JPS60180835A - Method of molding decorative flitch - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] This invention specifically uses a resin board containing a large amount of wood powder as a backing material for decorative veneer, and aims to improve the water resistance properties, etc., which have been found to be inferior to ordinary plywood materials. In addition, an object of the disclosure is to easily and inexpensively provide a plywood material having an appropriately uneven decorative surface.

Therefore, conventional molded products with natural wood veneers on their surfaces were generally based on plywood made by laminating veneers together, and in some molded products, It was found that a veneer was laminated onto a copper-silver or resin board.

However, in all of these cases, most of the molded products are plate-shaped, and some of the molded products are made to have a rounded surface as part of the end surface treatment. Even in this case, the veneer was simply pasted along the rounded surface formed on the core material.

In addition, when molding plywood, when using a material other than wood, especially a synthetic resin board as the core material, problems such as expansion/contraction and distortion due to thermal changes in the material and moisture content may occur. Problems such as expansion/contraction and distortion occur in the overlapping materials due to changes in
This is said to be a cause of distortion in the molded plywood or peeling of the bonded surfaces, and also a cause of cracks in the bonded veneers.

In view of the disadvantages of conventional plywood, the method for forming decorative plywood according to the present invention uses a resin board containing a large amount of wood powder as the core material on which the veneers are laminated, and improves its material characteristics. A sheet material with elasticity such as cheesecloth between the veneer and the resin board to be overlapped, which is made to approximate the material characteristics of the veneers that are overlapped as much as possible, and also avoids the inconveniences of wood boards. This interposition effectively absorbs differences in expansion/contraction and shrinkage rates between the laminated materials, as well as the strain caused by mutual shearing of the materials at the time of warping, and prevents the peeling of the laminated decorative veneers. This effectively prevents inconveniences such as cracking.

In addition, by interposing a flexible sheet material, it is possible to perform the press forming described below, and it is possible to create uneven patterns or shapes as appropriate without causing any twisting or cutting of the bonded veneer surfaces. The molding of decorative plywood that has a shape makes it possible to form it.

The method for forming decorative plywood according to the present invention, in order to achieve effective lighting properties, is particularly characterized by mixing 20 to BOwt+% of cellulose-based fine powder into a synthetic resin material and heating-molding it. 100 to 14 for resin molded products made by
Along with this reheating treatment within a temperature range of 0°C, a veneer is attached via a stretchable sheet material, and the veneer is pressed and molded from the surface of the attached veneer to the surface of the resin molded object. Based on the point of lamination and integration, a molding method is planned using the following specific examples and considerable equivalent means accompanying these examples.

Hereinafter, a typical embodiment of the decorative plywood according to the present invention will be described with reference to the attached drawings.
2) shows a synthetic resin board for tensioning the veneer (1), and (3) shows typical cheesecloth as a stretchable and flexible fabric.
(4) shows a preheating device for the plate (2), and (5) shows a pressing device.

Therefore, the veneer (1) used is prepared as a thin board of 1 to 4 m + *, which is provided as a rotary lace, veneer saw, or slicer, depending on the decorative purpose, using wood with various characteristics according to the purpose. It is what was done.

Next, the plate (2) to be used was created and prepared using the following various methods. That is, 100-150
Cellulose-based aggregates such as crushed mesh chips, pulp, and rice husks that have been made into fine powder are thoroughly dried to a moisture content of 3 to 5%, and then added to a resin material with a moisture content of 20 to 5%.
A plate-shaped primary foamed or non-foamed resin board (2) is obtained by mixing with or without a foaming agent within the range of wt% and sufficiently kneading and heating. .

In addition, this cellulose-based aggregate is planned to be used in two cases: one in which the cellulose-based aggregate is mixed as is, and the other in which the aggregate itself is subjected to considerable pretreatment by the method described below. It is something.

In addition, the foaming material to be mixed must be a highly volatile material such as butane, pentane, or hexane, which does not dissolve the material resin in any way, or materials such as soda carbonate or calcium carbonate. It was planned.

