JP3078451B2 - Wood processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a timber processing technique for expanding the range of use of timber, and more particularly to a method of converting low density wood such as thinned wood into high density wood. It relates to a method for processing wood.

[0002]

2. Description of the Related Art Thinned lumber generally grows quickly and is therefore weak, and its use range has a certain limit. In Japan, in particular, about 7
5% is cedar wood, which is a significant issue. Also,
Due to the large number of mountainous areas in Japan, there are many timber grown on steep slopes. There was a problem that was. That is, if correction of deflection or the like, equalization of the size of the original mouth and the end of the wood, and furthermore, taking out the roundness of the wood, and the like, there is a problem that the utilization range becomes narrower. Here, as a conventional technique for solving these problems, Japanese Patent Laid-Open No.
Wood processing methods such as those disclosed in Japanese Patent Application Laid-Open No. 97503/1995 and Japanese Patent Application Laid-Open No. 3-231802 have been known. (1) In the method disclosed in Japanese Patent Application Laid-Open No. 3-97503, after wood is absorbed, the wood is softened by high-frequency dielectric heating to deform the wood under pressure and fix the deformation. (2) On the other hand, the method disclosed in JP-A-3-231802 is
After the wood is absorbed and softened in a steam atmosphere, the wood is deformed under pressure and the deformation is fixed.

[0003]

In each of the prior arts described above, pressure deformation is performed after softening wood, and the deformation is fixed. However, according to such processing, the following problem occurs. That is, (1) Since the thinned wood actually cut has a length of at least about 4 m, equipment for softening the wood becomes large-scale, and it is difficult to perform simple and inexpensive processing. (2) In the softening treatment of wood by the high-frequency dielectric heating,
After deformation fixing, the wood expands due to water absorption or the like, and the fixing is not easily completed. (3) On the other hand, in the softening treatment of wood in the steam atmosphere, although completion of deformation fixation can be expected, simple and inexpensive treatment is still difficult. Therefore, an object of the present invention is to provide a method for processing wood, which can easily and inexpensively process the wood and fix the shape of the formed wood reliably. Another object of the present invention is to provide a method for processing wood, which can expand the range of use of wood by using high-density wood.

[0004]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a primary fixed product, which is softened, deformed after compression, and whose deformation is fixed, absorbs and expands again. The primary fixed product is deformed while being actively used, and the deformed shape is completely fixed to form a secondary fixed product.

That is, according to the first aspect of the present invention, a primary fixed product is obtained by compressing and holding water-absorbed and softened wood and fixing it in a predetermined compressed shape. The primary fixed product is inserted into a cylindrical mold to absorb water. The gist of the present invention is to form a shape in close contact with the mold by expanding the shape, fix the shape, and then remove the mold to obtain a secondary fixed product.

According to a second aspect of the present invention, in accordance with the first aspect of the present invention, wood which has been softened by absorbing water by boiling or immersing in hot water is compressed and held to form a primary fixed article fixed in a predetermined compressed shape. Is the gist.

[0007] The third aspect of the present invention is the first or second aspect.
The gist of the invention described above is that the step of fixing the shape after molding is performed by heating.

According to a fourth aspect of the present invention, in the third aspect of the invention, in the step of expanding water absorption, the primary fixed article is impregnated with a thermosetting resin.

[0009]

According to the first aspect of the present invention, since the wood is deformed and secondarily fixed by the mold, the wood of a uniform shape faithful to the mold and the fixing thereof are performed.

According to the second aspect of the present invention, the softening of wood by water absorption can be carried out by a simple method such as boiling or immersion in warm water, which does not require large-scale equipment.

According to the third aspect of the present invention, a good shape is fixed while the residual stress in the primary fixed product is reduced and removed by heating.

According to the fourth aspect of the present invention, the thermosetting resin impregnated in the primary fixed article is cured by heating, so that the dimensional stability of the secondary fixed article having high density is improved.
Further, the strength of the secondary fixed product further increases.

