JP2008173925A - Densification processing method and pressurization densification apparatus of natural raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for easily densifying without imparting damage to fibers or connective tissues of fibers by pressurizing and compressing natural raw materials comprising fiber tissues oriented in the axial direction and other tissues such as wood materials and bamboo materials two dimensionally or in axialy symmetrical manner from a direction vertical to an axial direction using hydraulic pressure. <P>SOLUTION: In the pressurization and densification processing method of the natural raw materials, (2)the natural raw materials such as the wood materials or the bamboo materials including the axial directional fiber tissues in the tissues is dried, thereafter (3)they are housed in a cylindrical high-pressure container while aligning the axial directions, they are densified by pressurizing and compressing by the hydraulic pressure from the direction perpendicular to the axial direction of the natural raw materials two dimensionally or in the axially symmetric manner, then (4) they are solidified by subjecting them to heating processing. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention compresses two-dimensionally or axially symmetrically a natural material including an axial fiber structure in a tissue such as wood or bamboo using a fluid pressure from a direction perpendicular to the axial direction. The present invention relates to a densification method and a pressure densification device therefor.

  In recent years, effective use of natural resources has been regarded as important from the viewpoint of environmental protection, and its use as a member of automobiles, home appliances, and the like is being advanced. In these fields, the use of natural kenaf fibers in the form of a composite material by adding polylactic acid as a matrix is being studied, but wood and bamboo are made of strength due to their low density, which is their drawback. By correcting the shortage, use in a form close to that is also being studied.

  In the latter case, a densification process is basically required, and research and development for this purpose has been conducted and various processes have been proposed. As the simplest processing method, after softening wood in a high-pressure steam atmosphere, a method of compression molding / fixing treatment under high-pressure conditions (for example, refer to Patent Document 1), A method of applying pressure after high frequency dielectric heating such as microwave heating (see, for example, Patent Document 2) has been proposed. These methods densify the whole wood.

  In addition, it is preferable to manufacture a light and hard material only on the surface of the table top plate, the step plate of the staircase, and the floor material in order to prevent scratches, and in recent years, a method of densifying (hardening) only the surface layer. Has been put to practical use or proposed. Basically, a method of heating only the surface portion with a hot plate press to soften and pressurizing is adopted, but a method using a hot press roll press (see Patent Document 3) has also been proposed. Furthermore, in the case of relatively low density wood such as cedar and cypress, which are expected to be used effectively, in order to make a laminated wood by densifying a plurality of small diameter trees with an adhesive from the viewpoint of using thinned wood, There has been proposed a method of performing pressure treatment and compression after steam treatment under high temperature and pressure (see Patent Document 4).

In many of these conventional techniques, pressure compression is performed by pressing in one direction with a press or roll, but fluid such as gas or water is pressurized and fluid pressure is applied via an elastic body such as rubber. A method of compressing in a lateral direction has also been proposed. In the old British patent in the 1910s (see Patent Document 5), wood heated to 90 to 150 ° C. was fluidized at a pressure of at least 200 kg / cm ² (≈20 MPa). A method of compressing using asphalt has been proposed.

  Next, a wood pressure processing apparatus according to another prior art will be described with reference to FIG. FIG. 8 is a schematic cross-sectional view of an apparatus for pressure treatment of wood according to an embodiment of the prior art. According to this prior art, elongated wood elements 25a, 25b, 25c having a rectangular cross section mainly including plate materials are placed in the high-pressure vessel 21 and the wood elements 25a, 25b, 25c are passed through the diaphragm 24 and further airtight casing material. 23, a method of densifying with pressure applied by a pressure medium has been proposed, and a specific surface is formed in a shape along the guide surface by using a member having guide surfaces 26a and 26b. Has also been proposed (see Patent Document 6).

These conventional techniques are characterized by pressurizing the test material in a heated state, and the heat treatment is performed immediately before the pressure densification treatment, or the pressure treatment itself is performed at a high temperature of 120 to 200 ° C. It is characterized by that. In addition, because wood and bamboo have a low thermal conductivity, heating takes a long time, and in order to shorten this, in many cases, steam or pressurized steam is used for heating. It is not significantly shortened. Moreover, it has the fault that it can apply only to board | plate materials, such as a flooring, with a hot press roll and the press on a flat plate.
JP-A-3-231802 Japanese Patent Laid-Open No. 3-97503 Japanese Patent Publication No. 4-3722 JP-A-7-32325 British Patent GB100.792 Japanese National Patent Publication No. 11-503377

  Furthermore, in pressure densification by isotropic pressure, the fluid pressure is compressed not only in the direction perpendicular to the direction of the fibers of wood and bamboo, but also in the axial direction, which is the direction of the fibers. Since the elastic modulus is as large as 150 to 300 GPa, it is only elastically deformed at a normal pressure of 100 to 1000 MPa and is restored after decompression. In fact, only the pressure in the direction perpendicular to the axial direction contributes to densification. Furthermore, because the fibers or the connective structure of fibers that are aligned in the axial direction, which is the cause of the strength development in the axial direction of wood and bamboo, are damaged, the best strength characteristics are not always obtained, and the purpose is to use as a strength member In this case, there is a disadvantage that it is not effective.

