JPH04176602A - Manufacture of thin overlay veneer sheet - Google Patents

Abstract

PURPOSE:To surely, stably and continuously produce overlay veneer sheet, which satisfies all the required quality characteristics, by a method wherein resin-impregnated sheet is fixed onto the resin surface provided on a fixed plate and, after that, overlay veneer is pasted onto said sheet and then hot-pressed and resultant laminates are subjected to stacked curing for a certain period of time. CONSTITUTION:Resin-impregnated fibrous sheet 3 is produced by immersing fibrous sheet 2 in a polyurethane-based resin 13-containing impregnating tank 14 and drying so as to be placed onto a smooth fixed plate 2, the surface of which is covered with resin, in order to be fixed by heating. Under the condition that a thermosetting water-soluble adhesive 4 is applied on the resin-impregnated fibrous sheet 3 fixed on the fixed plate and, in succession, thin overlay veneer 5 is stacked on the adhesive 4 applied on the fixed plate 2, the fixed plate 2 is hat-pressed with a hot press 19 so as to bring its bond strength expressed in terms of limit peeling strength by peel angle of 90 deg. within the range of 30-200g/25mm width. Next, under the condition that a plurality of hot-pressed fixed plates 2 are stacked, a pile 10 of the plates 2 is subjected to stacked curing at normal temperature so as to bring the water content of each thin overlay veneer sheet to 6-15%. After the regimen is completed, the surface of the thin overlay veneer sheet 1 on the fixed plate 2 is polished mechanically. After that, the surface of the polished thin overlay veneer sheet 1 is coated with paint. Finally, the coated thin overlay veneer sheet 1 is peeled off the fixed plate.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a method for manufacturing a decorative thin veneer sheet.

The present invention is generally utilized for manufacturing decorative veneer sheets having the following uses. Architectural interior materials such as wall materials, ceiling surface materials, column covering materials, movable partitions, surface materials for interior products of automobiles and ships, exterior decorative materials for furniture such as chests of drawers, exterior decorative materials for general wooden products such as fixtures, etc. ; and exterior decorative materials for electronic devices and musical instruments.

In particular, the present invention provides a decorative thin veneer useful as a raw material for decorative wood products having interlocking patterns made of dissimilar materials, especially for the production of decorative veneer sheets that require high dimensional stability and no deformation. Applicable to sheet manufacturing.

(Prior art) Due to the depletion of natural wood resources, especially precious wood resources, today, instead of solid wood boards, decorative veneer sheets made of thin mock boards backed with fiber or resin sheets are widely used. There is.

Such decorative veneer sheets are generally required to have the following quality characteristics.

■No deformation of the sheet, such as warping, rippling, cracking, etc. 6 Above all, it is required that no rippling deformation occurs.

■Residual stress inside the sheet should be as low as possible.

■The entire sheet should have little directionality and high homogeneity.

■The sheet has high dimensional stability and is not affected by changes in ambient temperature and humidity conditions.

■The surface of the sheet must be highly smooth.

■The sheet must be flexible and have appropriate strength.

■Secondary adhesion on the back of the sheet must be good.

In particular, the above-mentioned conditions (1) to (2) are required when using this sheet to process a decorative wood product (for example, an inlaid natural wood decorative board) having an interlocking pattern between a plurality of different wood species materials.

(Problems to be Solved by the Invention) However, none of the decorative veneer sheets thus far have satisfied all of the above-mentioned quality characteristics.

In particular, the characteristics of decorative veneer sheets required when processing decorative wood products with interlocking patterns made of different materials (
Regarding items (■ to ■) above, there was a great need for improvement.

These characteristics will be discussed further below.

-About characteristic (■)- The reason why it is required to prevent the occurrence of cracking and deformation is that deformed decorative veneer sheets are difficult to process, such as cutting.

Decorative veneers are naturally susceptible to the surrounding temperature and humidity conditions, and depending on the nature of the veneer itself, it may be more or less prone to deformation or deformation6. It varies depending on cutting conditions (especially drying conditions). In particular, the veneers of half-bow and kofu-hanbow, which are said to be the highest quality wood veneers (wood species include elm, zelkova, maple, and tsuallnut, etc.), are particularly rough.

