JPH0747511A - Method for heat treating wooden material - Google Patents

Abstract

PURPOSE:To provide a simple and stable method for heat treating wooden materials to produce compacted wooden materials used effectively for furniture. CONSTITUTION:A wooden material 40 is compacted by compressing and heating with compression equipment having heating platens 50, 50 after placed in a pressure and thermal resistant rigid container 10, 20 that can be opened and closed freely through a sheet member provided when necessary. This method helps the wooden material to be compressed sufficiently to the center easily and in a very short time, protect packings used at the time of treatment from movement and damage, and allow long continuous treatment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat treatment method for wood materials, and more particularly to a consolidated wood material that can be effectively used for construction or furniture by improving the dimensional stability or surface characteristics of the wood materials. TECHNICAL FIELD The present invention relates to a heat treatment method for wood materials, which enables easy and stable production of wood materials.

[0002]

2. Description of the Related Art In recent years, high-quality hardwood materials have decreased and it is no longer possible to obtain a sufficient supply. Therefore, softwood materials, medium-quality fiberboard (MDF), particle board and the like are attracting attention as alternative materials for hardwood materials. However, softwoods are generally softer than hardwoods, and to be used as building or furniture materials, surface properties such as surface hardness and surface abrasion resistance, durability against moisture and heat, and strength, etc. There was a problem. Swelling of MDF and particle board in the thickness direction with respect to water has been a serious problem.

For this reason, softwood is boiled or steamed to be softened, and then hot pressed with a flat plate press to consolidate the softwood to a thickness of about 20 to 70% of the initial thickness. Is publicly known. When the softwood is consolidated, the above-mentioned surface properties, durability, and strength can be obtained significantly, but the consolidated softwood material tends to return to its original state by the action of one or both of water and heat. There was a drawback that the softwood material that had been strengthened and improved in performance was restored to near its original state due to the force.

A method for preventing restoration of the consolidated wood material by putting the consolidated wood material in an autoclave and treating it with high-pressure steam at 160 to 220 ° C. for several minutes has been proposed. It was difficult for the high-pressure steam to penetrate into the wood material (especially in the middle part of the wood material), the treatment effect was not uniform, and the treatment condition of the center portion and the peripheral portion of the wood material sometimes differed.

The Applicant has conducted extensive studies to solve the inconveniences of the conventional methods for treating wood materials, and not only prevents the consolidated wood materials from being restored to their original thickness by moisture or heat, but also A new treatment method for wood materials, which can uniformly and efficiently process wood materials over the entire wood material, has been devised and already filed (Japanese Patent Application No. 5-28957).
issue).

[0006] This processing method is a method of using a pressing device having a heating plate used in conventional wood processing without processing the wood material in the autoclave, and processing between the heating plates of the pressing device. After arranging the wood material to be made, and further arranging the elastic sealing material such as elastic silicon material and the thickness control jig such as stainless material around the wood material, the wood material is heated and compressed by the hot plate to This is a method of consolidating wood materials by vaporizing the water contained in the wood itself, and it can be performed using a press machine with a normal hot plate used for wood compression and composite material production. The process itself is simplified.

[0007]

Although the above-described heat treatment method for a wood material using a pressing device having a heating plate is effective in itself, the wood material to be processed is not heated by the pressing plate of the pressing device. Since it is necessary to place an elastic sealing material and a thickness control jig around it every time it is placed on top and remove them after the consolidation process, try to consolidate a large number of relatively small wood materials. It is undeniable that this will be a complicated task. Also, when the processing temperature is high, the internal vapor pressure generated becomes large, and the elastic sealing material and the thickness control jig may move or deform under the influence of the pressure, and the generated water vapor is kept airtight. It may happen that it is not done. In addition, since it is basically assumed that the surface of the hot platen used conventionally is used as a pressing and consolidation surface, the surface of the wood material to be treated depends on the surface condition of the hot platen. Therefore, it is difficult to obtain those having more or different surface characteristics.