  Therefore, an object of the present invention is to use a natural material composed of a fiber structure oriented in the axial direction and other structures, such as wood and bamboo, from a direction perpendicular to the axial direction by using fluid pressure. An object of the present invention is to provide a pressure densification method and a pressure densification device that can be easily densified without damaging the fibers or the connective tissue between the fibers by subjecting them to pressure compression in a symmetrical or axially symmetrical manner.

  In order to achieve the above object, the means adopted by the pressure densification processing method of the natural material according to claim 1 of the present invention is a natural material containing an axial fiber structure in the tissue such as wood or bamboo. After drying treatment, it is stored in a cylindrical high-pressure vessel with its axial direction aligned, and is compressed and compressed in a two-dimensional or axisymmetric manner by fluid pressure from a direction perpendicular to the axial direction of the natural material. And then fixed by heat treatment.

  Here, the meaning of “vertical” or “axisymmetric” may be substantially vertical or substantially axially symmetric, and need not be completely vertical or axially symmetric. In addition, the meaning of “alignment” in this case should be almost uniform, and it is not necessary to completely align.

  The means adopted by the pressure densification treatment method for a natural material according to claim 2 of the present invention is the pressure densification treatment method for a natural material according to claim 1, wherein the drying treatment is performed at a temperature of 85 to 120. It is characterized in that it is carried out in the atmosphere of ° C.

  The means adopted by the pressure densification treatment method for a natural material according to claim 3 of the present invention is the pressure densification treatment method for a natural material according to claim 1 or 2, wherein the fluid pressure is 30 to 30. It is characterized by being 400 MPa.

  The method adopted by the pressure densification treatment method for a natural material according to claim 4 of the present invention is the pressure densification treatment method for a natural material according to any one of claims 1 to 3. In the above, the heat treatment is performed at a temperature of 150 to 180 ° C.

  The means adopted by the pressure densification treatment method of a natural material according to claim 5 of the present invention is the pressure densification treatment method of a natural material according to any one of claims 1 to 4. The fluid pressure is compressed and compressed two-dimensionally or axisymmetrically from a direction perpendicular to the axial direction of the natural material through an elastic body that is attached to the inner surface of the cylindrical high-pressure vessel and contains the fluid pressure. Thus, it is characterized by being densified.

  The method adopted by the pressure densification processing method of a natural material according to claim 6 of the present invention is the pressure densification processing method of a natural material according to any one of claims 1 to 5. The natural material is divided into a plurality of parts, and a rigid template is sandwiched between the divided composite materials, and is compressed and densified.

  The means adopted by the pressure densification device for natural materials according to claim 7 of the present invention is that a cylindrical membrane comprising an inner surface of a cylindrical high-pressure vessel and an elastic body attached to the inner surface of the cylindrical portion. A pressurized space is formed by the outer surface, a pressurized fluid introduction hole for introducing a pressurized fluid into the pressurized space is provided, and a pressurized compression force by the pressurized fluid is transmitted to the inside of the cylindrical membrane. Therefore, a cylindrical perforated elastic body having a perforated portion in the axial direction is accommodated, and a natural material made of wood, bamboo, or the like is loaded into the perforated portion of the cylindrical perforated elastic body. The natural material is configured to be compressed and compressed through the cylindrical perforated elastic body two-dimensionally or axisymmetrically from the direction perpendicular to the axial direction by the fluid pressure introduced into the pressure space. It is characterized by.

  The natural material pressure densification device according to claim 8 of the present invention employs the natural material pressure densification device according to claim 7, wherein the cylindrical perforated elastic body is perforated. The part is composed of a plurality of holes.

  According to the pressure densification processing method of a natural material according to claim 1 of the present invention, a cylindrical high pressure vessel is obtained after drying a natural material including an axial fiber structure in a tissue such as wood or bamboo. It is stored in the same axial direction inside, and is compressed and compressed by fluid pressure two-dimensionally or axially symmetrically from the direction perpendicular to the axial direction of the natural material, and then fixed by heat treatment. Therefore, the pressure densification treatment can be performed in a short time without preventing the shrinkage deformation and destroying the fiber structure, and as a result, a high-strength natural compression composite material can be obtained.