On the other hand, in the case of thick decorative wood boards made by pasting such decorative veneers to general plywood, the veneer is forcibly held in a flat shape due to the strong rigidity of the plywood, making it possible to suppress the occurrence of cracks. be.

However, in decorative veneer sheets, the rigidity of the backing material on the underside of the veneer is generally weak, so there has always been a problem of rough deformation.

However, in the past, relatively thick decorative veneers with a thickness of 0.5 to 0.6 seconds have been mainly used, but recently, with the depletion of precious wood resources, thicker decorative veneers have been used. Decorative veneers with a thickness of 0.15 to 0.30 mm have come to be used from the viewpoint of economy.

As a result, the need to prevent accidents was greater than ever, and further improvements were required.

-About characteristics■- It is necessary to reduce the internal residual stress of the decorative veneer sheet as much as possible because if the residual stress is large, the decorative veneer sheet will deform immediately after cutting due to the stress, and the decorative veneer sheet will be deformed immediately after cutting. This is because you will not be able to judge.

Regarding one characteristic (2) - Wood is a non-uniform material which is inherently directional and has different cutting conditions with a knife in the fiber direction, radial direction and tangential direction. Wood has a hard springwood part and a soft summerwood part depending on its growth, and there is also heterogeneity depending on the arrangement of vessels and board vessels, the orientation of wood fibers, etc. Therefore, if such non-uniformity remains strongly in the decorative veneer sheet, the cutting path of the blade or the hard radial tissue may be avoided during cutting, resulting in the sheet being cut off from the predetermined cutting line. This is because it will be done.

Regarding one characteristic (2) - When forming a fitting pattern of different materials, an operation is performed in which a part of the - material is cut out and a completely identical part made of another material is fitted into that part.

However, if the dimensional stability of the sheet is poor, the above-mentioned cut-out portions may overlap each other or gaps may be formed between the cut-out portions.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to reliably produce a decorative veneer sheet that satisfies all of the required quality characteristics described above, such as not causing deformation or deformation. It is an object of the present invention to provide a method for manufacturing a decorative thin veneer sheet that can be stably and continuously produced.

In particular, it is an object of the present invention to provide a method for manufacturing a decorative veneer sheet that is optimal as a material for processing decorative wood products with interlocking patterns made of different materials.

(Means for Solving the Problems) The inventor of the present invention conducted extensive research to solve the problems, and found that first, a resin-impregnated sheet was fixed on the resin surface of a fixing plate,
This is obtained by applying a manufacturing procedure in which a decorative veneer is pasted on top of the veneer, which is then heat-pressed and cured for a certain period of time, after which the surface of the veneer is painted, and finally it is separated from the fixed plate. Decorative thin veneer sheets do not undergo deformation such as cracking, have high dimensional stability, are unaffected by changes in dimensions or surrounding temperature and humidity conditions, and can be reliably cut as specified. In particular, they discovered that this material is optimal for processing decorative wood products with interlocking patterns made of different materials, and completed the present invention.

Therefore, the method for producing a decorative thin veneer sheet according to the present invention includes the following steps: (a) impregnating a fibrous sheet with a resin solution and drying to produce a resin-impregnated fibrous sheet; (b) impregnating the resin-impregnated fibrous sheet with a resin solution; a step of placing the sheet on a smooth fixing plate whose surface is coated with resin and fixing it by heating; (c) a step of applying an adhesive onto the resin-impregnated fibrous sheet of the fixing plate; Subsequently, a decorative thin veneer is further placed on the adhesive of the fixing plate, and the fixing plate is heat-pressed in a hot press machine; (e) Next, the plurality of heat-pressed fixing plates (f) After the curing is completed, mechanically polishing the surface of the decorative thin veneer sheet on the fixed plate; (g) After that, the surface of the polished decorative thin veneer sheet is (h) Finally, the painted decorative thin veneer sheet is peeled off from the fixed plate, and is then heat-pressed.