Furthermore, as the molding means for obtaining the primary foamed or non-foamed resin board (2), kneading using heated rolls and hot pressing are usually planned, but the aggregate itself to be mixed must be sufficiently neutralized. , in case of hardening treatment,
A separate plan was to supply plate materials by cutting and developing extruded tube materials using a general extruder.

In addition, the resin materials to be used are not limited to thermoplastic resins such as vinyl chloride resin, ABS resin, polycarpo resin, and polystyrene resin, but it is also planned to use thermosetting resins such as phenol resin and urea resin. be.

A cheesecloth (3) is attached to the surface of the board (2) thus provided, and a veneer (1) is further attached to the top surface of the cheesecloth (3), and this is heated to around 30°C. The cooling molding is performed by pressing with a press to create an appropriate uneven pattern on the plate (2) and at the same time to ensure that the plate (2) and the plate (1) are bonded together as one piece.

In addition, in order to make the adhesion between the plates (1) and (2) more effective, it is possible to interpose an appropriate resin adhesive on the overlapping surfaces of the plates (1) and (2). In particular, the interposition and use of this adhesive was planned in accordance with the characteristics of the resin as the constituent material of the plate (2).

Next, in the case where the board (2) is a foamed board, secondary foaming of the board (2) is promoted in this reheating and press treatment process, and the desired molded plywood having a good molding surface is obtained. was particularly obtained.

In addition, to explain a more typical molding method for the resin plate (2) that becomes the ridge core material, first, the materials to be prepared, such as thermoplastic resin materials such as vinyl chloride, ABS resin, and polystyrene, and wood. It consists of a powder-based mixed aggregate, calcium carbonate powder, a hardening agent, a stabilizer, a coloring agent, etc., which are added as necessary.

The thermoplastic resin material to be used is determined based on the selection criteria that satisfies the various needs required for molded articles.
In building materials, fitting materials, etc., vinyl chloride resin is generally the most commonly used resin due to its molding properties, appropriate strength and hardness of molded products.

The aggregate used was then neutralized using the following procedure. That is, a cellulosic material such as crushed chip material, pulp material, or rice husk is prepared and subjected to a drying process, especially a heat drying process, to reduce the moisture content of the material to 15%.
It has been pre-processed so that it is within As the moisture content in the material decreases to within 15%, the visible drying process rapidly induces a phenomenon of destruction of the constituent fiber structure of the material, resulting in the crushed chip material becoming rough bundles or lumps of cellulose. In addition, the structure of the cellulose in pulp material and rice husk is certainly destroyed, and the cellulose is separated.

An emulsion-type urea resin adhesive is applied to the material, which is visibly dry and whose structure has disintegrated.
By leaving it for 20 to 30 minutes, this urea-based resin adhesive liquid is sufficiently impregnated into the material, and its pH value is usually about 5.

Incidentally, attempts have been made to further adjust the pH value of the material toward neutrality by separately adding ammonia chloride or hydrochloric acid as a hardening agent to this resin adhesive liquid, as necessary.

In this way, the material impregnated with the urea-based resin liquid and cured is subjected to heat drying at a temperature of 100 to 150°C and crushing into powder in the next step. The water content is within 3 to 5%, as close to ot as possible, and the particle size is about 100 to 150 mesh.

During such heat drying and crushing, the P)l value of the material itself is within the range of 6 to 7, and is adjusted to be approximately neutral.

The neutralization treatment of the acidic material at the starting point is largely dependent on the action of the urea-based resin adhesive that is interposed during the process, and the addition of the urea-based resin adhesive is necessary. In unplanned simple heating and drying treatment of cellulose-based materials, the pH of the starting material is 5, whereas the pH of the final material, which has been made into a dry fine powder, is 2 to 3, and conversely, the pH value becomes acidic. It is tilted. On the other hand, by interposing a urea-based resin adhesive, the material of P) 15 is neutralized while gradually releasing the acetic acid contained in the material as wood acid gas as it is heated and dried. The P)l of the material was adjusted to be within the neutral range of 6 to 7.

