JP4353531B2 - Method for modifying wood - Google Patents

Description

  The present invention relates to a method for modifying wood.

  Wood has been used for limited applications such as building materials and furniture because it expands or contracts due to changes in moisture content and lacks flexibility. Incidentally, even when used as a building material, its use is not wide. For example, when used as a flooring material, the entire floor may be deformed by expansion / contraction due to a change in moisture content (humidity). Since there are many, hard and expensive kinds of wood with little change are used, and wood such as cedar is inexpensive but is not suitable as a flooring material. In addition, in order to prevent such a change due to humidity, processed wood into which resin is injected is implemented, but lacks dimensional accuracy due to a temperature change and is not suitable for floor heating. In addition, since wood lacks flexibility and elasticity, it has a low rate of absorbing external pressure. In particular, when a load is applied in the same direction as the heel, the wood is extremely fragile and often breaks.

  In this way, wood expands and contracts due to changes in moisture content and temperature, is weak in load resistance in the grid direction, and lacks flexibility and elasticity. .

  Therefore, the present invention has been proposed in order to solve the above-described problems of the wood, and can absorb external pressure, and thus can be used for a wider range of applications than previously limited. The purpose is to propose a new wood processing method.

The present invention has been proposed in order to achieve the above-described object, and the first invention (the invention described in claim 1) is a method in which wood is placed in a steam atmosphere of 0.1 to 0.5 MPa or under normal temperature and normal pressure. The softening step of softening by boiling at the same time, and the softened wood is sandwiched between one member and the other member in the atmosphere or under normal temperature and normal pressure, and both the one member and the other member or one member To drive the wood so that the volume of the wood is 1/3 to 2/3 or the cross-sectional area is 1/3 to 2/3. The compression holding step for maintaining the state and the one or the other member are driven to be separated from each other or the one member is driven to be separated from the other member in the atmosphere or at normal temperature and normal pressure, and the compression is performed. The treated wood during the softening process In addition to restoring the volume to a volume less than the volume, the wood is placed in an environment where the temperature in the atmosphere can be raised or the temperature of the atmosphere can be raised, the temperature is raised, and this state is maintained for a predetermined time. And a restoring and holding step.

  In this first invention, the wood to be processed is sufficient if it is used as a conventional wood such as coniferous cedar, oak, pine or hardwood birch, sen, zelkova, etc., and its type is limited. Is not to be done. Further, in the present invention, the shape of the wood to be processed is not particularly limited. However, considering the ease of a compression holding process, a restoration holding process, or a cutting process, which will be described later, it is formed into a rectangular parallelepiped shape. It is preferable to use one. And in this invention, the softening process, the compression holding process, and the decompression | restoration holding process are provided. And the said softening process can employ | adopt two means selectively. The first means is a method of softening wood in a water vapor atmosphere of 0.1 to 0.5 MPa. The softening temperature in the first method depends on the type of wood to be processed, but may be at least a temperature that can sufficiently soften the wood, and is usually in the range of 80 to 150 degrees Celsius. That is, the first softening means that is selectively employed in the softening step softens the wood in a steam atmosphere at a temperature of about 80 to 150 degrees Celsius at a pressure of 0.1 to 0.5 MPa. . Next, the second means is a method of boiling wood under normal temperature and pressure. The boiling temperature may be at least enough to soften the wood, and may be a temperature of about 80 to 100 degrees Celsius. In both cases of adopting the first means and the second means, the time required for the softening process may be appropriately set according to the type and volume of the wood to be processed. If the volume is small, it may be several tens of minutes, and if the volume is relatively hard and large, it may be several hours.