  Moreover, according to the pressure densification processing method of the natural material according to claim 2 of the present invention, since the drying treatment is performed in the atmosphere at a temperature of 85 to 120 ° C., the natural material is densified close to the true density. In addition, the remaining bound water contributes to easier deformation during pressurization.

  Furthermore, according to the pressure densification treatment method for a natural material according to claim 3 of the present invention, since the fluid pressure is 30 to 400 MPa, the density is 70% or more of the true density of the natural material. Is achieved.

  Still further, according to the pressure densification treatment method for natural materials according to claim 4 of the present invention, since the heat treatment is performed at a temperature of 150 to 180 ° C., generation of carbon and oxidation phenomenon due to thermal decomposition of lignin. Blackening due to is prevented.

  Moreover, according to the pressure densification processing method for a natural material according to claim 5 of the present invention, the fluid pressure is attached to the inner surface of the cylindrical high-pressure vessel via the elastic body that contains the fluid pressure. Since the pressure is compressed and densified two-dimensionally or axisymmetrically from the direction perpendicular to the axial direction of the natural material, the fluid pressure can be reliably transmitted to the natural material.

  Furthermore, according to the pressure densification processing method for a natural material according to claim 6 of the present invention, the natural material is divided into a plurality of parts, and a template having rigidity is provided between the divided composite materials. Since the material is pressed and compressed and densified, the shape of the natural material is touched to the template, and the natural material is of course shaped without distorting the template. I can do it.

  On the other hand, according to the pressure densification apparatus for natural materials according to claim 7 of the present invention, the cylindrical membrane inner surface comprising a cylindrical portion inner surface of a cylindrical high pressure vessel and an elastic body attached to the inner surface of the cylindrical portion. A pressurized space is formed by the outer surface, a pressurized fluid introduction hole for introducing a pressurized fluid into the pressurized space is provided, and a pressurized compression force by the pressurized fluid is transmitted to the inside of the cylindrical membrane. Therefore, a cylindrical perforated elastic body provided with a perforated portion in the axial direction is accommodated.

  Then, a natural material made of wood or bamboo is loaded into the perforated portion of the cylindrical perforated elastic body, and the natural material is perpendicular to the axial direction by the fluid pressure introduced into the pressurized space. Since it is configured to compress and compress two-dimensionally or axially symmetrically through the cylindrical perforated elastic body from any direction, a configuration capable of compressing and compressing without damaging the fiber structure of the natural material Is possible.

  According to the pressure densification device for natural materials according to claim 8 of the present invention, since the perforated portion of the cylindrical perforated elastic body is composed of a plurality of holes, the plurality of perforated portions. By loading each of the natural materials, a plurality of natural materials can be compressed at the same time.

  A natural material densification treatment method and pressure densification apparatus according to Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a process diagram showing steps of a natural material densification treatment method according to Embodiment 1 of the present invention, and FIG. 2 is a schematic diagram of a natural material pressure densification apparatus according to Embodiment 1 of the present invention. FIG. 3 is a schematic cross-sectional view showing an arrow XX in FIG. 2 according to the first embodiment of the present invention.

  In FIG. 1, the pressure densification method for a natural material according to Embodiment 1 of the present invention is such that a natural material such as wood or bamboo is first accommodated in a pressure densification device described later. In addition to cutting, the outer shape is also adjusted (step 1). Next, a drying process is performed in the atmosphere using a drying furnace (step 2). The drying temperature is in the range of 85 to 120 ° C., and the holding time at this temperature depends on the dimensions of the natural material, particularly the thickness. For thin materials such as bamboo, the thickness is 10 hours or more. For wood having a thickness of 50 mm or more, it is preferable to carry out a drying treatment for 12 to 48 hours.

  In addition, when the said drying temperature exceeds 120 degreeC, since partial alteration of a natural material will arise, it is unpreferable. The purpose of the drying treatment is to remove excess moisture that hinders densification, the water vapor pressure is sufficient, and the temperature at which the valve structure that controls water evaporation is softened is 120 ° C. .

  By such a drying process, the water in the conduit in a closed state is also removed from the water contained in the wood / bamboo tissue, so-called free water. If the water in the closed space is not removed by performing this drying process, even if pressure compression is performed, the portion including the water is not compressed, and thus sufficient densification cannot be achieved.

  In addition, wood and bamboo are composed of cellulose constituting the fiber structure and other hemicelluloses and lignin, but it is possible to partially decompose and soften the lignin that acts as an adhesive by heating by this drying treatment. Become. Since some of the softened lignin does not harden even when it returns to room temperature, it can be freely deformed by pressure even during pressure densification treatment.

