (sawing) the package in the transverse direction into plates, as a result of which the first stage of final calibration is carried out and decorative plates are obtained, the front surface of which is formed by the end faces of the wood material;
- grinding at least one surface of the decorative plate, which is the second stage of the final calibration.

In addition, the method may include:
- additional grinding of the second surface of the plate;
- laying the blanks in a bag either with a churak butt in one direction, or in a checkerboard pattern with alternating on one end face of the butt and the top of the churak;
- additional processing of the longitudinal surface of the package before cutting it to give the decorative plate a predetermined profile;
- the implementation of the cross section of the workpiece in the form of various regular figures: a triangle, square or hexagon;
- getting churaks from trunks and branches with a ratio of their length to the average diameter of at least eight;
- the implementation of the square of one row offset relative to the square of the adjacent row to half the length of the side of the square.

 The method according to the patent of the Russian Federation N 2062230 is the analogue closest to the invention in terms of essential features.

Signs of an analogue common with the essential features of the invention are:
- preparation of churak from wood material;
- forming blanks with a cross section in the form of a regular polygon;
- connection of the blanks in the package by gluing them along the longitudinal faces with subsequent compression of the package;
- sawing the package into plates;
- calibration of blanks.

 The method according to patent N 2062230 is not sufficiently productive, which is associated with the production of bars from churak and blanks from bars by the method of cutting (sawing). Inadequate are measures to improve the performance of panels; their hardness and wear resistance mainly depend on the properties of the wood used.

 The problem to which the invention is directed, is to increase the productivity of the process, improving the operational and decorative-artistic qualities of the panels.

 When implementing the invention, the following technical results are achieved: increasing the productivity of the process, giving the workpiece material new qualities - increased hardness and wear resistance, preventing the formation of cracks and delaminations on the workpiece during the manufacturing process, correcting and stabilizing the shape of the workpieces, gapless connection of the workpieces in the bag.

 The essence of the invention lies in the fact that in the method of manufacturing the end decorative panel, including the preparation of churak from wood material, forming blanks with a cross section in the form of a regular polygon, joining the blanks into a bag by gluing them along the longitudinal edges, followed by crimping the bag, sawing the bag into plates and calibration of the blanks and plates, shaping of the blanks is carried out by contour pressing.

 In this case, contour pressing means the process of compaction of wood as a result of forcing a rounded churak through a forming element (mold with a die) under the influence of a working tool (pusher, punch). In the proposed method, the pressing is carried out in profile forms - dies having the form of regular polygons.

 Immediately before the rounded churak is pressed through the die, it is compressed along its entire length; compression and pressing occur in one working stroke of the pusher. After pressing, the obtained preforms are dried in the same molds.

 When gluing blanks into packages, they are squeezed along three mutually perpendicular axes by holding the packages under pressure, providing a gap-free connection of the bars and correcting their geometric shape. After sawing the package into plates, format cutting of the plates into elements is carried out, which are then glued to the base to obtain a decorative pattern.

 Distinctive features of the proposed method are the shaping of blanks by contour pressing into shaped forms; compression of rounded churaks along their entire length before shaping; subsequent drying of the blanks in the same forms; squeezing the glued bag along three mutually perpendicular axes by holding it under pressure, and after sawing the bag - format cutting plates on the elements, which are then glued to the base to obtain a decorative pattern.

The essence of the proposed method is illustrated by drawings, which depict:
in FIG. 1 - blank in the form of a hexagonal prism;
in FIG. 2 - a fragment of a package made of hexagonal blanks;
in FIG. 3 is a fragment of a plate obtained by cutting a package made of hexagonal blanks;
in FIG. 4 and 5 - elements obtained as a result of format cutting plates.

 In addition, in FIG. 6 additionally shows a photograph of a countertop made from panels obtained by the proposed method.