In the first invention, in the compression and holding step, first, the softened wood is compressed by the first means or the second means, and held in this compressed state for a predetermined time. In particular, the degree of compression of the softened wood is such that the softened wood is 1/3 to 2/3 of the volume of the original wood, or the cross-sectional area of the original wood is 1/3 to 2/3. As described above, the degree of compression is not uniform depending on the type of wood to be processed, and is set as appropriate. In addition, when compressing the softened wood in this way, for example, the softened wood is disposed between one member and the other member, and both the one and the other members are driven to And a method of compressing so that one member and the other member come close to each other, or placing softened wood on the other member such as a mounting table, and driving one member downward from above, It is possible to adopt a method of compressing while holding wood between the member and the other member. Moreover, as the compression method of the wood, not only the one and the other members, but also a method of compressing from four sides may be adopted when the wood is formed in a cubic shape as described above. Moreover, when the softened wood is compressed by any of the methods described above, it is necessary to maintain the compressed state for a predetermined time. Such holding time may also be held for about 10 to 30 minutes, depending on the type and volume of wood to be processed. By such a compression holding process, the cells constituting the softened wood are deformed and folded from the circular cross-section until then. In addition, such a compression holding process may be performed under the same atmosphere when water vapor is used in the softening process, or may be performed from the atmosphere to an atmosphere under a normal temperature and a normal pressure. . Moreover, this compression holding process WHEREIN: When the means boiled with water (hot water) is used in the said softening process, the softened wood may be taken out from this hot water, and you may compress and hold | maintain under normal temperature normal pressure.

  In the present invention, the restoration holding step is performed after the compression holding step described above. In this restoration and holding step, first, both the one member and the other member that have compressed the wood or the other member are driven so as to be separated from the held wood, or the mounting table that is the other member When wood is placed on the top, one member that has been lowered so far is raised to restore the compressed wood. However, the degree of restoration is at least until it becomes a volume smaller than the volume of wood before being processed, and preferably about 5% to 30% of the volume of wood before being processed. In addition, when restored to the same volume as the original volume, the cells of the wood will return to the original stable state, and there will be no effect described later. And the atmosphere which decompress | restores the compressed wood in this way can be performed in the same atmosphere as the atmosphere where the said compression holding process was made | formed. That is, in the softening step and the compression and holding step, when it is desired to use water vapor, it can be performed under the atmosphere, and when the compression and holding step is performed under normal temperature and normal pressure, the atmosphere as it is. It is also possible to do below.

  And in this invention, although this decompression | restoration holding process restores and holds the timber compressed in the way mentioned above, in this holding | maintenance state, it is necessary to make it raise from the temperature in the process so far. That is, when one of the one and the other member that has been compressed so far is separated from the wood, the wood is naturally restored, but the restored wood is about 5% to the volume of the wood before processing. It is necessary to hold the state so as not to restore more than about 30% (hold the volume to be less than the volume during the softening step), and the atmosphere in the holding state is higher than the temperature until then Must be hot. For example, when wood is softened at 120 degrees Celsius using water vapor in the softening process, or when boiled at 100 degrees Celsius, for example, about 130 to 170 degrees Celsius is appropriate. When the temperature is kept lower than the set temperature, the effects described below are not realized. The retention time of the wood restored under these temperature conditions is not uniform depending on the kind and volume of the wood and the temperature, but about 10 to 30 minutes is appropriate. And, through these various steps, the processed wood is left in an atmosphere of normal temperature and normal pressure, so that if the load from the outside is not applied, the volume is smaller than the wood before processing, The shape is held as processed wood having a volume slightly larger than the volume compressed in the compression holding step.

  The second invention (the invention according to claim 2) is characterized in that, in the first invention, the wood is compressed in a radial direction, a tangential direction or a synthetic direction thereof in the compression holding step. It is.

  In the second invention, the compression direction of the wood to be processed is limited to the radial direction, the tangential direction, or the combined direction thereof. That is, in the compression holding step, the wood is compressed in the stacking direction of the annual rings stacked in the radial direction (R direction), the tangential direction of the wood (T direction), or their combined direction (R direction + T direction). It does not include a method of compressing in the fiber direction (L direction) of wood.