Conventionally, the typical manufacturing method for decorative veneer sheets was to sequentially laminate each element of the decorative veneer sheet, and then glue or press them to finish the sheet (Japanese Patent Laid-Open No. 60-104329). No., Japanese Patent Publication No. 60-165241
No., JP-A-2-15384).

Also, is there a case where a release base material is used?
No. 39G1, JP-A No. 64-0258, JP-A No. 61-5
No. 3204), these were merely base materials for curing the adhesive, molten resin, etc. above the mold release base material to form a layer.

In contrast, the greatest heat compaction in the method of the present invention is that the fixing plate is passed through steps (b) to (h) for the production of the veneer sheet. The purpose of the present invention is to manufacture decorative thin veneer sheets on the fixed plate after fixing each material, especially the sheet base material (resin-impregnated fibrous sheet) on the fixed plate.

As a result, similar to the case of decorative plywood with a veneer attached,
During the manufacturing process, the decorative veneer is held in its flat form on a fixed plate, which prevents the occurrence of cracks and the like, and reduces and relieves internal stress. Moreover, joint work for decorative veneers becomes easier.

In addition, in the final step (h), the fixed plate is separated from the decorative thin veneer sheet, and by returning it to step (b), it can be reused for subsequent production of the veneer sheet. . That is, the solid plate is manufactured by steps (b) and (c).
, (d), (e), (f), (g)
, (h) and again in a loop process consisting of the wave order of (b).

The fixing plate may be one provided with a smooth resin surface layer, but it is particularly preferable to use one coated with polyester resin or a wood base material such as general plywood or MDF. The method of resin coating is arbitrary, and a resin solution is applied onto the base material, or a resin film is applied onto the base material with an adhesive.
Preferably, the adhesive is attached with a nonwoven fabric interposed therebetween. A polyethylene film may be used instead of a polyester film. A method of coating the upper surface of the fixing plate with a mold release agent such as silicone resin or stearin salt may also be adopted.

Another feature of the present invention is the use of a resin-impregnated fibrous sheet as the backing material.

The resin-impregnated fibrous sheet imparts appropriate strength and flexibility to the entire veneer sheet, and in step (c)
It acts as a filler to prevent the adhesive applied by the adhesive from penetrating into the surface of the fixing plate.

Further, it is advantageous in that it can be brought into close contact with the resin surface of the fixing plate.

The resin-impregnated Ht fibrous sheet is produced in step (a) by impregnating a fibrous sheet, such as Japanese paper, paperboard, woven fabric, or nonwoven fabric, with a resin, preferably a polyurethane resin or styrene-butadiene rubber latex, and drying it. do.

The fibrous sheet is preferably a nonwoven fabric, more preferably a nonwoven fabric made from rayon or nylon.

In addition, the amount of resin to be impregnated is set at 5% solid so that a predetermined adhesion strength can be obtained between the fixed plate and the resin-impregnated fibrous sheet.
Does it need to be gem2 or higher? The appropriate amount of resin impregnation varies depending on the material and basis weight of the fibrous sheet, but
~: In the case of a fibrous sheet (polyester/bulb nonwoven fabric) of 10 g/m2, an appropriate impregnated amount of solids is 7 to 15 g/m2.

The resin-impregnated fibrous sheet is generally fixed to the fixing plate in step (b) using a hot roll or a hot press.

Another feature of the present invention is that by such fixing, gluing and heat pressing, the decorative veneer is placed on the fixing plate during each manufacturing process.
The goal is to make it adhere to the surface to the extent that it does not peel off and can be easily tightened in the end.

This made it possible to mechanically polish the surface of the veneer using a sander or the like in step (f), thereby facilitating the formation of a uniform coating film in the next painting step (g). Decorative veneer itself cannot be polished uniformly by mechanical polishing.

The degree of adhesion depends on the type of resin-impregnated fibrous sheet used, the material of the surface of the fixing plate, the amount of resin impregnated, the hot pressing conditions, etc., and the conditions of these elements should be adjusted to obtain the optimal one. should be selected.

For example, in step (d), the fixing plate is heat-pressed so that the adhesion strength between the decorative thin veneer sheet and the fixing plate is in the range of 30 to 200 g/25 mm width using the limit strength in a 90° bee linter as an indication. Is it preferable to do so?