 The proposed method involves the use of raw wood waste with a diameter of 50 - 150 mm: whips, apices, thick branches, hulling waste, etc. It is preferable to use soft hardwood and coniferous wood: linden, alder, pine, spruce, birch, although they can be used and harder species such as oak, ash, maple, etc.

The method consists of the following sequential operations:
1. Cutting wood into churaks of the required length, equal to the sum of the length of the finished bar and the allowance of 5 - 7 mm for machining the ends.

 2. Pre-calibration - cylindering (rounding) of churaks, ie giving them a cylindrical shape with a diameter, the value of which is due to the permissible degree of compression of the wood and the concentration of equipment for pressing. For example, if you want to get a hexagonal workpiece with inscribed circle diameters of 35, 50, 70 and 100 mm, then in this operation the churaks are machined to diameters of 50, 70, 90 and 130 mm, respectively.

 3. Forming in order to obtain blanks in the form of regular polyhedral (square, hexagonal or octagonal) prisms from rounded churak.

 The blanks are formed in two stages: preliminary compression of rounded churaks and pressing. Both stages are carried out on a press capable of creating the necessary axial force and provide the required stroke. The press is equipped with a multi-place mold. The number of places in the mold, i.e. the number of simultaneous pressed blanks is determined by the size of churak, the properties of the wood used for them, the amount of force developed by the existing press, the productivity of drying equipment, etc. Both stages are performed in one stroke of the working tool - the pusher mounted on the movable part of the press.

 To compress the churak along its entire length, it is advanced through the pusher through a crimping sleeve with an internal stepped cylindrical hole. In this case, the diameter of the churak is reduced by 6 - 10%. Preliminary compression provides easier entry of churak into the inlet part of the profile form and improves the quality of pressing by preventing the formation of cracks in the workpiece and peeling of wood on it.

 With further working stroke of the pusher, the churak is pressed through a square, 6- or 8-angled die in a profile shape. The working surface of the die is made in the form of an inverse cone, turning into a multifaceted prism corresponding to the desired profile of the finished workpiece.

 Pressing parameters depend on the type of wood and the required size of the workpiece. So, if softwood is used, then to obtain a six-sided workpiece with an inscribed circle diameter (turnkey size) equal to 50 mm, an axial force of 4 to 5 tons is applied to each workpiece, and pressing is carried out at a speed of 15-50 mm / s depending on the type of wood. If it is necessary to obtain a workpiece with a specified size of 100 mm, then the axial force on each workpiece is at least 10 - 12 tons. When using maple or birch, the axial force is increased by 20%.

 When designing molds, it is assumed that the degree of compaction of wood should be at least 40%; in the process of pressing, wood juice is removed from the billet.

 Significant pressing speed, simultaneous production of all lateral surfaces of the workpiece, multi-location of the mold provide an increase in process productivity compared to the method of obtaining workpieces by milling or sawing 3-4 times. In addition, the compaction of wood during the pressing process in 1.5 - 1.8 times gives it new qualities - increased hardness and wear resistance, i.e. softwood wood is close to hardwood in its properties.

4. Drying the workpieces. Molds with pressed blanks are loaded into a steam or electric drying chamber with forced moisture removal. The billet is dried to achieve a wood moisture content of 6-8%. Drying parameters are selected depending on the type of wood, its initial moisture content and the size of the workpieces. Drying in the mold determines giving the preform the necessary shape and its stabilization, protects the preform from possible cracking, and allows for more stringent drying modes. The temperature in the chamber is 70 - 120 ^o C, and at 70 ^o C the drying time depending on the type of wood is from 15 to 45 hours, and at 120 ^o C - from 5 to 8 hours.

 5. The final calibration of the workpieces is carried out in order to ensure the accuracy of their sizes of not more than ± 0.1 - 0.2 mm.

 Calibration is carried out on a milling or horizontal grinding machine with a replaceable mill.