An object of the present invention is to provide a method which is a further improvement of the above-mentioned heat treatment method for wood materials, which has been proposed by the applicant of the present invention. The work before and after is extremely simple,
It is possible to perform a stable consolidation treatment regardless of the treatment temperature, and it is possible to obtain a consolidated wood material having surface characteristics that do not depend on the surface condition of the hot plate of the compaction device,
It is to provide a heat treatment method for wood materials.

[0009]

In order to solve the above problems and to achieve the object, the present invention provides a wood material to be treated inside a rigid container having pressure resistance and heat resistance and which can be opened and closed. Disclosed is a method for heat treating a wood material, characterized in that the wood material housed in the rigid container is consolidated by heating the rigid container in a sealed state after heating.

There is no particular limitation on the method of heating the rigid container containing the wood material in a sealed state and heating it.
It can be performed by a pressing device having a heating platen, or by a roll press or a belt press having heating means. In any case, it is effective to use high-frequency heating as a heating method from the viewpoint of shortening the processing time and homogenizing the processing, and it may be used as a single heating means and with a heating means such as a heating plate. You may use together.

According to the present invention, further, a wood material to be treated is housed in the container body of a rigid container having a container body and a lid part and having pressure resistance and heat resistance, and the lid part is arranged thereon. After that, by heating the rigid container in a sealed state to heat-consolidate the wooden material contained in the rigid container, a method for heat treating a wooden material, the surface of the wooden material to be treated and the bottom surface of the container body. Between or between the front surface of the wood material to be treated and the back surface of the lid portion, or both, a sheet-like member such as a silicone rubber sheet is preferably arranged, and the lid portion is installed in that state. After that, a heat treatment method for a wood material, which comprises heating the rigid container in a sealed state, is also disclosed. According to this method, it is possible to easily manufacture a product having surface characteristics according to the physical properties of the sheet-shaped member used, and it is possible to further improve the sealing property.

Hereinafter, the wood heat treatment method according to the present invention will be described in more detail with reference to the accompanying drawings. First, in the present invention, the wood material includes not only solid wood but also processing materials such as MDF and particle board, and the same purpose can be achieved. Further, although the effect is particularly exerted by applying the present invention to a softwood material which is generally considered to be soft as a solid material, it can also be applied to a hardwood material.

The rigid container 1 used for compaction is preferably made of a compressed wood material such as a container body 10 having a space S for containing wood material therein and a flat lid portion 10 as shown in FIG. It is composed of two members that are separable in the direction.
Stainless steel is preferable as the material of the rigid container 1, but the material is not limited to this, and any material having resistance to temperature and pressure during consolidation can be arbitrarily used. For example, iron material,
Aluminum material or the like can also be used. Also, the container body 1
It is not always necessary to form the lid 0 and the lid portion 20 with the same material. The container body is made of stainless steel, and the lid body is made of a heat resistant resin material such as epoxy, silicon, or polycarbonate. May be. In that case, there is an advantage that the weight of the rigid container as a whole is reduced and the handling becomes easy.

A sealing material 30 such as a heat-resistant silicon material is preferably provided at a portion where the container body 10 is surface-bonded to the lid portion 20.
Install. As shown in FIG. 3, the stored wood material 40
A sealing material 30A such as an elastic silicon material may be separately provided around the sealing material, and in this case, the sealing material 30 is not always necessary. Further, the surface of the rigid container 1 in contact with the wooden material 40 to be treated may be wholly or partially mirror-finished, or may be finely textured. In the former case, a consolidated wood material with a flat surface can be obtained, and in the latter case, a consolidated wood material with a matte surface can be obtained.