The aggregate thus provided is heated during processing to reduce the moisture content in the aggregate to a maximum of 13%, ideally 3 to 5%, and as much as possible to O2. In resin molding with mixed aggregate, there is no room for water vapor to be generated, and the dissociation and volatilization of the wood acid contained in it are prevented, eliminating the possibility for acid gas to be generated. 6 to 7.

In the aggregate thus provided, the wood acid contained in the wood powder, especially acetic acid gas, evaporates during impregnation and heat molding with a thermosetting resin material mainly consisting of the above-mentioned urea resin. This effectively reduces the possibility of acid gases being generated from the aggregate used in the subsequent process of mixing the aggregate into the resin material and molding it.

In addition, most of the moisture contained in the aggregate is evaporated by the heating and drying process applied during aggregate molding, resulting in the generation of water vapor, which is considered to be a problem in resin molding using molded aggregate. There is no room for foaming, vinegar, rough skin, etc. to occur in the molded product. Furthermore, the removal of this water content also had a significant effect on the volatilization of wood acid contained in wood flour, and the wood acid contained in wood flour usually reacts with H2O groups. This is effectively inhibited by dissociation and volatilization. Therefore, as well as heating and crushing by impregnating the thermosetting resin material, removing the wood acid produced during the curing process, and adjusting the pH to 6 to 7 through neutralization, the generation of residual wood acid gas from the aggregate can be suppressed. This makes it even more effective.

The effective elimination and prevention of wood acid gas generation in such aggregates had an extremely important meaning in subsequent resin molding. In other words, when wood acid gas is generated during resin molding, the cylinder screw of the press, extruder, or injection machine used for resin molding, or the inner wall surface of the molding gou or mold is oxidized and corroded, reducing its durability. This extremely reduces the molding efficiency and also causes the problem of molding defects due to uneven extrusion and injection pressures.

In addition, in the case of ridge aggregate, unlike the usual pure wood flour,
By impregnating or adhering a curable resin into the aggregate, the surface resistance value is extremely reduced, and when molded as an aggregate into a resin material, the extrusion and injection pressure is lower than that of most common resins. It is close to that of .

Furthermore, the use of visible aggregate improves compatibility with the mixed resin material, ensures uniform mixing of aggregate, and eliminates as much as possible the voids that occur around the aggregate surface in molded products. This makes it possible to provide a molded plate (2) with the desired quality.

In the next step, the calcium carbonate powder prepared is necessary from time to time to prevent molded products from deforming during extrusion processing, etc., and to keep the unit price of molded products low since calcium carbonate itself is particularly cheap. It was used accordingly.

In addition to these materials, a stabilizer such as lead was separately prepared to prevent deterioration of the molded product and to minimize the frictional resistance generated during extrusion processing.

Furthermore, if the molded product is to be colored, a corresponding coloring agent is prepared. For example, if the molded product is to be colored white, titanium oxide is mixed in.

The materials described in detail above are provided in the form of pellets by being pre-mixed with a resin material such as vinyl chloride resin, and those that are mixed into powdered resin such as vinyl chloride resin. In some cases, it is supplied as a resin molding machine, and it is selectively supplied and used depending on the type of resin molding machine, etc. used.

Therefore, first, when making pellets, the above-mentioned aggregate is mixed with powdered resin in an amount of up to 50 wt%, calcium carbonate is added as needed within a range of up to 10 wt%, and then The necessary stabilizers, lubricants, and colorants are mixed in and heated under cross-wire heating to obtain pellets for molding.

Using the pellets for molding thus obtained, the desired composite shaped plate (2
) is obtained.

The other method that will be planned next is to directly obtain the molded plate (2) using a method similar to that used for making pellet sheets, and after putting various materials into a molding machine, cross-circuiting, and heating, molding is performed. something that has been accomplished.

