JPS6235882B2 - - Google Patents

Description

[Detailed Description of the Invention] (1) Purpose of the Invention The production of decorative veneers using laminated wood is popular. In other words, rotary veneer is obtained from natural wood logs,
This is suitably dyed and laminated and pressed using an adhesive to form a frit, from which a sliced veneer is obtained. And a veneer (wood grain) that approximates natural wood veneer.
It is becoming possible to obtain However, attempts are being made to develop methods for producing laminated veneers with even higher fidelity. The present invention was made with the aim of realizing a sharp grain profile, especially in summer wood such as cedar.

In general, rotary veneers develop "back cracks" due to their manufacturing method. Back cracks are countless fine cracks that occur on the back side (cutting tool side) of a rotary veneer, and when they occur, the adhesive being applied can penetrate, causing various defects.
Specifically, even if you try to express the sharp summer wood grain characteristic of cedar wood, that is, the dark and thin summer wood grain, the dark-colored summer wood forming adhesive will penetrate through the cracks in the back. , it is no longer possible to express the sharp summer wood part.

The present invention provides a method for representing wood grain that does not have these drawbacks.

(2) Structure of the Invention The present invention involves applying an adhesive colored in the color of spring wood to the cracked back surface of a rotary veneer, overlaying a transfer sheet darkly colored in the color of summer wood, and applying the adhesive colored in the color of summer wood. The veneer is characterized by transferring the colored summerwood color, then laminating and pressing the boards using a light summerwood colored adhesive so that the grains are exposed, and slicing to obtain veneers.

The present invention will be explained below based on the drawings.

The figure is a process diagram of a method for manufacturing a veneer according to the present invention. First, a rotary veneer 1 is prepared. This includes back cracks (cracks) that occur when making veneers.
2 is occurring. An adhesive colored in spring wood color is applied to this back crack surface 3 to form an adhesive layer 4. The reason for forming the adhesive layer 4 in advance here is to prevent the summer material forming adhesive to be applied later from entering through the cracks in the back. When the adhesive layer 4 colored in the spring wood part color is formed in advance, even if this spring wood color adhesive penetrates into the veneer, the color of the veneer constituting the spring wood part will not change, and The adhesive layer 4 prevents the dark colored summer material forming adhesive from entering. The adhesive is preferably a one-component moisture-curing urethane adhesive. Next, cover with the transfer sheet 6. The sheet is preferably made of plastic, and the printed layer, which will be explained later, can be easily peeled off. For example, sheets of polyethylene, polypropylene, polyester, etc. are preferred. Of course, any surface treatment may be used. A darkly colored adhesive layer 5 is formed on the side of the transfer sheet 6 that is in contact with the veneer, and this layer 5 is transferred by a press transfer operation or the like. In this case, the color of the summer wood should be a color that is convenient for expressing the grain of the wood. Titanium yellow, titanium white, tapiyu yellow, etc. are used for toning. The reason why the transfer printing method is adopted here is as follows.

In other words, in order to express the sharp wood grain of the summerwood part like cedar, it is necessary to form a dark and fine grain, but in order to do this, a dark and thin summerwood layer is formed using an adhesive. There is a need to.

To form a dark adhesive layer, it is necessary to apply a highly concentrated adhesive to the veneer, but the higher the concentration, the higher the viscosity, so there is no way to form a thin adhesive layer. It becomes difficult both physically and equipment-wise.
It is virtually impossible. On the other hand, it is also possible to apply by increasing the amount of pigment in the vehicle and reducing the concentration of the paint, but in this case, the paint becomes more likely to be impregnated into the veneer, or uneven application occurs.
In the end, it becomes impossible to express the summer wood, which is dark in color and thin in thickness.

In the transfer printing method, an adhesive layer is formed on the plastic sheet in advance, and since it is formed on the plastic sheet, there are no disadvantages as described above when forming it on a veneer surface, and it is easy to print thick and thin layers. An adhesive layer can be formed as a summer material layer. This is the reason for adopting the transfer printing method.

Once the transfer is complete, peel off the sheet 6, stack and press the resulting colored veneers (in a way that is convenient for expressing the grain) to create a fritchie 7, and slice this fritchi to reveal the grain. That's what I do. In this case, the summer materials are laminated and pressed using a light-colored adhesive. The reason for using an adhesive colored in the light color of the summer wood is that although the grain of the summer wood is intended to be sharpened, if the color suddenly changes at the boundary between the grain of the summer wood and the grain of the spring wood, the natural feel will be lost. This is because the material is lost, and in order to create a more natural look, the material is fritted using an adhesive colored in the light color of summer wood. Note that this adhesive is preferably used by applying it to the side of the rotary veneer on which the colored adhesive layer is not provided. The veneer 8 obtained by slicing has a grain pattern, and the outline of the summerwood part is sharp and has a natural feel. Even if an attempt is made to express the grain of the board using only a simple dyeing operation, the coloring agent will seep out from the tip 9 of the summer wood part of the grain, and the outline will become blurred. According to the present invention, such a problem does not occur. Note that the portion 10 is the dark color portion of the summer material transferred by the transfer sheet 6.

(3) Effect The present invention applies an adhesive colored in the spring wood color to the back cracked surface of the rotary veneer to form a spring wood color layer.
On top of that, a transfer sheet with a dark summer material layer made of printing ink is layered and transferred with the summer material layer on the veneer side, then the transfer sheet is peeled off, and adhesive colored in a light summer material color is applied. Since it is characterized by laminating and pressing through a compound, forming flitches, and slicing, it is possible to express the grain of the summer wood section sharply.

(4) Example Rotary sliced veneer of South Sea wood (thickness 1mm)
After cutting it to a predetermined size, it was degreased and bleached using the usual method, and then dyed in the color of spring wood. This dyed veneer is dried to a predetermined moisture content (40 to 100%) to produce a veneer to express the grain of artificial cedar.

First, apply 60 to 80 g/ ^m2 of a colored adhesive (one-component moisture-curing urethane adhesive) formulated to match the color of spring wood to the back side of the veneer, and then apply the dark color of summer wood on top of that. A transfer sheet with a layer of printing ink toned to the desired color was placed on top (the dark summer material colored layer was placed on the veneer side). Then, the layer is transferred using a press, and the sheet is peeled off.
On the thus obtained colored veneer, apply 80 to 100 g/m ² of a colored adhesive (one-component moisture-curing urethane adhesive) formulated in the light color of Natsuzai (on the opposite side to the transfer surface). Next, a predetermined number of these sheets were stacked in the same direction, pressed together to obtain frits, and sliced so that the grains were exposed.

In the sliced veneer obtained as above,
The wood grain has a sharp outline at the tip of the grain, and the wood grain is very similar to that of natural cedar.

[Brief explanation of the drawing]

The figure is a process diagram according to an embodiment of the present invention. 1...Rotary veneer, 2...Spring material color adhesive layer, 5...Transfer film.

Claims (1)

[Claims] 1 Apply an adhesive colored in the spring wood color to the back cracked surface of the rotary veneer to form a spring wood colored layer, and then apply a transfer sheet on which a dark colored summer wood layer is formed using printing ink as described above. It is characterized by stacking and transferring the summer wood layer with the veneer side, then peeling off the transfer sheet, and laminating and pressing through an adhesive colored in a light summer wood color, forming a frit, and slicing. Manufacturing method for laminated veneer.