Further, as shown in FIG. 3, between the back surface of the lid portion 20 and the wood material 40, the entire surface of the container body 10 on the open side is covered so that the thickness is 0.3 to 1.0 mm, preferably 0. .3 ~
A sheet-shaped member 20A such as a resin sheet such as a Teflon sheet having a thickness of about 0.5 mm, a silicon rubber sheet, or a release paper may be interposed depending on the purpose, whereby the surface characteristics of the rigid container (for example, the lid portion) and In addition to being able to obtain a consolidated wood material having different surface characteristics, can improve the workability because the distance between the rigid container and the wood material can be improved. The area of the sheet-shaped member 20A is preferably the same as the cross-sectional area of the rigid container 10 but somewhat larger.
Thereby, it becomes possible to enhance the sealing property of the joint surface between the container body 10 and the lid portion 10. Although not particularly shown, a sheet-like member may be similarly arranged between the bottom surface portion of the container body 10 and the wood material 40, if necessary.

In particular, when a silicone rubber sheet is used as the sheet-shaped member 20A in the form as shown in FIG. 3, the high adhesiveness of the silicone rubber sheet improves the sealing property in the container and the steam generated from the wood material becomes rigid. It is possible to more reliably prevent the product from flowing out of the container and obtain a product with a high degree of consolidation, and due to the high elastic modulus of the silicon rubber sheet, unevenness according to the hardness distribution on the surface of the wood material is formed on the surface. There is an effect that it is possible to obtain a consolidated product having a higher design property.

The cross-sectional shape of the space S formed inside the container body 10 is arbitrary as long as it can accommodate the wood material 40 to be treated, but as shown in FIG. It is a practically preferable mode to make the cross-sectional shape somewhat larger. Although only one length is shown in FIG. 2, the width W of the container body 10 is the width w of the wood material 40.
Are formed to be somewhat larger (that is, W> w).
On the other hand, the depth H is shallower (lower) than the thickness h of the wood material 40 to be treated before treatment (that is, H <h).

When heat-treating the wood material 40, first, the lid portion 20 is removed from the rigid container 1 and the wood material 40 to be processed is accommodated in the internal space of the container body 10 (at that time, as described above, the bottom portion of the container is closed). Alternatively, as shown in FIG. 3, a sheet-like member such as a silicone rubber sheet may be arranged between the lid portion 20 and the wood material). In that state, as shown in FIG. 2, a part of the wood material 40 in the thickness direction, that is, a portion (h-H) is in a state of protruding from the upper edge portion of the container body 10. The lid portion 20 is placed on the protruding surface of the wooden material 10 and is placed between the heating plates of the pressing device.

As described above, as the hot platen, a normal hot platen used for compressing wood or manufacturing a composite material can be optionally used, but the hot platen is not limited to this. Further, a conventionally known heating roll press or heating belt press may be used.
In that case, a heat treatment proceeds by arranging a rigid container containing the wood material on the upstream side of the press and moving it to the downstream side while performing compression and heating. further,
High-frequency heating including microwave heating (hereinafter referred to as high-frequency heating in the present specification) may be used alone or together with a heating plate as a heating means. A wave generator or a high frequency generator should be provided.

A rigid container 1 containing a wood material for processing.
2, the heating plates 50, 50 are brought close to each other until they come into contact with the rigid container 1 as shown in FIG.
Are brought close to each other until they come into contact with the container body 10. Thereby, the wood material 40 is compressed in the rigid container 1 and placed in a sealed state. In that state, heating by the heating plate is further continued. It is necessary that the heating temperature at this time is equal to or higher than the temperature at which the water contained in the wood material evaporates. The heating temperature may be changed stepwise, for example, by initially setting the temperature to about 200 ° C. and gradually lowering the temperature, or by heating at a lower temperature after the elapse of a predetermined time, the discoloration of the surface of the wood material due to heat is prevented. It is possible to prevent it as much as possible. When high-frequency heating is used instead of or in addition to heating by a heating plate, more uniform heat treatment is performed because moisture is uniformly vaporized from inside the wood material, and the processing cycle is further shortened. Planned.

In the present invention, the initial thickness of the wood material 40 accommodated in the rigid container may be approximately the same as the depth H of the internal space of the rigid container 1. In that case, the wood material is not particularly subjected to the compression treatment, but only the heat treatment by vaporizing the internal moisture is performed. When it is necessary to densify and improve the surface condition like softwood, it is preferable to prepare a material thicker than the thickness of the final product, but it is particularly necessary to consolidate such as particle board. In the case of the non-use material, the above-mentioned treatment is possible.