[0013]

【Example】

Embodiment 1 Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings. First, wood 1 used in this example is prepared (see FIG. 2). The dimensions of the wood 1 may be of an appropriate size, but in this example, the average diameter is 12.5 cm and the length is 20.
cm of cedar thinned wood was used. In addition, wood 1 used for processing
The tree species is not particularly limited, but soft or low-density wood such as cedar or thinned wood is preferable in consideration of ease of processing. Thus, the wood 1 is subjected to the softening treatment K1. This softening treatment K1 is for absorbing the water to the wood 1 to soften the tissue. In the present embodiment, the wood 1 was softened by immersion in hot water in consideration of simplicity.
The amount of water absorption in the softening treatment K1 is not particularly limited, but it is preferable to absorb water above the fiber saturation point in consideration of softening, and it may be made to be saturated until it becomes saturated. There is no particular limitation on the boiling or immersion time, and it is sufficient that the wood 1 is softened.
In the present example, water absorption and softening were performed by immersing in hot water of 75 ° C. for 2 hours. Note that the softening treatment K1 can also be performed by means for bringing water vapor into contact with the wood 1 or means for subjecting the wood 1 to high-frequency dielectric heating.

Next, compression processing K2 is performed on the wood 1 that has been softened K1. The die 2 and the press 3 are used for the compression process K2 (see FIG. 3). In the compression process K2, the wood 1 is compressed and deformed. The compression process K2 is as follows.
This is a step for promoting the water-absorption expansion process K5 described below, and the degree of compression is not particularly limited. The mold 2 compresses the entirety of the wood 1 in the direction of reducing the width of the annual ring, that is, in the direction perpendicular to the axis L, and is at least as long as the length of the wood 1 and has a concave pressing surface. It consists of a pair of upper and lower dies having upper and lower dies. The upper die and the lower die are attached to the pressing ram of the press machine 3 with their pressing surfaces facing each other. In addition, as the press machine 3, an appropriate model capable of pressing the wood 1 can be used. Thus, the softening treatment K
The obtained wood 1 was sandwiched between the pressing surfaces of the upper die and the lower die, and gradually pressed by a press machine to compressively deform the wood 1 into a square shape with one side of 82 mm (see FIG. 3 (B)). ).

After performing the compression process K2, as shown in FIG. 3B, the primary fixation K3 is performed by maintaining the compressed state as it is. The primary fixation K3 is a step for promoting the water-absorption expansion process K5 described later, and the time for compressing and holding is not particularly limited. In the present example, the temperature was held at room temperature for 3 hours. After the compression is held for a predetermined time, the primary fixing K3 is ended. That is, the press pressure of the press machine is released, the upper mold and the lower mold are opened, and the wood subjected to the treatment of the primary fixing K3, that is, the primary fixed product 1a is obtained. The wood that has been released from the press pressure slightly returns in accordance with the compression amount and the compression time, and the primary fixing K3 is completed. In the wood of the present example, one side returned by 3 mm, and a square primary fixed product 1a having a cross section of 85 mm was obtained.

Next, as shown in FIG. 1A, the primary fixed product 1a is inserted into the mold 4 (K4). The mold used for the mold insert K4 is for making the secondary fixed product 1b having a stable shape by using the expansion of the primary fixed product 1a.
An inner diameter that is somewhat larger than the diameter of a and is at least as long as the primary fixed article 1a is used. The shape of the mold 4 is not particularly limited, and may be arbitrarily selected according to the finally obtained shape. The mold 4 is formed of a highly rigid metal such as a steel material, and has a thickness sufficient to withstand the expansion of the primary fixed product 1a. In this embodiment, the inner fixed section has a square shape with a side of 88 mm and a length of the primary fixed product 1a.
And a steel mold having a thickness of 10 mm.

Next, the primary fixed product 1a inserted into the mold 4 is subjected to a water-absorbing expansion process K5. The expansion process K5 is performed by allowing the primary fixed product 1a inserted into the mold 4 to absorb water. The means for absorbing water is not particularly limited, and it is sufficient that the expansion of the primary fixed article 1a is sufficiently promoted. Specifically, for example, a method of boiling, a method of immersing in hot water, a method of using steam, and the like can be adopted.In this embodiment, in consideration of the simplicity of treatment, the method of immersing in hot water was used. . Here, the amount of water absorption is not particularly limited, and it is sufficient that the expansion of the primary fixed article 1a is sufficiently promoted. In this example, as shown in FIG. 1B, the mold into which the primary fixed article 1a was inserted was immersed in hot water at 60 ° C. for 10 minutes to expand the primary fixed article 1a.