 6. The trimming of the blanks is aimed at obtaining blanks of the same length equal to 95-100 mm. In addition, it allows you to open at the ends of the blanks wood defects: the presence of black knots and rot. Trimming is performed on the trimming machine.

 7. Sorting for the purpose of rejecting defective blanks, as well as, if necessary, selecting blanks by structure, shades, etc.

 8. Bonding blanks in bags.

Environmentally friendly glue, for example, polyvinyl acetate emulsion (PVA), is applied to the side surfaces of the blanks using an applicator, and a set of predefined sizes is made up of blanks (Fig. 2). The assembled bag is placed in a hydroficated collar with hydraulic clamping devices, with the help of which a comprehensive compression of the bag is carried out along three mutually perpendicular axes. Bonding is carried out under pressure, providing a gap-free connection of the workpieces and the correction of their geometric shape, which is 35 - 40 atm. Under this pressure, the bags are compressed during the time necessary for the polymerization of the adhesive: 20-30 minutes at 20 ^o C or 8-10 minutes at 50 - 70 ^o C.

 Due to the application of the specified pressure and endurance, any errors in the shape of the workpieces are corrected, and gaps between the workpieces are eliminated in the package. The bag can be assembled from blanks with the same or with different cross-sections, as shown in FIG. 5.

 9. Cutting into plates. The package is cut into plates (Fig. 3) on a cutting machine equipped with devices providing the required plate thickness and having a feed and return system. Plate thickness 2 - 5 mm. To ensure a minimum amount of waste, it is necessary to use a band saw, which allows you to get a cut width of 1.2 - 1.5 mm, while a circular saw gives a cut with a width of 4 - 5 mm.

10. Format cutting plates. The plates are cut on a cutting machine for format cutting into elements of shapes and sizes necessary for subsequent work, for example, squares with a side of 150 mm, rectangles 150 x 250 mm, rhombuses with a width of 150 mm and an angle at one of the vertices equal to 60 ^o , etc. . (Fig. 4 and 5).

11. Sticker panels. The resulting elements are used for sticker panels designed for facing rooms and furniture or for the manufacture of parquet boards. The design, shape, size and processing types of panels are selected depending on their purpose. In the general case, the plates are glued onto a solid base of the required thickness — plywood, wood-particle board (particleboard), wood-fiber board (fiberboard), cement-bonded particleboard (DSP), MDF-plate, etc. When gluing, adhesive that does not contain water. The panels are obtained, for example, in the form of a square 600 x 600 mm, a rhombus 630 mm wide or a rectangle of the desired size. Gluing to the base is carried out in a shaft with lateral compression, which is placed in a press, providing a specific pressure of at least 1 kg / cm ² . The exposure time in the press is determined by the instructions for the use of the used brand of glue and the temperature of the heating plates of the press.

 12. Grinding the panels. It is produced on a two- or three-drum grinding and calibration machine in order to process the front surface of the panel to the required roughness indicators and calibrate the panel by thickness. Grinding is carried out with an abrasive belt of two or three different degrees of granularity. In this case, the panel is fed into the working area of the machine and its front surface is sequentially treated with an abrasive tape of coarse, medium and fine grain size. The machine is adjusted so that after grinding the panel thickness will be equal to the required.

 13. Coating and drying the panel. At least 3 to 4 layers of moisture-proof colorless (or tinting) environmentally friendly varnish are applied to the front surface of the panel. The drying parameters of each layer are selected in accordance with the instructions for use of this varnish.

 Consider an example implementation of the method in relation to the manufacture of panels from blanks in the form of a hexagonal prism with an inscribed circle diameter of 50 mm and a length of 100 mm. The material is pine.

 From wood waste, churaks 105 mm long are cut using a saw device equipped with a device for portioning the cut material. Then churak give a cylindrical shape with a diameter of 70 mm. Cylindering is performed on a punching machine with a hydraulic drive for feeding churak and with a working tool in the form of a conical knife. The required force does not exceed 1 tf. Machine productivity not less than 5 - 6 churak per minute.