  According to the wood modification method according to the first invention (invention 1), the cells constituting the wood are compressed by compressing and holding the softened wood, which is then performed. By raising the temperature in the restoration holding step, the compressed cells are restored partway and the state is fixed. And it is thought that elasticity is provided to each cell by such a process. This means that when the wood processed by the above process is cut into a bar shape having a thickness of 2 cm, a length of 15 cm, and a width of 3 cm and compressed by hand, it contracts greatly compared to unprocessed wood, and when pulled, It grows greatly compared to wood. Further, when the wood formed into the rod shape is supported at both ends, and a load is applied by pressing the central portion downward, the whole is greatly curved without cracking. Such a phenomenon is a phenomenon that occurs when the cells on the curved upper surface side contract while the cells on the lower surface side expand. Moreover, when the wood processed in this way is not cut into the above-mentioned stick shape, but cut into a thin plate with a thickness of about 0.5 mm, the thin diameter ( It can be rounded into a cylindrical shape so as to be about 3 mm. Considering such a phenomenon, it is considered that elasticity is imparted to each cell by the above process. In addition, such processed wood expands and contracts depending on the moisture content, but when both sides are fixed, the force is applied even if the wood itself expands due to the action of the cell bellows structure or spring structure. Absorbs, and as a result, does not cause warping or knuckles.

  Therefore, according to the present invention, the present invention can be used for a wider range of applications than previously limited applications. For example, it is possible to bond a wooden sheet obtained by processing the wood produced by the above processing method into a sheet shape around a cylindrical member having a radius of only a few millimeters, It is also possible to bond the sheets together. Further, in the case of a flooring material, even if an external force is applied, the external force can be absorbed, so that deformation like a conventional flooring material can be prevented.

  In the second invention (the invention according to claim 2), in the compression and holding step, the wood is compressed in the radial direction, the tangential direction, or the combined direction thereof. It is possible to effectively solve the conventional problem that cracks tend to occur between the two.

  Hereinafter, a wood processing method according to the best mode for carrying out the present invention will be described in detail in the order of steps with reference to the drawings.

  First, the wood is softened in a water vapor atmosphere of 0.1 to 0.5 MPa (softening step). In this softening step, when the wood is placed in a water vapor atmosphere of 0.1 to 0.5 MPa, the water vapor in the atmosphere is absorbed and the temperature of the wood itself is also increased, and the softening of the wood proceeds. Note that the temperature of the wood is heated to 80 to 150 degrees Celsius by leaving it in the atmosphere for several minutes to several tens of minutes. In addition, such a softening step is a predetermined high-temperature and high-pressure vessel provided with an internal space that can accommodate wood to be processed, and includes a water vapor generating device that discharges high-temperature water vapor into the internal space. Can be used.

  And when such a softening process is complete | finished, a compression holding process is then performed. In this compression and holding step, the wood 1 softened in the softening step described above is placed on, for example, a mounting table 2 (the other member constituting the present invention) shown in FIG. 2 is moved down (see (2) in FIG. 1), and the wood 1 is compressed by the mounting table 2 and the lifting drive member 3. . In addition, when the above-mentioned mounting base 2 and the raising / lowering drive member 3 are arrange | positioned in the high-temperature / high pressure vessel which is not illustrated, after softening the timber processed on the mounting base 2 on the said conditions, it is the state as it is. The wood 1 is compressed by lowering the elevating drive member 3 in the atmosphere. The compression direction for the wood 1 is the radial direction of the wood 1. The degree of compression is set so that the softened wood 1 has a volume of about 1/3 to 2/3 or a cross-sectional area of 1/3 to 2/3. Due to such compression, as shown in FIG. 2 (a), the cells of the wood 1 that have been in a nearly circular state until then become smaller in space as shown in FIG. 2 (b). And in this wood processing method, such a compressed state may be several minutes (about 10 to 20 minutes).

