JP2000043003A - Method for molding laminated veneer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for molding a laminated veneer which is resistant to cracking and breaking even in a part deformed largely when the laminated veneer in which wood of a cedar and others is laminated with an adhesive is pressed in a molding. SOLUTION: A laminated veneer 32 produced by bonding veneers with a thermoplastic adhesive, after the adhesive being cured, is exposed to steam for 20-40 see to soften the laminated veneer 32. The laminated veneer 32 exposed to steam is pressed by a molding press in which a projected mold 11A and a recessed mold 11B are set. In the pressing, a hot press heated at 80-180 deg.C by a heater or steam is used, and a pressing time is 20-40 sec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a single veneer obtained by cutting wood with a slicer or a rotary lace, or a laminated veneer obtained by laminating a plurality of thin wood plates (hereinafter collectively referred to as veneer) processed by lumber. It relates to a molding method.

[0002]

2. Description of the Related Art Hitherto, products have been manufactured in which a laminated veneer obtained by laminating a plurality of veneer veneers is formed into a desired shape by forming and pressing with a mold.

[0003]

However, wood is not a material having high ductility and malleability, unlike rubber and metal. Therefore, when a laminated veneer is formed and pressed using a mold that causes deformation of a certain limit or more, cracks and cracks occur in portions having a large amount of deformation, and the product does not become a commercial product. For example, when a dish-shaped product such as 21 shown in the perspective view of FIG. 2 is manufactured from a laminated veneer, a crack or a crack may be generated in the corner portion 22 having a large deformation amount, and the occurrence rate of defective products is high. .

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and provides a method for forming a laminated veneer which is less likely to crack or crack even when the laminated veneer is pressed by a mold and molded. It is characterized by the steps of bonding a plurality of veneers into a laminated veneer, curing the adhesive of the laminated veneer, and curing the adhesive of the laminated veneer. Thereafter, a step of irradiating the laminated veneer with steam and a step of forming and pressing the laminated veneer immediately after the vapor irradiation are provided.

[0005]

Embodiments of the present invention will be described below. Here, a case where three single plates are stacked will be described. When three veneers are laminated, veneer (upper layer) 31A, veneer (middle layer) 31B, veneer (lower layer) 31 as shown in FIG.
C is bonded so that the wood fiber directions are orthogonal to each other.
The applicant conducted an experiment by using a single plate 31 of cedar having a thickness of 0.2 to 0.8 mm and an adhesive of vinyl acetate. FIG.
Indicates a laminated veneer 32 to which the veneer 31 is bonded in this manner. FIG. 4 does not show the adhesive layer.
1A and the single plate 31B, and between the single plate 31B and the single plate 31C are bonded.

[0006] The laminated veneer 32 that has just been bonded has a low adhesive strength because the adhesive layer is not cured, and the adhesive veneer 31 and veneer 31
Contains a large amount of water, so hot pressing causes the water to evaporate, causing problems such as a so-called puncture phenomenon. Therefore, in the present invention, the molding press is performed after the veneers are bonded and the adhesive is cured. The time for the adhesive to cure is, for example, about 1 to 3 hours at room temperature, depending on the humidity, in the case of a vinyl acetate adhesive. Note that the adhesive can be cured in a short time by using high frequency.

When the adhesive of the laminated veneer 32 is cured as described above, the laminated veneer 32 is irradiated with steam 51, for example, as shown in FIG. The laminated veneer 32 is heated by the irradiation of the steam, and both the veneer layer and the adhesive layer are softened. About 2 steam
Irradiate for 0-40 seconds.

[0008] The laminated veneer 32 irradiated with steam is formed by a molding press 1 in which a convex mold 11A and a concave mold 11B are set as shown in FIG.
Press 2 As the press, a hot press in which the mold 11 is heated to about 80 to 180 degrees by a heater or steam is used. The pressing time is about 20 to 40 seconds. As described above, when the laminated veneer 32 is formed and pressed immediately after the steam irradiation, that is, while the laminated veneer 32 is in a soft state, the dish-shaped product 21 shown in FIG.
Cracks and cracks are less likely to occur even in a portion having a relatively large amount of deformation, such as the corner portion 22, and the product yield is improved.

As another method of irradiating the laminated veneer 32 with steam, as shown in FIG.
The steam injection port 61 may be provided in A, and the steam 51 may be irradiated to the place where the laminated veneer 32 is set. In this way, it is possible to immediately shift from the steam irradiation to the forming press.

In the above description, a vinyl acetate adhesive is used as the adhesive, but other adhesives may be used as long as they are thermoplastic adhesives.

[0011]

As described above, according to the present invention, after the adhesive of the laminated veneer is hardened, the laminated veneer is softened by irradiating steam after the adhesive is cured, and then molded by a molding press immediately after that. In addition, cracks and cracks are less likely to occur even in areas where the amount of deformation during molding is relatively large, improving the product yield and greatly expanding the range of products manufactured by molding laminated veneers. Having.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a perspective view of a product manufactured according to the present invention.

FIG. 3 is an explanatory view of a laminated veneer.

FIG. 4 is an explanatory view of a laminated veneer.

FIG. 5 is an explanatory view of vapor irradiation on a laminated veneer.

FIG. 6 is an explanatory diagram of steam irradiation on a laminated veneer.

[Explanation of symbols]

 12 forming press 31 veneer 32 laminated veneer 51 steam

Claims (3)

[Claims] 1. A step of bonding a plurality of veneers into a laminated veneer, a step of curing the adhesive of the laminated veneer, and after the curing of the adhesive of the laminated veneer, steam is applied to the laminated veneer. A method for forming a laminated veneer, comprising: irradiating the laminated veneer and pressing the laminated veneer immediately after the irradiation with steam. 2. The method for forming a laminated veneer according to claim 1, wherein said adhesive is a thermoplastic adhesive. 3. The method according to claim 1, wherein said forming press is a hot press at 80 to 180 degrees.