JP2002192508A - Woody molded body, and method and equipment for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody molded body of which the degree of recovery from a compressed state induced by moisture, heat or others is small and which can be manufactured with high productivity inexpensively, and a method and equipment for manufacturing the same. SOLUTION: The woody molded body is manufactured by the method wherein a powdery, small-piece-shaped or fibrous woody material treated with a steam of high temperature and high pressure is compression-molded in a prescribed shape by using a press 12 and then the shape of the compression-molded woody material is fixed by using the press 12 and a high-frequency oscillator 13. On the occasion of fixation, the woody material is subjected to high-frequency induction heating by using the high-frequency oscillator 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden molded product produced from a powdery, small or fibrous wooden material, a method for producing the same, and a production apparatus.

[0002]

2. Description of the Related Art As a conventional wooden molded body of this type, there are, for example, a wooden board described in JP-A-10-166323, JP-A-6-91611 and JP-A-7-4751.
No. 1 discloses a consolidated wood material. JP Hei 10
Japanese Patent Publication No. 166323 discloses a wood board manufactured by subjecting a wood raw material such as wood flour to a softening treatment, thereafter compressing the wood raw material at a predetermined compression rate and performing a fixing treatment with high-pressure steam. ing. In addition, Japanese Unexamined Patent Publication No.
Japanese Patent No. 91611 is characterized in that wood is processed by high-frequency heating a compression-molded wooden material in a sealed pressure vessel while restraining deformation to convert the water inside the wooden material into high-pressure steam. A method for producing consolidated wood is disclosed. Further, Japanese Patent Application Laid-Open No. 7-47511 discloses that after a wooden material to be treated is accommodated in a rigid container having pressure resistance and heat resistance and which can be opened and closed freely, the rigid container is sealed and heated. Also disclosed is a method for heat-treating a wooden material, which comprises consolidating the wooden material contained in a rigid container.

On the other hand, Japanese Patent Application Laid-Open No. Hei 10-235613 discloses a method for producing deformed wood by heating and deforming the wood. A method for producing deformed wood characterized by heating the wood to a predetermined temperature in a short time is disclosed.

[0004]

However, in such a wooden molded body, since a stress originally intended to recover from a compressed state remains, the recovery occurs due to moisture, heat and the like. There is a risk. JP-A-10-166323
In the case of the woody board described in Japanese Patent Application Publication No. H10-265, although its recovery is suppressed to some extent as a result of the immobilization treatment using high-pressure steam, it is not necessarily sufficient, and further improvement in quality is required. Further, in the case of the wood board described in the publication, the steps of softening, compressing, and fixing are performed in one high-pressure vessel, so that the apparatus becomes large-scale and has low productivity.

[0005] Further, in the case of the compacted wood material described in JP-A-6-91611 and JP-A-7-47511, there is a disadvantage that the cost is increased because a high-pressure sealed container is required for the production thereof. .

On the other hand, the method for producing deformed wood described in Japanese Patent Application Laid-Open No. Hei 10-235613 is directed to one-piece wood.
It is not possible to apply the process to wood compacts made from powdery, flake or fibrous wood materials.

The present invention has been made by focusing on the problems existing in the prior art as described above. It is an object of the present invention to provide a woody molded product which has a small degree of recovery from a compressed state induced by moisture, heat, and the like, can be manufactured with high productivity, and is inexpensive, and a method and apparatus for manufacturing the same. Is to do.

[0008]

In order to achieve the above-mentioned object, the invention according to claim 1 is a method for preparing a powdery, small or fibrous woody material treated with high-temperature and high-pressure steam. Compression molding into a shape, and a step of fixing the shape of the compression molded wood material, a high-frequency dielectric heating of the wood material at the time of fixing Is the gist.

The present invention according to a second aspect of the present invention is a method for compressing a powdery, small or fibrous woody material treated with high-temperature and high-pressure steam into a predetermined shape, and then compressing the woody material. A wooden molded body obtained by fixing the shape of
The main point is that high-frequency dielectric heating of the wooden material is performed during immobilization.

According to a third aspect of the present invention, there is provided a compression molding means for compression-molding a powdery, small or fibrous woody material treated with high-temperature and high-pressure steam into a predetermined shape, and the compression-molding means. And an immobilizing means for immobilizing the shape of the wooden material, wherein the immobilizing means includes high-frequency dielectric heating means for high-frequency dielectric heating of the wooden material. I do.