The wood / bamboo material in such a state has been densified to a high density even under pressure at room temperature, and can be easily said to be the true density of wood by pressing at a pressure of 100 MPa or more. It is densified to a density close to ³ kg / m ³ . Incidentally, wood that has not been subjected to a drying treatment at a temperature of 85 to 120 ° C., for example, commercially available cedar wood (normal density of about 0.35 × 10 ³ kg / m ³ ) or cypress wood (normal density) In the case of 0.45 × 10 ³ kg / m ³ ), the density is only densified to (0.9 to 1.05) × 10 ³ kg / m ³ even when the pressure is increased to 1000 MPa at room temperature.

  This is because a part of the free water remains confined in the closed space, so that even if it is in a compressed state at a pressurized high pressure, it returns to its original state after depressurizing to atmospheric pressure. It is done. The amount of water contained in the original wood or bamboo varies depending on the presence or absence of natural drying and the storage state, and is in the range of 10 to 130%, but is about 5 to 10% after the drying treatment. This residual moisture is bound water combined with components such as lignin and cellulose, and contributes to facilitating deformation during pressure treatment. If the temperature of the drying process is increased to 150 ° C. or higher, even this combined water is removed, which is not preferable.

  Next, natural materials such as wood and bamboo that have been dried under such conditions are then compressed and compressed two-dimensionally or axisymmetrically with fluid pressure using a pressure densification device described later. (Step 3). The pressure for pressure densification depends on the density after treatment, but a pressure of 30 to 400 MPa is sufficient to increase the density to 70% or more of the true density.

  If the pressure is less than 30 MPa, sufficient densification cannot be achieved, and even if the pressure exceeds 400 MPa, the effect does not change much. The pressure is in a numerical range where a pressure of about 100 to 200 MPa is even better. Further, since the wood has viscoelastic properties, a short time of about several seconds is insufficient, but if it is 1 minute or longer, there is no problem in densification.

  The wood and bamboo that have been pressed and densified in this way are in an unstable state where the size and shape cannot be maintained as they are, and the densified structure returns to a restored state to some extent depending on the atmospheric conditions. End up. For example, if a pressure-densified wood is immersed in boiling water for several hours or more, it will swell considerably. In order to fix the densified state after the pressure densification treatment, it is known that heat treatment is effective in a temperature range of 150 to 200 ° C. The treatment time is required to be about 24 hours. However, when many woods are kept at 180 ° C. or more for 24 hours, blackening occurs due to generation of carbon or oxidation due to thermal decomposition of a part of lignin.

  In order to prevent such blackening, in the present invention, it is recommended to perform a fixing heat treatment (step 4) in which heating is performed in a temperature range of 150 to 180 ° C. after the densification treatment. The heating and holding time is 24 to 36 hours at a processing temperature of 150 ° C, 12 to 24 hours at a temperature of 170 ° C, and 6 to 12 hours at a temperature of 180 ° C. Therefore, the holding time is not limited. If the processing temperature is less than 150 ° C, it takes too much processing time. If the processing temperature is higher than 180 ° C, blackening and strength reduction occur, which is not desirable.

  Further, it is also known that combining steam heating is effective as a method for performing treatment in a short time, and can be adopted in the present invention. In this case, if the temperature is 180 ° C., it can be fixed in about 5 minutes. Finally, the natural heat-treated material is subjected to a finishing process for adjusting the shape and dimensions of the final product or intermediate product (step 5).

  As shown in FIG. 2, a pressure densification apparatus according to Embodiment 1 of the present invention for performing the pressure densification process (step 3) includes a cylindrical portion 11 having pressure resistance, and the cylindrical portion 11 A high-pressure vessel comprising a ring-shaped upper lid 12a and an upper plug 12b for sealing the upper end, and a ring-shaped lower lid 13a and a lower lid 13b for sealing the lower end of the cylindrical portion 11 is provided. Reference numeral 20 denotes a press frame that presses and supports the ring-shaped upper lid 12a and the upper plug 12b from above.

  And the pressure densification apparatus 10 which concerns on Embodiment 1 of this invention consists of an elastic body which has the ear | edge part 15a at both ends so that the pressurization space 14 may be formed in the cylindrical part 11 inner surface of this high pressure container. A cylindrical membrane 15 is mounted, and inside the cylindrical membrane 15, as shown in FIG. 3, in order to transmit the pressurized compression force by the pressurized fluid to the columnar wood 16 that is a natural material. A cylindrical perforated elastic body 17 having a perforated portion 17a having a circular cross section provided in the axial direction is accommodated.