Further, in the water absorption expansion treatment K5, the primary fixed article 1a may be impregnated with a thermosetting resin. That is,
In order to further improve the shape fixation of the secondary fixed product, it is also possible to impregnate the water used for water absorption in the water absorption expansion treatment K5 with an aqueous phenol resin solution. Here, the aqueous solution can be appropriately impregnated in the secondary fixation K7 to select an appropriate concentration capable of strengthening the secondary fixation product 1b. In this embodiment, a 20% aqueous phenol resin solution was used. As the thermosetting resin that can be used in the water-absorbing expansion treatment K5, a thermosetting resin having a relatively low molecular weight that is easily impregnated into wood, such as a urea resin or a melamine resin, may be used in addition to the phenol resin. Good. This corresponds to the fourth aspect of the present invention.

The primary fixed article 1a is brought into close contact with the inner wall surface of the mold frame 4 due to water absorption expansion, and the primary fixed article is formed into a shape conforming to the mold frame 4 (K6) by the internal pressure caused by the expansion. Next, secondary fixing K7 is performed in a state where the primary fixed product 1a is tightly inserted into the mold frame 4. The secondary fixing K7 is a process for relaxing and removing the residual stress inside the primary fixed product to stabilize and fix the shape of the processed wood. As the secondary fixing means, for example, a heat treatment under pressure with steam or a heat treatment under normal pressure can be performed. In the present example, secondary fixing was performed by heating wood to a predetermined temperature under pressure. The secondary fixing K7 by heating corresponds to the third aspect of the present invention. Here, the heating conditions necessary for completely fixing the shape formed under normal pressure are as shown in the graphs I to III in FIG. 4 as a result of the test. That is, as shown in graph II of FIG.
For example, at a temperature of 180 ° C., the return rate becomes 0 by heating for 20 hours, and complete secondary fixing is performed. Further, at a temperature lower than 180 ° C., the return rate does not become 0 or it takes a long time to make it 0. Therefore, the temperature for practical secondary fixing is preferably 180 ° C. or more (FIG. 4). Graphs I-III). In this embodiment,
It was fixed by heating at 180 ° C. for 20 hours. Further, in the present embodiment, the processing is performed by one heating, but the processing can be performed by alternately repeating the heating and the cooling several times.
For example, by heating at a temperature of 120 ° C. and then cooling, and repeating the process about seven times, the shape can be completely fixed. In the present embodiment, pheno-
The primary fixed article 1a is impregnated with the aqueous resin solution, but in the step of secondary fixing K7 by heating, the phenol resin filled in the wood tissue is hardened and the dimensional stability of the shape by the secondary fixing K7 is improved. did.

After the completion of the secondary fixing, the process of removing the mold K8 is performed. Since the secondary fixed product 1b in the secondary fixing K7 is in close contact with the mold 4, in the present embodiment, the mold 4 is heated and expanded and loosened before removing the secondary fixed product 1b (FIG. 5 ( A) (B)). In the case where the mold 4 is made of a divided body having a symmetrical concave surface by dividing the cylindrical body into two parts,
By removing the connection, the secondary fixed product 1b can be taken out (not shown). Thus, a secondary fixed product 1b of this example was obtained. This secondary fixed product 1b was formed along the inner surface shape of the mold frame 4, had a wood structure having a density higher than that of the original wood 1, and had a uniform and beautiful finish. This secondary fixed product was stable in shape, and no subsequent deformation was observed.

(Embodiment 2) Next, Embodiment 2 of the present invention will be described with reference to the drawings. Note that the present embodiment relates to rounding of wood. First, after softening the wood 1 K1,
Compression processing K by pressing machine so that the cross section becomes square
Do 2 Here, the softening process K1, the compression process K2, the shape of the mold, and the like were performed in the same manner as in Example 1. Next, as shown in FIGS. 7A and 7B, the wood 1c subjected to the compression process K2 is rotated by 90 ° about the axis L so that each vertex of the square cross section is compressed. , And compressed again by the press machine 3. As a result, wood 1d having an octagonal cross section is obtained.

Next, the primary fixing K3 is performed under the same conditions as in the first embodiment. Next, the primary fixed product 1e that has been subjected to the primary fixing K3 is inserted into the cylindrical mold 4a (mold insertion K4). The inner diameter of the mold is not particularly limited as long as it has a predetermined margin with respect to the primary fixed product 1e, and can be arbitrarily selected within a range where the wood can expand. Then, the primary fixed product 1e is expanded while absorbing water while being inserted into the mold 4a (expansion process K5, FIG. 8A).
(B)). The water absorbing means and the like are the same as in the first embodiment.