According to a fourth aspect of the present invention, in the method for manufacturing a woody molded product according to the first aspect, the method is characterized in that the immobilization is performed in an open system.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram schematically showing an outline of a manufacturing apparatus for manufacturing a board-shaped wood molded product (hereinafter, also referred to as a wood-formed board) from a powdery, small-piece or fibrous wood material. The wood material used here has been previously treated with high-temperature (180 to 230 ° C.) and high-pressure steam. The woody material is obtained by crushing thinned wood, pruned foliage, driftwood and the like.

This manufacturing apparatus is provided with a compression / fixation section 11 for compressing and fixing a wooden material into a board shape. The compression / fixation unit 11 mainly includes a press machine 12 and a high-frequency oscillator 13. The press machine 12 is provided with a pair of molds 14 as shown in FIG.
The mold frame 14 includes an upper mold 141 having a convex portion 141a and a lower mold 142 having a concave portion 142a, and is formed when the upper mold 141 and the lower mold 142 are mated as shown in FIG. The cavity 143 has a board shape. The upper mold 141 and the lower mold 142 are connected to a heat source (not shown) so that the inside of the cavity 143 can be heated to a predetermined temperature. Furthermore, the upper mold 14
The first and lower molds 142 are provided with electrode boards 144 and 145 connected to the high-frequency oscillator 13. These electrode boards 144 and 145 are opposed to each other with the cavity 143 interposed therebetween.
A high frequency AC voltage of 300 MHz is applied.

[0014] The wood material is formed into a predetermined shape (board shape).
The compression molding means for compression molding mainly comprises a press machine 12, and the fixing means for fixing the shape of the compression molded wood material mainly comprises the press machine 12 and a high frequency oscillator 13. The high-frequency dielectric heating means for performing high-frequency dielectric heating of the wood material at the time of fixing is mainly composed of a high-frequency oscillator 1.
3 is comprised.

An input section 16 is connected to the compression / fixation section 11 via a first conveying means. The first conveying means mainly includes belt conveyors 15a to 15c,
The wood material supplied from the input unit 16 is compressed and fixed by the unit 1.
Convey to 1. The input section 16 is provided at an intermediate portion between the belt conveyors 15a to 15c arranged in a U-shape in a plane, and the wood material input to the input section 16 falls on the belt conveyor 15a. I have. The wood material dropped onto the belt conveyor 15a is the left and right (up and down in FIG. 1A) belt conveyors 15a.
b, 15c and the belt conveyors 15b, 1c.
5c.

Further, the manufacturing apparatus includes a compression / fixation unit 1
It has a cutting part 17 for cutting the wood molded board manufactured in 1 into a predetermined size, and an accumulating part 18 for accumulating the wood molded boards cut into the predetermined size. The cutting section 17 is connected to the compression / fixing section 11 via a second conveying means, and the stacking section 18 is connected to the cutting section 17 via a third conveying means. The second conveying means mainly includes a suction take-out section 19 and a belt conveyor 20, and conveys the wood forming board produced by the compression / fixation section 11 from the compression / fixation section 11 to the cutting section 17. Further, the third conveying means mainly includes a belt conveyor 20.
The wooden forming board cut into a predetermined size by the cutting unit 17 is transported from the cutting unit 17 to the collecting unit 18.

Next, a method of manufacturing a wooden board will be described. The production of a wood-formed board is performed through the steps of compression molding and immobilization in order. The compression molding process is performed at high
This is a step of compression-molding a powdery, small-piece or fibrous wood material treated with high-pressure steam into a predetermined shape. The wood material is fed into the feeding section 16 and is fed to the belt conveyors 15a to 15a.
The sheet is conveyed to the compression / fixation section 11 at 5c. Press machine 1
The second mold 14 can move to the end of the belt conveyors 15b, 15c.
The wood material conveyed to the end of c is directly supplied to the concave portion 142a of the lower mold 142 of the formwork 14. Recess 142a
When the amount of the woody material exceeds a predetermined amount, the mold 14 is moved into the press machine 12 and clamped, and the woody material is compression-molded. The compression molding is preferably performed at a pressure of 0.5 to 5 MPa.