  At the same time, the cylindrical wood 16 can be loaded into the perforated portion 17a of the cylindrical perforated elastic body 17. When a pressurized fluid is introduced into the pressurized space 14 and the cylindrical membrane 15 is pressurized, the columnar wood 16 is two-dimensionally or axially symmetrical from a direction perpendicular to the axial direction. It is configured to be compressed under pressure.

  That is, in the pressure densification apparatus 10, the pressure space 14 formed by the outer surface of the cylindrical membrane 15 and the ear portions 15a at both ends and the inner surfaces of the cylindrical portion 11 is pressurized by a pressure pump (not shown). The pressurized fluid thus introduced is introduced through a pressurized fluid introduction hole 14 a, and the columnar wood 16 is two-dimensionally transmitted through a columnar perforated elastic body 17 disposed inside the cylindrical membrane 15. Alternatively, it receives a pressure and compression force in the centripetal direction in an axisymmetric manner. The cylindrical wood 16 is contracted in the centripetal direction by the pressure and compression force, and this deformation is maintained in the deformed state except for the elastic recovery even if the pressure is removed.

  In many coniferous trees such as cedar and cypress, the structure of wood is composed of a dense dark-colored tissue part represented by annual rings and a sparsely light-colored tissue part, and is not uniform. For this reason, when pressure is applied to wood having a circular cross section, the sparse light-colored portion is compressed more, and the cross-sectional shape becomes a non-circular irregular shape.

  In addition, when the portion where the branches are taken out of the wood is collected and formed as the cylindrical wood 16, the traces from which the branches are removed are compressed because the axial structure of the branches is directed in the radial direction. However, the amount of shrinkage is reduced, and after pressurizing, the shape protrudes from the surroundings. Therefore, the cylindrical perforated elastic body 17 is easily damaged, and in order to prevent this, it is preferable to dispose the cushioning material 18 on the outer periphery of the cylindrical wood 16.

  The columnar perforated elastic body 17 disposed between the cylindrical membrane 15 and the columnar wood 16 has a function of preventing the cylindrical membrane 15 from being damaged by this distorted deformation. Of course, since the diameter of the columnar wood 16 differs depending on the material, the columnar perforated elastic body 17 also has a function of being able to cope with the shape even if the size and shape are slightly different. . The role of the columnar perforated elastic body 17 disposed inside the cylindrical membrane 15 is very important. As shown in the following Embodiments 2 to 5, the shape and number of natural materials to be pressure-treated Various measures can be taken depending on the situation.

  Next, a densification treatment method and pressure densification apparatus for natural materials according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 4 is a schematic cross-sectional view according to Embodiment 2 of the present invention and showing an arrow XX in FIG. However, the difference between the second embodiment of the present invention and the first embodiment is that there is a difference in the form of the natural material and the shape of the cylindrical perforated elastic body, and other than that, the above embodiment. Since the configuration is exactly the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and different points will be described.

  That is, the form of the natural material according to the first embodiment is columnar wood, and the columnar perforated elastic body has a cylindrical shape along with this, whereas the natural system according to the second embodiment is provided. The material is composed of four thin columnar timbers 16a, and these four columnar timbers 16a are subjected to pressure treatment at a time, and therefore the columnar perforated elastic body 17 has four perforated portions 17a in the axial direction. Are formed, and thin cylindrical timbers 16 a are loaded into the respective perforated portions 17 a via the cushioning material 18. In such a pressure treatment of a relatively thin natural material, a plurality of natural materials are pressed once by forming a plurality of hole portions 17a in the axial direction of the cylindrical perforated elastic body 17. It can be densified by compression.

  Next, a natural material densification method and a pressure densification apparatus according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 5 is a schematic cross-sectional view according to Embodiment 3 of the present invention and showing an arrow XX in FIG. However, the third embodiment of the present invention differs from the first embodiment in that there is a difference in the form of the natural material and the shape of the cylindrical perforated elastic body, and other than that, the above-described embodiment. Since the configuration is exactly the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and different points will be described.

  That is, the form of the natural material according to the first embodiment is columnar wood, and the columnar perforated elastic body has a cylindrical shape along with this, whereas the natural system according to the third embodiment is provided. The material is a quadrangular columnar wood 16b, and a cylindrical perforated elastic body 17 having a perforated portion 17a having a rectangular cross section is used as the material.

  In the case where there are a plurality of the quadrangular columnar timbers 16b, similarly to the second embodiment, a plurality of perforated portions having a rectangular cross section corresponding to the number may be provided. The perforated portion 17a having a rectangular cross section provided in the cylindrical perforated elastic body 17 is usually subjected to R (curved surface) processing in order to smooth the corner portion, so that there is a gap with the quadrangular columnar wood 16b. It is recommended that the quadrangular columnar wood 16b be wrapped and loaded with newspaper or the like serving as the cushioning material 18.