 Then, the shaping operation is performed on a hydraulic press having an axial force of at least 100 tf and a stroke of at least 600 mm. In the process of forming, first the rounded churk is subjected to preliminary compression along its entire length, as a result of which its diameter is reduced to 65 mm. Then, the pressed churak is pressed through a special die into a profile shape in the form of a hexagonal prism with an inscribed circle diameter of 53 mm. In this case, the degree of compaction of wood is 40%, the pressing speed of 15 - 20 mm / s, the pressing force is 4 ton-force per workpiece.

Next, the pressed blanks together with the mold are loaded from the drying chamber, where they are kept until the humidity is 6 - 8%. Drying time at 70 - 80 ^o C 15 - 18 hours before the blanks fall out of the mold.

 After drying, the workpieces are calibrated, after which their cross section takes the form of a regular hexagon with an inscribed circle diameter of 50 ± 0.1 mm.

 To obtain blanks of the same length, the ends are machined, maintaining a size of 90 ± 0.3 mm.

 Then the blanks are sorted by the visual method with the rejection of defective parts, as well as the selection of blanks with similar structure and shades.

After this, the blanks are glued into bags, for which PVA glue is applied to the longitudinal side surfaces of the blanks, a bag of 650 x 670 mm is assembled from the blanks, the bag is placed in a collar and it is fully compressed with a specific pressure of 35-40 atm for 20-30 minutes at 18 - 20 ^o C.

 After the polymerization of the adhesive, the packages are cut into plates with a thickness of 2 - 5 mm on a band saw with a cutting width of 1.2 mm.

 Next, the plates are cut into 150 x 150 mm squares on a cutting machine for format cutting.

Then the base is prepared from plywood in the form of a square of 600 x 600 mm, applied to the base and on the elements in the form of squares of 150 x 150 mm, water-containing adhesive KS-1 and assembled on the glue of the panel to obtain a decorative pattern. The panels are placed in a press, with the help of which a pressure of 1.5 - 2 kg / cm ² is held for 30 to 40 minutes.

 After the specified exposure proceed to finishing operations. The panel is ground on a three-drum grinding and calibration machine, each of the successively arranged drums of which is equipped with an abrasive belt of different degrees of granularity. By such a treatment, the surface finish of the front layer of the panel is not worse than 30-40 microns. In this case, the machine is adjusted so that after grinding is completed, the panel thickness is 21 ± 0.2 mm.

 Then, if necessary, format cutting of the panels is carried out, giving them the necessary dimensions.

 In conclusion, from the front surface of the panel apply from 3 to 5 layers of moisture-proof colorless varnish with drying after each application of the layer.

Thus, the implementation of the invention allows to obtain a technical result, which consists in:
to increase the productivity of the process, to give the panel material new qualities - increased hardness and wear resistance due to the shaping of workpieces by contour pressing;
in preventing the formation of cracks and delaminations on the workpiece due to its preliminary compression;
in the stabilization of the shape of the blanks - due to their drying in the molds;
in providing a clearance-free connection of the workpieces in bags and correcting the shape of the workpieces by compressing the workpieces with an adhesive layer deposited on them in packages along three mutually perpendicular axes.

Claims (1)

 A method of manufacturing an end decorative panel, including the preparation of churak from wood material, shaping blanks with a cross section in the form of a regular polygon, joining blanks into a bag by gluing them along the longitudinal edges, followed by compressing the bag, sawing the bag into plates, calibrating the blanks, characterized in that before shaping, rounded churacs are compressed along their entire length, the blanks are shaped by contour pressing in shaped molds x followed by drying preforms in these forms, the compression adherend package produced in three mutually perpendicular axes by holding under pressure, and after the package on the sawing plate produced in the latter format cutting elements, which are then glued to a substrate to give a decorative pattern.

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