The subsequent fixing step is a step of fixing the shape of the wood material compression-molded in the compression molding step.
By performing high-frequency dielectric heating and external heating on the wooden material in the closed mold 14, the shape of the wooden material is fixed, and a wooden molded board is obtained. The high-frequency dielectric heating is performed by arranging a compressed wood material in a high-frequency AC electric field formed between the electrode plates 144 and 145 when a high-frequency AC voltage is applied to the two electrode plates 144 and 145. Will be On the other hand, the external heating is performed by the upper mold 141 and the lower mold 1.
The heating is performed by a heat source (not shown) connected to 42. In addition, at the time of high frequency dielectric heating, the high frequency output per unit weight of the woody material is preferably in the range of 0.5 to 8 kW / kg.

The wood-formed board manufactured as described above is transferred from the compression / fixation unit 11 to the belt conveyor 20 by the suction take-out unit 19, and is conveyed to the cutting unit 17 by the belt conveyor 20. And the cutting part 17
After being cut to a predetermined size in, the sheet is further conveyed to an accumulation unit 18 by a belt conveyor 20 and accumulated.

According to the embodiment described above, the following effects can be obtained. -By performing high-frequency dielectric heating of the wood material at the time of immobilization, it is possible to obtain a wood-formed board having a small degree of recovery from a compressed state induced by moisture, heat, or the like. The reason is not clear yet, but in the case of high-frequency dielectric heating, unlike external heating, the object to be heated can be heated uniformly regardless of the surface or inside, which is one of the reasons. It is presumed.

The woody molded board of the present embodiment is manufactured through compression and immobilization using a woody material pretreated with high-temperature and high-pressure steam. For this reason, softening, compression,
The simplification of the apparatus and the improvement of the productivity can be achieved as compared with the conventional method (JP-A-10-166323) in which the fixing step is performed in one high-pressure vessel.

[0022] Among the conventional wooden molded bodies, there is known one formed by fixing a wooden material with an adhesive to form a predetermined shape. In the case of a wooden molded body containing such an adhesive,
In addition to VOC (volatile organic compound) problems such as formaldehyde in products, harmful gases are generated when incinerated, and adhesives remain without being decomposed when discarded. There were problems such as giving. However, since the wood molded board of the present embodiment does not use an adhesive, there is no possibility that the above-mentioned problem caused by the adhesive will occur.

The combined use of external heating and high-frequency dielectric heating at the time of immobilization provides advantages that cannot be obtained with external heating alone. For example, high-frequency dielectric heating has a higher heating efficiency than external heating, so that the energy cost in the immobilization process can be reduced. Further, since the temperature can be raised quickly, the time required for the immobilization process can be reduced.

In the case of the present embodiment, it is not necessary to use a closed system at the time of immobilization, such as performing immobilization in a closed container.
The fixation can be sufficiently performed in an open system. For this reason, compared with the case where the immobilization is performed in a closed system, the configuration of the apparatus for manufacturing the wooden molded body can be simplified,
Manufacturing costs can be reduced. It is considered that the reason why the immobilization can be sufficiently achieved in the open system without using the closed system is that the raw material is wood material treated with high-temperature and high-pressure steam. It is known that when wood materials are treated with high-temperature, high-pressure steam, some of the components contained in the wood materials are converted into adhesive components, and the adhesive components work well to fix even open systems. It is presumed that this can be achieved.

[0025]

Next, the embodiment will be described more specifically with reference to examples and comparative examples. (Example 1) Small pieces of woody material were treated with saturated steam at a high temperature and high pressure of 200 ° C for 15 minutes, and then dried until the water content became about 5%.
a (300 mm long × 300 mm wide × 80 mm deep). Then, the mold 14 is clamped, and 2.7 MPa
(28 kgf / cm ² ), compressed to a predetermined shape, and then subjected to high-frequency dielectric heating (13.56 MHz, output 200)
V, 5 kW) and external heating for 4 minutes.
The temperature was raised to 0 ° C. After the temperature reached 200 ° C., the shape of the wood material was fixed by maintaining the temperature at 200 ° C. for 20 minutes only by external heating. As a result, a wood-formed board having a length of 300 mm, a width of 300 mm and a thickness of 20 mm and a density of 0.7 g / cm ³ was obtained.

Example 2 The temperature was raised to 200 ° C. by high-frequency dielectric heating and external heating not by 4 minutes but by 5 minutes.
A wood-formed board was produced in the same manner as in Example 1 except that the change was performed over a period of minutes.

(Comparative Example 1) A small piece of woody material was softened as it was with saturated steam at 120 ° C, and the density after compression was 0.1%.
After compression to 7 g / cm ³ and treatment with high-pressure steam at 180 ° C. for 15 minutes, the mixture was cooled to produce a wood-formed board.