  Next, a wood / bamboo material densification method and a pressure densification device according to Embodiment 4 of the present invention will be described with reference to FIG. FIG. 6 is a schematic cross-sectional view according to Embodiment 4 of the present invention and showing an arrow XX in FIG. However, the difference between the fourth embodiment of the present invention and the first embodiment is that there is a difference in the form of the natural material and the shape of the cylindrical perforated elastic body, and other than that, the above-described embodiment. Since the configuration is exactly the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and different points will be described.

  That is, the form of the natural material according to the first embodiment is columnar wood, and the columnar perforated elastic body has a cylindrical shape along with this, whereas the natural material according to the fourth embodiment is The material is composed of two quadrangular columnar timbers 16c, and the cylindrical perforated elastic body 17 is provided with a perforated portion 17a having a rectangular cross section.

  However, the two quadrangular columnar timbers 16c are formed by combining the cylindrical perforated elastic body 17 and the rigid template 19 made of metal or ceramic so that a flat portion 16c 'is formed after pressure densification. Is loaded. In this case, it is preferable that two pieces of the quadrangular columnar timber 16c are disposed so as to face each other with the template 19 interposed therebetween. This is because if the square columnar wood 16c is one piece, the square plate-like wood 16c and the template 19 are deformed distorted.

  Next, a natural material densification method and a pressure densification apparatus according to Embodiment 5 of the present invention will be described with reference to FIG. FIG. 7 is a schematic cross-sectional view according to the fifth embodiment of the present invention and showing an arrow XX in FIG. However, the fifth embodiment of the present invention is different from the first embodiment in that there is a difference in the form of the natural material and the shape of the cylindrical perforated elastic body, and other than that, the above embodiment. Since the configuration is exactly the same as that of the first embodiment, the same components as those of the first embodiment are denoted by the same reference numerals, and different points will be described.

  That is, the form of the natural material according to the first embodiment is a columnar wood, and the columnar perforated elastic body has a cylindrical shape along with this, whereas the natural system according to the fifth embodiment is provided. The material is composed of four quadrangular columnar timbers 16d, and the cylindrical perforated elastic body 17 is provided with a perforated portion 17a having a rectangular cross section. Then, the template 19 is combined so that two orthogonal plane portions 16d 'are formed in each of the four quadrangular columnar timbers 16d by one press densification treatment.

  As in the first to fifth embodiments of the present invention, the perforated portion 17a provided in the cylindrical perforated elastic body 17 in accordance with the cross-sectional shape of the natural material 16-16d and the template 19 is provided in the perforated portion 17a. When the natural material 16 to 16d is loaded, the example in which the buffer material 18 is used in the surroundings has been described. However, as such a buffer material 18, paper such as newspaper or a particle size is relatively large (several 10 to 10). It is recommended to use ceramic particles such as alumina (several hundred μm).

  The cylindrical perforated elastic body 17 is a semi-consumable product. However, with such consideration, there is an excessive gap between the inner surface of the perforated portion 17a and the outer surface of the natural material 16-16d. However, unnecessary damage is avoided and long-term use is possible.

  As described above, the pressure densification treatment method for a natural material according to the present invention includes drying the natural material and then storing the natural material in a cylindrical high-pressure vessel with the axial direction aligned. It compresses and compresses two-dimensionally or axisymmetrically with fluid pressure from the direction perpendicular to the axial direction of the material, and then densifies, and then heat-treats to fix it, preventing shrinkage deformation and destroying the fiber structure The pressure densification treatment can be performed in a short time without any trouble.

  In the pressure densification device for natural materials according to the present invention, a pressurized space is formed by the inner surface of the cylindrical portion of the high-pressure vessel and the outer surface of the cylindrical membrane made of an elastic body attached to the inner surface of the cylindrical portion. In addition, a pressurized fluid introduction hole for introducing a pressurized fluid into the pressurized space is provided, and a cylindrical perforated elastic body is provided inside the cylindrical membrane for transmitting a pressurized compressive force by the pressurized fluid. The natural material is loaded into the perforated portion of the cylindrical perforated elastic body, and the natural material is removed from the direction perpendicular to the axial direction by the fluid pressure introduced into the pressurized space. Since it is configured to compress and compress through the cylindrical perforated elastic body in a dimensional or axisymmetric manner, a configuration capable of compressing and compressing without damaging the fiber structure of the natural material becomes possible. It was.

