JPH10202611A - Method for modifying parawood material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve grain to be fine and obtain wooden materials having less warp or deformation due to drying by specifying both of temperatures of circulating hot air and heat treatment hours for parawood materials. SOLUTION: A plurality of parawood materials to be treated are arranged while maintaining a predetermined distance from one another in a circulating tank and are subjected to heat treatment for treating time of 2.5 hours by circulating hot air at a high temperature of 190-210 deg.C in the interior of the circulating tank. In this case, when a temperature is lower than 190 deg.C, the fine color of the materials is not produced to have a value-added, and no effect on the elimination of fuzz is produced. When the designated treatment temperature exceeds 210 deg.C, the materials are deteriorated, and the proper strength of the materials as furniture is not obtained. The high-temperature hot air circulating process at 190-210 deg.C can treat the parawood materials in a relatively uniform manner without detriment to them even in the case where they are relatively thick members. By treating them in such a way, the adhesive strength of the heat-treated materials shows an increase, and this method has even a good effect on improvement in their adhesive strength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for modifying a parawood material (rubber material).

[0002]

2. Description of the Related Art Conventionally, hardwoods used for furniture and the like are no longer hardwood depleted, and therefore, in most cases, they rely on imported timber. Countries have set forth forest conservation policies to protect the global environment, and the International Tropical Timber Organization (ITT)
Since 2000, only wood that can be sustainably managed will be traded.

[0003] Therefore, "wood that can be sustainably managed" refers to a tree that grows quickly after planting. Many countries around the world are trying to surpass the development of this tree. It is an earth-friendly tree.

[0004] This parawood material does not correspond to a precious wood [valuable wood], and furthermore, warpage or irregularity is caused by drying, time is required for base polishing, and fluff is likely to be formed when entering a painting process. There are drawbacks in processing, such as uneven coloring and difficulty in clogging the wood, and the wood is not suitable for furniture as compared with the wood used so far.

[0005] However, this parawood material has a stable supply, can be repeatedly planted, has an appropriate strength, has a white base color, and has a desired material color.
Since the wood has advantages such as being unrestricted, it is desired to improve the above-mentioned drawbacks and to convert the wood into a valuable material.

Conventionally, heat treatment is considered to be effective for the dimensional stability of wood, and methods of modifying wood by heat treatment have been attempted, such as a flame method, a heat and pressure method, and a hot and pressure roll method. Although there are a high pressure steam method and a thermal fluidized bed method, all have drawbacks and are not suitable as heat treatment methods.

[0007] For example, a method of heating and pressurizing [JP-A-6
JP-A-2-209286], or a method of improving the dimensional stability by performing a heating and pressurizing treatment after performing a steam heating and pressurizing treatment (JP-A-4-135702).
Furthermore, a method of performing a heat treatment with far infrared rays [JP-A-7-13]
No. 9880].

[0008] In such a means, the wood to be treated is broken or the inside of the material is colored (only the surface is colored).
It does not work, or is out of order, is not good, and after further processing, has a large amount of swelling.
However, the supply of this parawood material is stable, it can be repeated, it has moderate strength, the base color is white, and there are advantages in using it, such as being not restricted by the target material color. Therefore, somehow, a processing method was required.

[0009]

SUMMARY OF THE INVENTION Therefore, the present invention
It was invented in order to eliminate the above-mentioned drawbacks, and by specifically specifying the heat treatment means as `` processing by circulating high-temperature hot air '', it was possible to convert conventionally inappropriate wood into furniture. Parawood that can be used as a material, has less turbulence afterwards, has the same color to the inside, has no fluff, has better clogging of wood eyes, and can be dried to obtain a material with less warpage and crazy The purpose is to develop a method for modifying materials.

[0010]

SUMMARY OF THE INVENTION The present invention specifies parawood reforming means as means for circulating high-temperature hot air and heat-treats the parawood material for a necessary time to reform the material. .

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described in detail. In the circulation tank, the thickness is 27 mm to 45 mm and the width is 100 m.
A plurality of materials to be processed (parawood materials) having a length of 1000 mm and a length of 1000 mm are arranged at predetermined intervals, and one material is placed inside the circulation tank.
The heat treatment is performed by circulating a high-temperature hot air of 90 ° to 210 ° for 2.5 hours.

[0012]

According to the present invention, a test material heat-treated with high-temperature hot air at 200 ° C. for 2.5 hours is allowed to remain indoors for 75 days from July 9, 1996 to September 21, 1996. The test material was allowed to stand, and the thickness and width of the test material were measured every day. At the same time, the untreated material without heat treatment was measured at the same time. Then the ASE was calculated. The results were also effective in dimensional stability as follows. ASE = (D ₀ −D) ÷ D ₀ × 100 D ₀ = Untreated swelling rate D = Swelling rate of heat-treated material Width direction = 27.8 Thickness direction = 13.8

The heat treatment temperature and shear strength are as shown in the table below.

[0014]

[Table 1] Unit when the specific gravity is 0.65 g / cm ² ; kg / cm ² [all treatment time is 2.5 hours]

If the temperature is lower than 190 ° C., the material color is not excellent, no added value is obtained, and there is no effect of reducing fluff. If the temperature exceeds 210 ° C. within the specified processing temperature, the material to be processed deteriorates. It has been found that the strength of the wood is no longer appropriate for furniture, and that the parawood material can be processed relatively uniformly by the high temperature hot air circulation method at 190 ° to 210 ° without damaging relatively thick members.

Next, the adhesion test is as follows. [Unit: specific gravity]

The sample was an untreated wood which was imported parawood glued wood, the one with a specific gravity of 0.534 to 0.685 was a heat-treated wood, and a 25 mm plate was made of an aqueous vinyl similar to the untreated wood. It is bonded with urethane. And
This is the result of a normal block shear test.

The test piece had a cross-sectional area of 5 cm ² , and was heat-treated by circulating at 210 ° C. for 2.5 hours (may have some width before and after).

From these results, it can be seen that the adhesive strength of the heat-treated material is increased, and that this method is also effective for improving the adhesive strength, which is extremely useful.

Claims (1)

[Claims] 1. A reforming method, wherein a parawood material is heat-treated by circulating hot air at a high temperature of 190 ° to 210 ° for a processing time of about 2.5 hours.