The results of measuring the recovery rate of the wooden molded board obtained in each of the above examples are shown in Table 1 below.
The measurement of the recovery rate was performed at two places, that is, the central part and the peripheral part of the wooden molded board. Here, the recovery rate is a value obtained according to the following equation. Recovery rate (%) = {(dimension after immersion treatment−dimension before immersion treatment) / dimension before immersion treatment} × 100 In the above formula, “immersion treatment” means that a wooden molded board is immersed in water for 24 hours.
The term “dimension” refers to the dimension in the compression direction of the evaluation sample (the dimension in the thickness direction in this example).

[0029]

[Table 1] As shown in Table 1, the wood-formed boards of Example 1 and Example 2 were both measured at the central portion and the peripheral portion.
The value of the recovery rate was smaller than that of the wooden molded board of Comparative Example 1. This indicates that the high-frequency dielectric heating of the wood material during the immobilization reduces the degree of recovery from the water-induced compressed state.

The above-described embodiment can be modified as follows. -In the said embodiment, although the shape of the wooden molded object was board-shaped, it is not limited to a board shape and may be a desired shape.

The wooden molded board of the above embodiment has a smooth surface, but may have a decoration such as embossing on the surface. In that case, for example, as shown in FIG. 3, desired work may be provided on the inner surface of the upper die 141 and the lower die 142 of the mold frame 14 to obtain a wooden molded board having decoration on the surface.

Next, the technical ideas that can be grasped from the above embodiment will be described below. The method for producing a woody molded product according to claim 1, wherein only the woody material is used as a raw material. According to this structure, it is possible to obtain a wooden molded body that does not cause a problem caused by the adhesive as in a conventional wooden molded body including an adhesive.

[0033]

Since the present invention is configured as described above, it has the following effects. Claim 1 and Claim 3
According to the invention described in (1), a wooden molded body having a small degree of recovery from a compressed state induced by moisture, heat, or the like can be manufactured with high productivity at low cost.

According to the second aspect of the present invention, the degree of recovery from a compressed state induced by moisture, heat, or the like can be suppressed to a low level, and high-productivity and low-cost production can be achieved. According to the fourth aspect of the present invention, in addition to the effects of the first aspect, the configuration of the apparatus for manufacturing a wooden molded article can be simplified.

[Brief description of the drawings]

FIG. 1A is a plan view schematically showing an outline of an apparatus for manufacturing a wooden molded product, and FIG. 1B is a side view thereof.

2 (a) and 2 (b) are cross-sectional views showing the operation of a mold of an apparatus for manufacturing a wooden molded product.

3 (a) and 3 (b) are cross-sectional views showing the operation of a mold of an apparatus for manufacturing a wooden molded product according to another embodiment.

[Explanation of symbols]

12: a press forming the compression molding means and the fixing means; 13 ... a high frequency oscillator forming the fixing means and the high frequency dielectric heating means.

Continued on the front page (72) Inventor Katsuhide Hayashi Gifu Pref. 72) Inventor Taiji Yamamoto 6-3-12 Kamishio, Tennoji-ku, Osaka-shi F-term in Yamamoto Vinita Co., Ltd. EB50 EC02 EC03

Claims (4)

[Claims] (1) a powdery substance treated with high-temperature and high-pressure steam;
A method for producing a wooden molded article, comprising: a step of compression-molding a small or fibrous wooden material into a predetermined shape; and a step of fixing the shape of the compression-molded wooden material. A method for producing a wooden molded body, wherein high-frequency dielectric heating is performed on the wooden material at the time of the heating. 2. A powdery state treated with high-temperature and high-pressure steam,
A wood compact obtained by compression-molding a small or fibrous wood material into a predetermined shape, and fixing the shape of the compression-molded wood material. A wooden molded body characterized by dielectric heating. 3. A powdery state treated with high-temperature and high-pressure steam,
An apparatus for manufacturing a wooden molded body, comprising: compression molding means for compressing a small or fibrous wooden material into a predetermined shape; and fixing means for fixing the shape of the compressed wooden material. An apparatus for manufacturing a wooden molded product, wherein the fixing means includes a high-frequency dielectric heating means for performing high-frequency dielectric heating of a wooden material. 4. The method according to claim 1, wherein the immobilization is performed in an open system.