Next, examples and comparative examples of the natural material densification method and pressure densification apparatus according to the present invention will be described below with reference to FIGS.
<Example 1>
Naturally dried cedar grid material (dimensions: width 30 mm x length 100 mm x thickness 12 mm, density: 0.35 x 10 ³ kg / m ³ ) is used as a natural material 16b at a temperature of 105 ° C in the atmosphere. After drying for a period of time, the three sheets are overlapped and wrapped in newspaper so that the cross section becomes a substantially square (width 30 mm × thickness 36 mm), and a rectangular perforated portion made of latex rubber with a hardness of 70 degrees It was accommodated in the cylindrical perforated elastic body 17 shown in FIG. 5 in which 17a was formed, and loaded into the pressure densification apparatus 10 shown in FIG.

  Next, the pressurization pump was driven to pressurize the inside of the pressurization container to 150 MPa at a speed of about 50 MPa / min and then held for 1 minute. After depressurization, it was taken out from the pressure densification device 10, and it was confirmed that the natural material 16b was compressed in a direction in which the interval between the annual rings was reduced and the thickness was reduced to about 4 mm. This natural material 16b was further heat-treated in the atmosphere at a temperature of 170 ° C. for 24 hours.

The natural material 16b after the treatment was found to be 1.4 × 10 ³ kg / m ³ when the density of the natural material 16b after the treatment was measured without any significant change in size and shape. It was done. The natural material 16b after this treatment was treated in boiling water for 3 hours, but no large swelling phenomenon or the like was observed, and it was confirmed that the material was modified to a material with high density and less dimensional change.

<Example 2>
The natural dried bamboo slab with a diameter of about 90 mm was cut into a length of 200 mm and further cut in the axial direction to bundle them to form a natural material 16b having a width of about 15 mm and a thickness of about 10 mm. The density of these Buddhist bamboo materials was about 0.65 × 10 ³ kg / m ³ . After such a natural material 16b is dried in the atmosphere at a temperature of 90 ° C. for 24 hours, it is wrapped in newspaper and provided with a cylindrical perforated elasticity having a perforated portion 17a having a rectangular cross section as shown in FIG. It accommodated in the body 17 was mounted | worn with the press densification apparatus 10 of the structure shown in FIG. 2, and the pressurizing process for 1 minute was performed at 200 MPa.

It was confirmed that the natural material 16b after the treatment contracted mainly in the thickness direction, and the thickness was reduced to about half. This natural material was heat-treated at a temperature of 180 ° C. in the atmosphere for 12 hours. The natural material 16b after the treatment was slightly darkened in color and turned dark brown, but it was confirmed that the density was increased to a density of about 1.3 × 10 ³ kg / m ³ . In order to confirm the stability of the material, it was treated in boiling water for 3 hours, but no swelling phenomenon was observed, and it was confirmed that the material was modified to a very high density and good stability. It was done.

<Comparative Example 1>
The same cedar grain material as in Example 1 was subjected to a pressure treatment and a fixing treatment in the same manner as in Example 1 while being naturally dried. Although the density was densified to 0.93 × 10 ³ kg / m ³ , the densification could not be achieved to exceed the water density of 1.00 × 10 ³ kg / m ³ .

<Comparative example 2>
The same Buddhist bamboo material as in Example 2 was subjected to a pressure treatment under the same conditions as in Example 2 while being naturally dried, and evaluation was performed without performing the immobilization treatment. Although the density was 1.0 × 10 ³ kg / m ³ and densification was achieved to some extent, a slight swelling phenomenon was observed after a stability evaluation test for 3 hours in boiling water.

  As described above, according to the pressure densification processing method of a natural material according to the present invention, a cylindrical high pressure is applied after drying a natural material including an axial fiber structure in a tissue such as wood or bamboo. Store in a container with the axial direction aligned, pressurize and compress two-dimensionally or axisymmetrically with fluid pressure from the direction perpendicular to the axial direction of the natural material, and then heat-treat. Since it is fixed, it is possible to perform pressure densification treatment in a short time without preventing shrinkage deformation and destroying the fiber structure.

  In addition, according to the pressure densification treatment method of a natural material according to the present invention, the drying treatment is performed in the atmosphere at a temperature of 80 to 120 ° C., so that the densification can be made close to the true density of the natural material. In addition, the remaining bound water can contribute to facilitating deformation during pressurization.