20 to 60wt of aggregate that has undergone unique pretreatment in this way.
The synthetic resin plate (2) mixed within the range of
While laminating the veneer (1) and inducing secondary foaming, or without foaming, this is cooled with a press at around 30°C and molded into the desired shape to form a molded product.
In particular, it provides molding for doors and panel materials.

The decorative plywood according to the present invention has a characteristic structure on the ridges,
In particular, the plate (2) is a resin-molded plate made of a composite material provided using a unique molding method, and in creating the decorative surface, the elongation of the plate (2) and the elongation rate of the veneer (1) are adjusted. The difference was buffered by interposing a stretchable fabric such as cheesecloth (3), and the tensioning of the veneer (1) and the uneven patterning on the board (2) were achieved by press molding. By doing so at the same time, we were able to expect concrete results from the above-mentioned items.

In other words, by making the board (2) mixed with a large amount of wood flour-based aggregate, the degree of expansion and contraction caused by changes in temperature and the degree of expansion and contraction caused by changes in humidity are minimized. 1
), and the difference between the two is buffered by a stretchable fabric such as cheesecloth (3) interposed between the plates (1) and (2), and the adhesive surface is It is designed to reliably prevent the problem of peeling, and also to effectively prevent the occurrence of wrinkles, twists, warping, or tearing on the surface of the veneer (1). be.

In addition, when the veneer (1) is pressed in, the veneer (1) does not elongate compared to the elongation of the plate (2). The fear that the part may be cut due to pressing is avoided by using cheesecloth (3) interposed between the plates (1) and (2).

That is, the plate (2) softened by preheating is deformed into an appropriate shape by the press treatment, and the plate (1) laminated and bonded thereto is also deformed accordingly. ,
Since the plate (1) did not expand with heating and was almost in its original shape, the plate (1) on the adhesive surface was torn and damaged. However, by interposing the cheesecloth (3) on the adhesive surface that is shaken, the cheesecloth (3) stretches together with the board (2), and the cheesecloth (3) also stretches between the board (1) and the cheesecloth (3). ), the elongation of the plate (2) does not force the elongation of the plate (1), thereby effectively preventing the plate (1) from tearing or breaking.

In addition, the board (2) does not warp or distort due to changes in the amount of moisture absorbed, and the risk of peeling or distortion due to moisture, which is the case with ordinary plywood, is effectively prevented. This also effectively prevents the problem of distortion after molding, such as C on the resin plate.

Furthermore, by press-forming the board (2), it was possible to mold the plywood with the uneven decorative pattern having the decorative veneer (1) on the surface without requiring any other processing steps, making it extremely luxurious. This makes it possible to provide molded plates with carved wood patterns etc. at low cost.

In addition, by making the characteristics of board (2) as close as possible to those of wood, it can be used as a furniture or building material, with construction characteristics almost similar to veneer plywood, and can be sawed, nailed, etc. The color tone and feel of the material are similar to those of natural wood.

[Brief explanation of drawings]

Figures 1 to 3 are side views of the main parts showing the method for forming plywood according to the present invention, Figure 4 is a sectional view of the molded product, Figure 5 is an enlarged sectional view of the main parts, and Figure 6 is a perspective view of the same. It is a diagram. In addition, in the figure (1)... veneer, (2)... synthetic resin board,
(3)... Cheesecloth, (4)... Heating device, (5)...
...This shows the press device. Figure l Figure 3 Figure 2 Figure No. 111111 - Figure 4 Figure 5!

Claims (2)

[Claims] (1) For a resin molded product made by mixing 20 to 80% cellulose fine powder into a synthetic resin material and heat molding,
The veneer is attached through a stretchable sheet material while being reheated in the range of 0 to 140°C, and the veneer is compressed and molded from the surface of the attached veneer to the surface of the resin molded object. A method for forming decorative plywood characterized by laminating and integrating the layers. (2) The method for molding decorative plywood according to claim 1, characterized in that the cellulose-based fine powder has a tr+ diameter smaller than 100 mesh, and contains moisture within 5z.