Furthermore, another characteristic feature of the present invention is that after such heat pressing, a predetermined number of fixed plates (decorative veneer, adhesive and resin-impregnated fibrous sheet The process consists of stacking and curing the laminates.

During curing, the decorative veneer comes into contact with the lower surface of the fixing plate, so moisture in the decorative veneer and adhesive gradually transfers to the wood base material of the fixing plate, and the decorative veneer etc. dry. During the drying period, the laminate of the decorative veneer, adhesive, and resin-impregnated fibrous sheet remains completely fixed to the upper surface of the fixing plate. Therefore, due to the try ink set effect, etc., the dimensions of the laminate on the fixing plate are stabilized while maintaining the form of a flat sheet, which is similar to when the rotating laminate is heat-pressed without being fixed to the fixing plate. In comparison, dimensional stability is significantly improved.

In pile curing, it is preferable to pile up a plurality of fixing plates (usually around 10 plates) while they are still hot after heat pressing, and leave them at room temperature until the moisture content of the decorative thin veneer sheet is below the equilibrium moisture content. Continue to do this until it reaches a normal 6-15%.

Furthermore, another feature of the present invention is that the surface of the decorative thin veneer sheet on the fixed plate, which has been deposited and cured, is preferably painted with a polyurethane resin paint after mechanical polishing.

This makes it possible to more stably maintain the planar form of the decorative thin veneer sheet on the fixed plate that is held in a planar form, and to make it less susceptible to the influence of surrounding temperature and humidity conditions. It is possible to reduce the amount and improve homogeneity.

From the above, a preferred manufacturing method according to the present invention is one in which the following items are added.

■In step (a), a fibrous sheet is impregnated with polyurethane resin or styrene-butadiene rubber latex to produce a resin-impregnated fibrous sheet, and in the steps after step (b), a polyester resin or wood base material is used. Use a fixed plate coated on the surface.

■In step (d), the fixing plate is fixed so that the adhesion strength between the decorative thin veneer sheet and the fixing plate is in the range of 30 to 20 [1 g/25 dust layer radiation], based on the limit strength at 90° peeling. Heat press.

(2) In step (e), a plurality of fixing plates are piled up while hot after being hot-pressed, and left to pile up and cure at room temperature until the moisture content of the decorative thin veneer sheet reaches about 6 to 15%.

(2) In step (g), polyurethane paint is used to coat the surface of the decorative thin veneer sheet.

■In step (c), for adhesion of decorative thin veneer,
Use thermosetting water-soluble adhesive.

Note that the decorative veneer that can be used in the present invention is made of various precious woods, for example, with a thickness of 0.10 to 3.0 mm, preferably thin < (0.15 to 0.4 mm thickness), Examples include carved sawn boards and model boards. The grain of the decorative veneer does not matter, and it can be straight-grained, continuous-grained, board-grained, or heathered. Furthermore, the wood species of the veneer is not particularly limited. Examples of suitable tree species include cypress, oak, zelkova, cherry tree, elm, dotbo, horse chestnut, katsura,
Enju, maple, camphor; rosewood, teak, mahogany, ebony, rosewood, bird's eye maple, American flak walnut, black walnut, latenu walnut, finsland walnut, zebra wood, mangashiro, tsurashirian rose, calici, hersimon. , Silver Rose, Parma, Retwood, Purplewood.

There are Silky Oak, Formosan, Cherry, Macnolya, Black Leo (Tao), White Leo, Saberi, Hubinka, Makore, Matroner, Myrtle, Maple, Arasin, and Imbuyer.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows a decorative thin veneer sheet 1 made by the method of the example. The sheet 1 includes a resin-impregnated fibrous sheet 3, a thermosetting water-soluble adhesive (for example, styrene phtadiene rubber latex) 4, a decorative veneer 5 with a thickness of 0.15 to 0.40 mm, and a polyurethane-based adhesive. It is formed by sequentially laminating coating films 6 of resin paint.

FIG. 3 shows the fixing plate 2 used in the method of the example. The fixed plate 2 is formed by pasting a polyester film on a wood base material (for example, plywood, MDF) 7 with an adhesive and covering it with a polyester resin 8.