Further, in the case of a material produced by reworking an intermediate material such as MDF or particle board as the material, the treatment according to the present invention may be carried out in the step of forming into a wooden material, and produced as a wooden material. The processed product may be subjected to post-treatment (therefore, in the present invention, the term "wood material" is used to include an intermediate material in the molding process).

After the predetermined heating is completed, the pressure is released. The decompression may be performed gradually over a certain period of time, or may be performed in a so-called cold state by supplying cooling water to the hot platen. According to the experiment, when the decompression is performed in the cold state, the dimensional change rate of the obtained final product is smaller than that in the case of other decompression, and the surface condition can be finished beautifully.

As described above, in the present invention, the depth (height) H of the internal space of the rigid container is the thickness of the wood material to be treated after consolidation. Therefore, the depth H of the internal space is appropriately determined for each final product to be obtained, but as described above, a thin plate-shaped member having heat resistance and pressure resistance is laid on the bottom of the internal space separately from the sheet-shaped member. As a result, it is possible to obtain a product after consolidation having different thicknesses even if the container main body having the space of the same depth is used.

[0025]

EXAMPLES The present invention will be described below with reference to examples. [Example 1] As a wood material, water content 20%, thickness h = 3
A cedar material having a width of 0 mm, a width of w = 150 mm and a length of 1 = 600 mm was prepared, placed in a stainless steel rigid container having a shape shown in FIGS. 1 and 2, and compressed and heated. The dimensions of the internal space formed in the container body 10 of the stainless steel rigid container 1 are as follows: height H = 12 mm, width W = 160 mm, length L = 6.
A stainless plate having a thickness of 10 mm and a thickness of 10 mm was used as the lid portion 20. Further, a heat resistant elastic silicone packing 30 was attached to the upper edge of the container body 10 around its four circumferences.

The container body accommodating the cedar material and the lid portion placed on the upper part thereof are arranged on the lower heating plate of the pressing device having the heating plate, and the heating plate is set at 200 ° C., and then the pressure is 50 kgf / c.
The heating platen was moved at m ² , and the lid portion 20 was brought into contact with the upper edge of the container body 10. In that state, heating is continued for 5 minutes and 10 minutes, then cooling water is supplied to the hot platen, the pressure is decompressed for 5 minutes, the rigid container is taken out from between the hot plates, and a consolidated wood material is obtained. It was Initially, the thickness of the cedar wood was 30mm, but 12
It was compressed to mm (compression rate 60%).

Example 2 The material used in Example 1 was used, and here a press having a hot platen capable of applying high frequency was used. As the rigid container, a container made of a stainless steel container body and a polycarbonate lid portion was used. After setting the heating plate to 180 ° C, the pressure is 50 kgf / c
The heating platen was moved at m ² , and the lid portion 20 was brought into contact with the upper edge of the container body 10. In that state, 13.56MHz, output 20
After irradiating a high frequency of 0 V 8 kw for 2 minutes and 4 minutes, cooling water was supplied to the hot plate and decompressed for 5 minutes, and the rigid container was taken out from between the hot plates to obtain a consolidated wood material. Initial thickness 30
The cedar material that had been 10 mm was compressed to 12 mm (compression rate 60
%).

Example 3 The same process as in Example 2 was performed. However, before placing the lid part made of polycarbonate, a 0.2 mm PET sheet was laminated on the surface of the wood material, the lid part was placed on it, and compression and heating were performed. Example 4 The same process as in Example 2 was performed. However, a 0.4 mm-thick silicone rubber sheet was laid on the inner bottom of the rigid container body, and the wooden material was placed on it. further,
Before placing the polycarbonate lid part, stack the same silicone rubber sheet on the surface of the wood material so as to cover the entire open side of the container body, place the lid part on it and compress and heat. went.

