JP2717465B2 - Manufacturing method of decorative veneer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[Industrial application] A method for manufacturing a decorative veneer.

[0002]

2. Description of the Related Art Conventionally, decorative veneers have been manufactured by the following method. That is, first, the wood flitch is steamed or boiled to adjust the water content above the fiber saturation point, and the wood flitch is cut in a wet state. After obtaining the veneer, the veneer is dried as required.

[0003] However, the above-mentioned conventional method for producing a veneer has the following problems.

(4) At the time of harvesting wood, the flitch itself bends and cracks occur due to internal residual stress. . . . . . . {Circle over (b)} The number of defective parts increases in cutting, resulting in poor productivity and high cost. . . . . . . ▲ c ▼
In addition, the wood itself is contaminated by water-soluble wood components due to steaming or boiling.

[0005]

[Technical Means for Solving the Problems] The present invention has been conceived of the following technical means for solving the problems of the prior art. That is, the technical means of the present invention is "a method for producing a decorative veneer by cutting a wood flitch after forming a wood flitch on wood in which the internal residual stress of the wood has been reduced by a heat treatment by a dry method". This is the configuration.

[0006] The present invention has an advantage that cutting can be performed without resistance irrespective of soft material or hard material due to the idea of the above technical means.

[0007]

[Description of Configuration] The configuration of the above technical means will be described in detail below.

First, raw wood is subjected to a heat treatment by a dry method. The heat treatment by the dry method means that the raw material is heated in a heating furnace using a heater that uses electricity, gas, or oil as a heat source, wood, rubber, or the like, or combustion gas of waste materials, and electromagnetic or far-infrared energy. Is directly heated. Wood mainly contains cellulose, hemicellulose and lignin. The thermal decomposition temperature of these components is cellulose 260-310 ° C, hemicellulose 230-260.
℃, lignin 310 ~ 450 ℃, the heating temperature is preferably 230 ℃ or less. (The furnace atmosphere temperature is 23
(The temperature may be 0 ° C. or more, and the surface of the material is kept at 230 ° C. or less). Cellulose, hemicellulose, and lignin, which are the main components of wood, exhibit a heat softening temperature of 60 to 90 ° C. (up to 100 ° C.) under wet conditions.
It is mainly associated with the thermochemical reaction of hemicellulose and α-cellulose. Change to a polymer with low hygroscopicity (polymerization, etc.)
Moisture absorption and water resistance are reduced due to the bonding of cellulose chains by hydrogen bonding (sticking of cellulose), reduction of equilibrium water content due to reduction of carbohydrates such as hemicellulose and α-cellulose, and weight reduction due to reduction of water content. It is improved and dimensional stability is achieved. In addition, the hydrophobicity decreases the polarity and decreases the bonding strength between molecules. For this reason, on the structure of the cell wall, the cell wall supporting mechanism in cooperation with cellulose and lignin of hemicellulose becomes slow,
The cell wall itself softens. Accordingly, bending, Young's modulus, bending strength, bending, toughness and the like are reduced. Therefore, resistance at the time of cutting and cutting is reduced, and cutting and cutting can be easily performed. Further, the internal residual stress of the wood is reduced, and the stress deformation accompanying the internal residual stress is suppressed during the subsequent processing. For this reason, the heating temperature and the heat treatment time are controlled such that the temperature inside the wood due to the heating becomes 100 ° C. or less, preferably 60 to 90 ° C., which is the heat softening temperature, near the center thereof. In addition, those controls are arbitrarily selected depending on the species and size of the raw wood. In this way, the raw wood is reduced in internal residual stress.

Next, the raw wood is cut to obtain a wood flitch having a reduced internal residual stress as shown in FIG. The raw wood has a reduced internal residual stress, softened and reduced in stress during cutting, and can be easily cut, and a wood flitch free of bending, twisting and cracking can be obtained. Alternatively, instead of the above-described process, after raw wood is cut into large wood flitches in advance, the wood flitch is subjected to a heat treatment to reduce internal residual stress, and further obtained by re-cutting the wood flitch to a predetermined size. Is also good.

Next, the wood flitch is cut by a cutting device 2 (slicer, half rotary race, rotary race, etc.) as shown in FIG. 2 to obtain a decorative veneer 3 shown in FIG. The wood flitch 1 is made of a wood flitch whose internal residual stress is reduced along with softening, so that cutting can be easily performed. Since the wood flitch is reduced in internal residual stress and stabilized in size, the obtained decorative veneer is free from twisting, warping, warping, and the like due to a difference in stress, a difference in contraction and expansion. This is the same effect when the decorative veneer is dried as required.

The decorative veneer is obtained from a heat-treated wood flitch, and has improved moisture absorption and water resistance, and is dimensionally stabilized.

The decorative veneer is subjected to a drying treatment as required.
When the internal temperature of the wood in the heat treatment becomes 100 ° C. or higher, the wood becomes a non-decomposed region from the heat-softened region of the main component, manifests the alteration of the component itself, and the strength such as bending Young's modulus, bending strength, bending toughness, etc. is significantly reduced This is not preferred.

[0013]

[Effect] The use of wood flitch, which has softened wood and reduced internal residual stress due to heat treatment by a dry method, reduces cutting resistance, making it easy to cut not only soft wood but also hard wood. No cracking during cutting, twisting, warping, warping, etc. of the veneer veneer after cutting occur, and the blade life is extended. In addition, a veneer veneer having improved moisture absorption resistance and water solubility and excellent dimensional stability can be obtained.

When a decorative veneer is used as a decorative veneer bonded to a substrate via an adhesive, the veneer veneer itself has excellent dimensional stability and small expansion and contraction. Does not occur.

[Brief description of the drawings]

FIG. 1 is a perspective view of a wood flitch in which internal residual stress of wood is reduced by a heat treatment by a dry method.

FIG. 2 is a perspective view during cutting.

FIG. 3 is a perspective view of a veneer veneer 1 wood flitch 2 cutting device 3 veneer veneer

Claims (1)

(57) [Claims] 1. A decorative veneer, comprising: forming a wood flitch from wood whose internal residual stress has been reduced by heat treatment by a dry method; and cutting the wood flitch into a decorative veneer. Production method.