Next, a method for manufacturing the decorative thin veneer sheet 1 shown in FIG. 2 according to an example will be described. The process will be explained in order according to the diagram s1.

Step 1 (a) - Step (1) of pulling out a fibrous sheet (polyester/pulp nonwoven fabric) 12 from a raw roll and immersing it in an impregnating tank 14 containing a polyurethane resin 13.
Subsequently, it is passed through a drying oven 15 to undergo a drying step (2).
) ), a resin-impregnated fibrous sheet 3 was produced.

Step 1 (b) - The resin-impregnated fibrous sheet 3 made in step (a) is supplied onto the fixing plate 2, and heated and pressed by a heat roll 16,
The sheet 3 was fixed on the fixing plate 2, and then cut into the size of the plate 2 by a cutter 17 (steps (a) and (b)
).

Step 1 (c) - Next, a predetermined amount of thermosetting water-soluble adhesive 4 was applied to the resin-impregnated fibrous sheet 3 on the fixing plate 2 using a coating device 18 such as an applicator roll (step (c) ).

Step 1 (d) - Subsequently, the decorative thin veneer 5 was further placed on the adhesive 4 of the fixing plate 2 (step (d)).

Then, the fixed plate 2 with the veneer 5 placed thereon is placed on the hot press machine 1.
For example, 105°C x 90 seconds x 6 kg/c
It was hot pressed under conditions of m2 (step (e)).

In this process, the adhesion strength between the decorative thin veneer sheet 1 and the fixing plate 2 was set to be in the range of 30 to 200 g/25 mm width, with the limit strength at 90° peeling as an indication.

Step 1 (e) - Next, a laminate 9 of the heat-pressed fixing plate 2 and a veneer, etc.
- are taken out from the hot press machine and stacked again while still hot, and the stacked body 10 is left at room temperature for about 24 hours until the moisture content of the decorative thin veneer sheet reaches about 8 to 12%. It was deposited and cured (step (f)).

The laminate of the decorative veneer 5, the adhesive 4, and the resin-impregnated fibrous sheet 3, which were integrated by heat pressing, was kept in a stable planar form on the fixing plate 2 after curing was completed (step ( g
)).

Step 1 (f) - Thereafter, the surface of the veneer of the laminate on the fixed plate 2 was mechanically polished using a sander 20 (step (h)).

-Step (g)- Next, using the coating device 21, the surface of the polished decorative veneer is coated with polyurethane paint to form the coating film 6 as the top layer.Step (i)): Decorative thin veneer Sheet 1 was finished on fixing plate 2 (step (j)).

Step (h) - After that, the finished decorative thin veneer sheet 1 is peeled off from the fixing plate 2 (step (k)'), and the obtained sheet 1 is
The patterning described next was sent to the production process. On the other hand, it was decided that the remaining fixing plate 2 would be stored and reused in step (1)) and then in step (b). Therefore, the fixing plate 2 could be reused in thousands or several directions without any problem.

The produced decorative thin veneer sheet does not fray or warp even if there are large changes in ambient temperature and humidity, always maintains its planar shape, and the amount of dimensional change is also greater than that of conventional sheets of this type. It was extremely small.

Furthermore, in the following usage example, when cutting out this sheet, the amount and frequency of deviation from the trajectory of the knife from the predetermined cutting line was significantly smaller than in the past, and was to the extent that it did not cause any practical problems.

Example of Use 1 Using the prepared decorative thin veneer sheet 1, a decorative wood board 23 with an interlocking pattern made of different materials as shown in FIG. 5 was manufactured.

To explain the patterning process, as shown in Figure 4,
Using an NC knife and an NC laser, portions A of the same shape are cut out from decorative thin veneer sheets 1a and 1b of different wood species, and the cutout portion of sheet la is inserted into the cutout hole of sheet lb. By inserting the cutout part of the sheet lb into the cutout hole of the sheet la, replacing each other with each other, pasting this onto a suitable base material, and pressing it, it is possible to fit a veneer of a different wood to the surface. A decorative wood board 23 forming a mating pattern was manufactured (FIGS. 5(a) and 5(b)).