[Comparative Example] Using the materials used in Examples 1 and 2, treatment was carried out in accordance with the heat treatment method for wood materials according to the applicant's earlier application (see Japanese Patent Application No. 5-28957). It was That is, the cedar material is placed on the lower heating plate of the pressing device, the elastic silicon material having a height of 32 mm and a width of 30 mm is used as a sealing member on four circumferences of the cedar material, and a height of 12 m is further applied on four circumferences of the sealing member.
A stainless steel material having a width of 50 mm and a width of 50 mm was arranged as a thickness control jig. After setting the heating plate to 200 ° C, the pressure is 50 kgf /
The hot platen was moved by cm ² , and the hot platen was moved until the movement was restricted by the thickness control jig to compress the wood material.

In this state, heating was continued for 10 minutes and 20 minutes, then cooling water was supplied to the hot platen, and after 5 minutes of depressurization, the consolidated wood material was taken out from between the hot plates. The cedar wood, which initially had a thickness of 30 mm, was compressed to 12 mm (compression rate 60%). Each of the final products thus obtained was boiled in a boiling tank for 2 hours and then absolutely dried, and the thickness of each was measured, and the radial thickness recovery rate was measured at the end portion and the central portion by the following formula. The results are shown in Table 1. Recovery rate = (thickness after boiling for 2 hours and absolute drying-thickness after consolidation) /
(Thickness before consolidation-thickness after consolidation) x 100%

[0031]

[Table 1]

[Discussion] As is apparent from Table 1, according to the heat treatment method for a wood material according to the present invention, a consolidated wood material having a smaller degree of recovery can be obtained in a short processing time (heating time). . In addition, since the wooden material to be treated is housed in the rigid container and placed on the heating plate and taken out after the treatment without arranging a thickness control jig or the like on the heating plate, the operation during the treatment is easy. In addition to the simplification, no deformation or breakage of the silicon packing and the like was found at all in all cases, and the treatment was uniform and complete even inside. In the case of Example 3, PE arranged on the surface
Due to the influence of the T sheet, it was easy to separate from the lid portion and the surface gloss was clear. Further, in the case of Example 4, fine irregularities were formed on the surface in contact with the silicone rubber sheet, and a product having high reality as a wood material and rich in design was obtained.

[0033]

EFFECTS OF THE INVENTION By using the heat treatment method of the present invention, it is possible to obtain a wood material sufficiently compacted to the central portion in a short time with a simple operation. In addition, the packing used during processing does not move or be damaged, and stable processing can be continued for a long time.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of a rigid container used for carrying out a heat treatment method for wood materials according to the present invention.

FIG. 2 is a diagram showing a state of the wooden material according to the present invention when it is consolidated.

FIG. 3 is a diagram showing another state when the wooden material according to the present invention is consolidated.

[Explanation of symbols]

1 ... Rigid container, 10 ... Container body, 20 ... Lid part, 20A
... sheet-like member, 30 ... elastic silicone packing, 40 ...
Wood material, 50 ... Hot plate, S ... Inner space of container body, W ... Width of inner space of container body, w ... Width of wood material, H ... Depth of inner space of container body, h ... Thickness of wood material It

Claims (3)

[Claims] 1. A rigid container having pressure resistance and heat resistance, which can be opened and closed, contains a wood material to be treated, and then heats the rigid container in a sealed state so that the wood material is contained in the rigid container. A heat treatment method for wood materials, characterized by compacting the crushed wood materials. 2. A rigid container comprising a container body and a lid portion, which has pressure resistance and heat resistance, contains a wood material to be treated in the container body, and after disposing the lid portion thereon, By heating the rigid container in a sealed state to heat-treat the wooden material housed in the rigid container, a method for heat treating a wooden material, between the surface of the wooden material to be treated and the bottom surface of the container body, or A sheet-like member is arranged on either or both of the front surface of the wood material to be treated and the back surface of the lid portion, and after the lid portion is installed in that state, the rigid container is sealed and heated. A heat treatment method for wood materials, which is characterized in that 3. The method for heat treating a wood material according to claim 2, wherein the sheet-shaped member is a silicon rubber sheet.