And when the said compression holding process is complete | finished, next, a decompression | restoration holding process is performed. This restoration holding step raises the elevating drive member 3 from the state shown in FIG. 1B by about 10% of the height of the wood 1 softened in the softening step, and the temperature in the atmosphere is in degrees Celsius. The elevation drive member 3 is fixed at that height. Due to the operation of the elevating drive member 3, the wood 1 that has been compressed so far is partially restored (restored) again and held at the position of the lower surface of the elevating drive member 3. This holding time may be about 10 to 30 minutes. And by such a restoration | restoration holding process, as shown in FIG.2 (b) until now, the cell of the wood 1 in which the space became small recovers a little as shown in the same figure (c). Then, when the restoration holding step is finished, the processed wood 1 is taken out from the atmosphere.

  The wood 1 obtained by the above-described steps is slightly smaller in volume than wood not subjected to such processing, but has the effects described below. The wood 1 shown in FIG. 3 is a grid plate in which a large number of annual rings are formed substantially in parallel in the length direction after being processed through the above-described steps and then cut into a rectangular bar. When both ends of the wood 1 are supported by the support members 4 and 5 and a load is applied from the upper center to the lower side as indicated by arrows, the above-described processing is not performed. Also breaks at the part of the annual ring formed. In particular, the degree of brittleness is more prominent as the moisture content of the wood decreases. However, the wood 1 that has been subjected to the processing described above is greatly curved as shown by the one-dot chain line in FIG. This can be understood that the upper surface side of the wood 1 shown in FIG. 3 is compressed while the lower surface side is expanded. Although not shown, when the wood 1 subjected to the processing is compressed, it is possible to reach a position close to the position compressed in the compression holding process, and when the wood 1 is expanded, the compression holding process is performed. Can be extended to a position close to the state before compression. From this, it can be understood that the wood 1 is given flexibility or elasticity within the above range.

  Therefore, according to the above-described wood processing method, it can be used in various fields that could not be used for conventional wood.

  In the above embodiment, the wood 1 formed into a rectangular parallelepiped shape is processed. However, the processing according to the present invention does not necessarily need to be performed after forming the rectangular parallelepiped shape, and the wood formed into an arbitrary shape is processed. It may be processed. Moreover, in the said embodiment, although the wood 1 was softened using water vapor | steam, the method of softening by boiling a wood under normal temperature normal pressure may be employ | adopted. Further, in the above-described embodiment, the compression holding step is also performed under the same atmosphere as that in the softening step. However, the compression holding step may be performed under normal temperature and normal pressure, and the compressed wood may be restored under normal temperature and normal pressure. (However, in the process of holding the restored wood, the temperature is about 150 degrees Celsius).

It is a front view which shows the processing method of this invention typically, (a) shows the state before compressing the softened wood, (b) shows the state currently compressed and held. (C) shows a state of being restored and held. It shows the change in the cells of the wood by the processing step, (a) shows the state before being compressed, and (b) shows the state after being compressed. Yes, (c) shows the state after restoration. It is a front view which shows typically the state where a load was made to act on wood and curved.

Explanation of symbols

1 Wood 2 Mounting table (other member)
3 Lifting drive member (one member)

Claims (2)

A softening step of softening wood by boiling in a steam atmosphere of 0.1 to 0.5 MPa or under normal temperature and normal pressure;
The softened wood is sandwiched between one member and the other member in the atmosphere or at normal temperature and normal pressure, and both the one member and the other member or one member is driven, whereby the wood becomes 1 / Compressing and holding step of compressing mechanically so that the volume is 3 to 2/3, or 1/3 to 2/3 in cross-sectional area, and holding this state for a predetermined period;
In the atmosphere or under normal temperature and normal pressure, the one and the other member are driven so as to be separated from each other, or the one member is driven so as to be separated from the other member, and the compressed wood is subjected to the softening step. The wood is placed in an environment that can be restored to a volume that is less than the volume in the environment, and the temperature in the atmosphere can be increased or the temperature of the atmosphere can be increased, and the temperature is raised, and this state is maintained for a predetermined time. And a restoring and holding step. A method for modifying wood, characterized by comprising:   2. The method for modifying wood according to claim 1, wherein in the compressing and holding step, the wood is compressed in a radial direction, a tangential direction, or a synthetic direction thereof.