In addition, a portion A of the same shape is cut out from the metal (A1) sheet 24, and this is inserted into the cut-out hole of the sheet 1a to produce a decorative wood board 23 whose surface forms a pattern of fitting a veneer and a metal plate. (Fig. 5(c)
)).

Both decorative wood boards 23 have extremely good dimensional stability, and defects such as overlap between the cutout portion A and its surroundings or gaps between these portions do not occur even if the surrounding temperature and humidity conditions change significantly. Ta.

(Effects of the Invention) As described above, according to the manufacturing method of the present invention, it is possible to reliably produce a decorative thin veneer sheet that satisfies all of the various quality characteristics required for a decorative veneer sheet, particularly the following characteristics. It is possible to produce it continuously.

(a) Not affected by changes in conditions such as ambient temperature and humidity;
No deformation such as cracking or warping occurs.

(b) The residual stress inside the sheet is very small, making it possible to cut the sheet to predetermined dimensions.

(c) There is almost no directionality in the sheet, and when it is cut, it rarely deviates from the trajectory of the blade or the predetermined cutting line.

(d) The influence of surrounding temperature and humidity conditions, etc. is extremely small.
It has very high dimensional stability.

Therefore, the present invention makes it possible to provide a decorative veneer sheet that is particularly suitable as a surface material for processing decorative wood products with interlocking patterns made of different materials.

[Brief explanation of drawings]

FIG. 1 is an overall view showing the manufacturing process of a decorative thin veneer sheet by the method of the embodiment of the present invention, FIG. 2 is a sectional view showing the decorative thin veneer sheet manufactured by the method of the embodiment, and FIG. 1 is a cross-sectional view showing the fixing plate shown in FIG. 1 used in the method of the embodiment, and FIGS. 4 and 5 are views showing the process of manufacturing a decorative wood product having a fitting pattern using different materials. In the figure, 1... Decorative thin veneer sheet 2... Fixed plate 3... Resin-impregnated fibrous sheet 4... Adhesive 5... Decorative veneer 6... Paint film 7... Wood base material 8...Resin film A...Cut-out portion of the interlocking pattern Agent Patent attorney Yumi Sakai and 2 others Figure 2 (Q) Figure 4 Figure 5 (b) (c) 1b' IQ

Claims (6)

[Claims] (1) (a) A process of impregnating a fibrous sheet with a resin solution and drying it to produce a resin-impregnated fibrous sheet; (b) fixing the resin-impregnated fibrous sheet on a smooth plate whose surface is coated with resin; (c) applying an adhesive onto the resin-impregnated fibrous sheet of the fixing plate; (d) then applying the decorative thin veneer to the adhesive of the fixing plate; (e) Next, stacking the plurality of heat-pressed fixing plates and curing them in piles; (f) Curing. (g) Then, the process of painting the polished surface of the decorative thin veneer sheet with paint; (h) Finally, painting. A method for producing a decorative thin veneer sheet comprising the step of peeling off the decorative thin veneer sheet from a fixed plate. (2) In step (a), a fibrous sheet is impregnated with polyurethane resin or styrene-butadiene rubber latex to produce a resin-impregnated fibrous sheet, and step (
2. The manufacturing method according to claim 1, wherein in the subsequent step b), a fixing plate having a surface of a wood base material coated with a polyester resin is used. (3) In step (d), the fixing plate is hot pressed so that the adhesion strength between the decorative thin veneer sheet and the fixing plate is in the range of 30 to 200 g/25 mm width using the limit strength at 90° peeling as an indication. 3. The manufacturing method according to claim 1 or 2. (4) In step (e), multiple fixing plates are piled up while hot after being heat-pressed, and piled and cured at room temperature until the moisture content of the decorative thin veneer sheet becomes about 6 to 15%. The manufacturing method according to any one of claims 1 to 3. (5) The manufacturing method according to any one of claims 1 to 4, wherein in step (g), a polyurethane paint is used for surface coating of the decorative thin veneer sheet. (6) In the step (c), a thermosetting water-soluble adhesive is used for adhering the decorative thin veneer.
The manufacturing method according to any one of the above.