JPH025164B2 - - Google Patents

Description

[Detailed Description of the Invention] (a) Technical Field The present invention belongs to the field of technology for artificially manufacturing decorative veneers by assembling veneers.

(b) Background technology The technology of producing laminated decorative veneers by laminating raw material veneers is already known. This technology was devised to produce high-grade precious wood veneers rather than low-grade logs, and has now reached the stage of practical application.

The outline of the manufacturing method for laminated veneer is as follows.

That is, the raw material veneer is manufactured from raw wood using rotary lace or the like. This veneer is bleached and pre-dyed as necessary, and then subjected to humidity control, and then an adhesive is applied and multiple veneers are laminated and pressed between molds with uneven surfaces. By integrating them to form a fritchi, and then slicing this fritchi, the desired laminated decorative veneer can be obtained.

However, the method for manufacturing decorative laminated veneers as described above is not necessarily a perfected technology, and various troubles have occurred during the manufacturing process. A typical problem was the occurrence of poor adhesion during the fritchi manufacturing process. This point will be specifically explained below.

FIG. 1 is a process diagram for illustrating a conventional pressing process. In this figure, 1 is a mold plate having an uneven surface, and 2 is a veneer pile made by laminating an appropriate number of raw material veneers. That is, first, in a first press, an appropriate number of raw material veneers (usually 50 to 150) are laminated with an adhesive interposed, and pressed together under relatively high pressure. In this case, there is a limit to the number of raw material veneers that can be pressed in one batch, and on the other hand, the required thickness of the frits is greater than that limit, so in order to satisfy both requests, a plurality of frits 2b A process was adopted in which the parts were joined together using a second press, as shown in Figure B. In the second press, a space veneer 2a was used for joining. Furthermore, in this second press, the pressure was tightened at a lower pressure than in the first press. In addition,
The mold plate 1a of the second press generally has the same mold surface as that of the first press.

The mold plate 1 used in the production of laminated decorative veneer is
It is a mold plate with an uneven surface, and is a vertically long mold plate with a cross-sectional shape similar to a gutter. When pressing a raw material veneer using the mold plate 1 having such an uneven surface, unevenness occurs in the pressure applied depending on the part of the mold. That is, the pressure is high at the ends (side edges) A of the mold, and the pressure is low at the center B. In order to achieve complete adhesion, it is necessary to apply pressure exceeding the limit even to this low-pressure part B, but in order to do so, it is necessary to increase the load pressure applied to the entire area, and in doing so, the pressure originally The high end A has a higher pressure. It is known that when bonding wood veneers, if the bonding pressure is too high, the bond strength will actually decrease. The graph in Figure 2 explains the situation during this time. The cause of this is that the adhesive present at the interface between the laminated veneers moves to the inside of the veneer or to the outside (edge) of the veneer due to high pressure, resulting in a lack of adhesive at the interface of the veneers to be bonded. This is said to be due to the occurrence of adhesion defects. For these reasons, poor adhesion of the fritches occurred. Poor adhesion of the frits significantly reduces the yield of sliced veneers.

(c) Purpose of the Invention This invention was made in view of the above circumstances, and was made with the purpose of reducing adhesion failures of frits in the production of laminated decorative veneers.

(d) Disclosure of the Invention The present invention is characterized in that a raw material veneer is used after being buckled by applying pressure treatment to the high-pressure load portion in advance. This will be explained in detail below with reference to FIG. 3 shown as an example.

Figure 3A shows the buckling press process.
3 is a mold plate used for buckling, and in this embodiment, it has the same mold surface as the mold plate 1 having an uneven surface, but this is not intended to be limiting. In other words, since the high pressure load part of the raw material veneer can be known in advance,
Buckling may be caused in that region by, for example, roll pressure, or a special buckling plate may be used. Further, the buckling treatment of raw material veneers may be performed on one veneer or on multiple veneers at once. Of course, in this case, there is no need to use an adhesive. Rather, no adhesive is involved. In short, it is sufficient to cause buckling in the necessary portions. However, it is convenient to use a buckling mold plate having the same mold surface as the mold plate 1 having an uneven surface because it is not necessary to know the high pressure load portion in advance.

3 corresponds to the conventional first pressing step. Here, in the usual manner, buckled raw material veneers are laminated with an adhesive interposed therebetween, and are clamped between mold plates 1 having an uneven surface. In this case, the clamping pressure applied is low pressure. In this case, since the first pressing is performed at a low pressure, the spring back phenomenon of the veneer does not occur, which also has the effect of reducing the deformation of the flitch after it is formed into a flitch. In this diagram 4
is a processed veneer pile that has been subjected to buckling treatment. Next, the second press is used to join and press the frit obtained by the first press at low pressure. Thereafter, the fritsch thus obtained is sliced to make a laminated decorative veneer. This slice is the same as before.

It should be noted that any technical matters that are not explained above and are necessary for implementing the present invention may be implemented according to the conventional example.

(e) Examples It was conducted under the following conditions.

Raw material veneer used: Tepa (yield stress is 16.7Kg/cm ² ) Shape of mold plate with uneven surface: Sine wave type (width 200
mm, amplitude 50mm) Adhesive: Urethane resin adhesive Buckling press pressure: 20Kg/cm ² 1st press pressure: 10Kg/cm ² 2nd press pressure: 10Kg/cm ² We sliced the fritschi to produce laminated decorative veneers and investigated their effects.

The rate of defective adhesion was 0.12 points/piece in the conventional case, whereas it was 0.07 points/piece in this example.

(f) Effects As explained above, the present invention is characterized in that the material veneer is subjected to a buckling treatment in advance at the high pressure load portion in the pressing process before being subjected to the fritting process, so that there is no possibility of adhesion failure. The effect was that it decreased.

[Brief explanation of drawings]

FIG. 1 is a process diagram of a conventional example, FIG. 2 is a graph showing the relationship between applied pressure and adhesive strength, and FIG. 3 is a process diagram for explaining an embodiment of the present invention. 1 is a mold plate with an uneven surface, 2 is a veneer pile, 3
1 is a buckling plate, and 4 is a processed veneer pile.

Claims (1)

[Claims] 1. A method for manufacturing a laminated decorative veneer, characterized in that the raw material veneer is subjected to a buckling treatment in advance at the high-pressure load portion in the pressing process before being subjected to the fritting process.