Next, the wood is brought into close contact with the inner wall surface of the mold due to the expansion of the primary fixed article 1e, and the wood is formed into a perfect circular shape in conformity with the mold by the internal pressure due to the expansion (formation K).
6).

Thereafter, secondary fixing K7 and secondary fixing releasing K8 are performed. The method and conditions of both are the same as those in the first embodiment. That is, after the mold is heated and expanded as shown in FIG. 9A, the secondary fixed product 1f shown in FIG. 9B is taken out from the mold 4a. Thus, according to the second embodiment, a secondary fixed product 1f having a circular cross section and almost the same diameter was obtained. This secondary fixed product 1f was stable in shape, and no subsequent deformation was observed. In the second embodiment, a primary fixed product 1e having an octagonal cross section is obtained by using an upper die and a lower die having a 90 ° pressing surface twice, and this is inserted into a cylindrical mold 4a to form a columnar member. In the compression treatment of the primary fixed product, a column-shaped primary fixed product was obtained using a split mold having a pressing surface of a concave curved surface having a semicircular cross section, and this was fixed to a cylindrical shape. Column-shaped secondary fixed product 1
f may be obtained.

[0025]

According to the first aspect of the present invention, since the molding and the secondary fixing of the wood are performed by the mold, the reinforcement by the densification of the wood, the correction of the deflection of the wood, the original mouth and the end of the wood are achieved. It is possible to easily and surely make the same size, make the wood round and the like. Further, unlike the related art, a large-scale apparatus is not required, and it is possible to mass-produce wood of the same shape at low cost. According to the second aspect of the invention, it is possible to perform simple primary fixing, and unlike the related art, a large-scale device is not required, and primary fixing can be performed at low cost. According to the third aspect of the present invention, simple secondary fixing can be performed, and secondary fixing can be performed at low cost. According to the invention of claim 4, the strength of the secondary fixed product is further increased and the dimensional stability of the secondary fixed product is improved.

[Brief description of the drawings]

FIGS. 1A and 1B are a process diagram (A) of inserting a primary fixed product into a mold and a process diagram (B) of absorbing and expanding the primary fixed product inserted into the mold.

FIG. 2 is a view showing wood before processing in Example 1.

FIG. 3 is a process diagram of a compression process, in which (A) is before pressing,
(B) shows the state after pressing.

FIG. 4 is a graph showing heating conditions in a secondary fixing process.

FIGS. 5A and 5B are process diagrams of removing the mold, FIG. 5A is a diagram illustrating a heated mold shape, and FIG. 5B is a diagram illustrating the removed secondary fixed product.

FIG. 6 is a process chart of wood processing in Example 1.

FIGS. 7A and 7B are diagrams showing a compression processing step of Example 2, wherein FIG. 7A is a diagram before pressing and FIG. 7B is a diagram after pressing.

FIG. 8A is a diagram showing a state in which the primary fixed product is inserted into a mold frame according to the second embodiment, and FIG.
It is.

FIG. 9 is a process chart of removing the mold of the secondary fixed product according to the second embodiment.
(A) is a figure which shows the shape of a heated mold, (B) is a figure which shows the secondary fixed article which removed the mold.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Wood 1a Primary fixed article 1b Secondary fixed article 4 Formwork 4a Cylindrical formwork

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-77203 (JP, A) JP-A-5-50409 (JP, A) JP-A-4-201503 (JP, A) JP-A-5-201503 318411 (JP, A) JP-A-7-60710 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B27K 1/00-5/06

Claims (4)

(57) [Claims] 1. A primary fixed product in which water-absorbed and softened wood is compressed and held to be fixed in a predetermined compressed shape, and the primary fixed product is inserted into a cylindrical mold and expanded while absorbing water. A method for processing wood, comprising forming a shape in close contact with the substrate, fixing the shape, and removing the mold to obtain a secondary fixed product. 2. The method for processing wood according to claim 1, wherein the wood which has been softened by absorbing water by boiling or immersing in warm water is compressed and held to form a primary fixed product fixed in a predetermined compressed shape. . 3. The method for processing wood according to claim 1, wherein the step of fixing the shape after molding is performed by heating. 4. The method for processing wood according to claim 3, wherein in the step of expanding water absorption, the primary fixed article is impregnated with a thermosetting resin.