  On the other hand, according to the pressure densification device for natural materials according to the present invention, the pressurized space is formed by the inner surface of the cylindrical portion of the high-pressure vessel and the outer surface of the cylindrical membrane made of an elastic body attached to the inner surface of the cylindrical portion. A pressurized fluid introduction hole is formed and a pressurized fluid introduction hole for introducing a pressurized fluid into the pressurized space is provided, and a cylindrical perforated elasticity is provided inside the cylindrical membrane to transmit a pressurized compressive force by the pressurized fluid. The natural material is loaded into the perforated portion of the cylindrical perforated elastic body, and the natural material is perpendicular to the axial direction by the fluid pressure introduced into the pressurized space. Since it is configured to compress and compress two-dimensionally or axisymmetrically through the cylindrical perforated elastic body, it is possible to configure so that it can be compressed without damaging the fiber structure of the natural material. It became.

  In the above-described embodiment, an example of wood / bamboo has been described. However, natural materials are not limited to wood / bamboo, and grass such as firewood or a combination of these may be used.

It is process drawing which shows the process of the densification processing method of the natural material which concerns on Embodiment 1 of this invention. It is a typical longitudinal cross-sectional view which shows the principal part of the pressure densification apparatus of the natural raw material which concerns on Embodiment 1 of this invention. FIG. 3 is a schematic cross-sectional view according to Embodiment 1 of the present invention and showing an arrow XX in FIG. 2. FIG. 5 is a schematic cross-sectional view according to Embodiment 2 of the present invention and showing an arrow XX in FIG. 2. FIG. 6 is a schematic cross-sectional view according to a third embodiment of the present invention and showing an arrow XX in FIG. 2. FIG. 7 is a schematic cross-sectional view according to Embodiment 4 of the present invention and showing an arrow XX in FIG. 2. FIG. 9 is a schematic cross-sectional view according to the fifth embodiment of the present invention and showing an arrow XX in FIG. 2. It is a schematic sectional drawing of the apparatus for the pressure processing of the timber by one Example which concerns on a prior art.

Explanation of symbols

1 to 5: Steps of the densification treatment method for natural materials Step 10: Pressure densification device, 11: Cylindrical portion 12a: Ring-shaped upper lid, 12b: Upper plug 13a: Ring-shaped lower lid, 13b: Lower lid 14: Pressurized space, 14a: Pressurized fluid introduction hole 15: Cylindrical membrane, 15a: Ear part 16, 16a: Columnar wood (natural material)
16b, 16c, 16d: Square pillar-shaped wood (natural material)
16c ', 16d': plane part 17: cylindrical perforated elastic body, 17a: perforated part 18: cushioning material, 19: template, 20: press frame

Claims (8)

  A natural material containing an axial fiber structure in a tissue such as wood or bamboo is dried and then stored in a cylindrical high-pressure container with the axial direction aligned, and the direction perpendicular to the axial direction of the natural material. A pressure densification treatment method for a natural material characterized in that it is compressed and compressed two-dimensionally or axisymmetrically with fluid pressure to be densified, and then subjected to heat treatment to be fixed.   The method for pressure densification treatment of a natural material according to claim 1, wherein the drying treatment is performed in an atmosphere at a temperature of 85 to 120 ° C.   The pressure densification treatment method for a natural material according to claim 1 or 2, wherein the fluid pressure is 30 to 400 MPa.   The pressure densification treatment method for a natural material according to any one of claims 1 to 3, wherein the heat treatment is performed at a temperature of 150 to 180 ° C.   The fluid pressure is compressed and compressed two-dimensionally or axisymmetrically from a direction perpendicular to the axial direction of the natural material through an elastic body that is attached to the inner surface of the cylindrical high-pressure vessel and contains the fluid pressure. The pressure densification treatment method for a natural material according to any one of claims 1 to 4, wherein the densification is performed.   6. The natural material is divided into a plurality of parts, and a rigid template is sandwiched between the divided materials to compress and compress the material to make it dense. The pressure densification processing method of the natural material as described in one item.   A pressurized space is formed by the inner surface of the cylindrical portion of the cylindrical high-pressure vessel and the outer surface of the cylindrical membrane made of an elastic body attached to the inner surface of the cylindrical portion, and pressurization for introducing a pressurized fluid into the pressurized space. A fluid introduction hole is provided, and a cylindrical perforated elastic body provided with a perforated portion in an axial direction for transmitting a pressurized compressive force by the pressurized fluid is housed inside the cylindrical membrane. A natural material made of wood or bamboo is loaded into the perforated portion of the cylindrical perforated elastic body, and the natural material is removed from the direction perpendicular to the axial direction by the fluid pressure introduced into the pressurized space. A pressure densification apparatus for natural materials, wherein the apparatus is configured to compress and compress two-dimensionally or axisymmetrically through the cylindrical perforated elastic body. The pressure densification device for natural materials according to claim 7, wherein the perforated portion of the cylindrical perforated elastic body is composed of a plurality of holes.

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