JP2008194948A - Pressurizing and densifying processor for natural raw material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressurizing and densifying processor capable of pressurizing and compressing a natural raw material consisting of a fiber structure oriented in the axial direction and another structure without giving a damage on the fiber structure, and fixing it by applying a heating processing to be able to efficiently perform densifying processing. <P>SOLUTION: The pressurizing and densifying processor stores the natural raw material 16 containing the fiber structure in the axial direction in the structure such as a wood material and a bamboo material in a high pressure container 10 consisting of a cylindrical part 11 with pressure resistance and an upper lid part 12 and a lower lid part 13 for sealing the top and the bottom of this cylindrical part 11, and pressurizes and compresses it from the vertical direction to the axial direction with a pressurizing fluid two-dimensionally or axially symmetrically and applies heating processing during densifying or after densifying to fix it. A heating gas introducing hole 21 for introducing a heating gas into the high pressure container 10 is provided in the upper lid part 12, and an exhausting hole 22 is provided in the lower lid part 13. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention compresses and compresses two-dimensionally or axisymmetrically a natural material including an axial fiber structure in a tissue such as wood or bamboo, from a direction perpendicular to the axial direction by applying fluid pressure. It is related with the pressure densification processing apparatus which heat-processes and fixes after densifying and / or densifying.

  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, natural kenaf fibers are combined with polylactic acid in the form of a matrix, and their use as natural composite materials is being studied. By correcting the lack of strength caused by the above, 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 treatment method, there has been proposed a method in which wood is softened in a high-pressure steam atmosphere and then compression-molded and fixed under high-pressure conditions (see, for example, Patent Document 1). According to this method, the whole wood is densified.

  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 is employed in which only the surface portion is heated and softened for pressurization, and a hot plate press or a hot press roll press is used (see Patent Document 2).

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. In the old 1910s British patent (see Patent Document 3), a 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. 6 is a schematic sectional view of an apparatus for pressure treatment of wood according to the prior art. According to this prior art, long wood elements 35a, 35b, 35c having a rectangular cross section mainly including a plate material are placed in the high-pressure vessel 31, and the wood elements 35a, 35b, 35c are further sealed through the diaphragm 34 and further airtight casing material. 33, 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 using members having guide surfaces 36a and 36b. Has also been proposed (see Patent Document 4).

  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 many cases, the target natural material is a plate material, which is mainly densified with a hot-press roll or a press on a flat plate, but these devices can only be applied to a plate material such as a flooring material. Has the disadvantages.

Furthermore, in the pressure densification process using isotropic pressure, the pressure of the fluid is compressed not only in the direction perpendicular to the fiber direction of the natural material but also in the axial direction, which is the fiber direction. 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. And has the disadvantage of being inefficient.
JP-A-3-231802 Japanese Patent Publication No. 4-3722 British Patent GB100.792 Japanese National Patent Publication No. 11-503377

  Accordingly, an object of the present invention is to compress and compress a natural material composed of a fiber structure oriented in the axial direction and other structures, such as wood and bamboo, without damaging the fiber structure and heating. An object of the present invention is to provide a pressure densification treatment apparatus that can be processed and fixed and efficiently densified.

  In order to achieve the above object, the means adopted by the pressure densification processing apparatus for natural materials 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. Stored in a high-pressure vessel comprising a cylindrical portion having pressure resistance and an upper lid portion and a lower lid portion for sealing the upper and lower sides of the cylindrical portion, and two-dimensionally or vertically by a pressurized fluid from a direction perpendicular to the axial direction. It is characterized by being a pressure densification treatment apparatus for fixing by applying a heat treatment after being densified while being compressed by axisymmetric pressure compression.

  At the same time, this pressure densification processing apparatus is characterized in that a heating gas introduction hole for introducing a heating gas into a high-pressure vessel is provided in the upper lid part, and an exhaust hole is provided in the lower lid part. To do. Here, the meaning of “vertical” or “axisymmetric” may be substantially vertical or substantially axially symmetric, and need not be completely vertical or axially symmetric.

  The natural material pressurization densification processing apparatus according to claim 2 of the present invention employs the natural material pressurization densification processing apparatus according to claim 1, wherein the natural material pressurization densification processing apparatus has an axial direction in the high-pressure vessel. A cylindrical perforated elastic body provided with a perforated portion is housed, and a natural material loaded in the perforated portion of the cylindrical perforated elastic body is densified.

  The natural material pressure densification processing apparatus according to claim 3 of the present invention is the natural material pressure densification processing apparatus according to claim 1 or 2, wherein the columnar perforated elasticity is used. A porous heat insulating material is interposed between the body and the natural material loaded in the perforated portion.

  The natural material pressurization densification processing apparatus according to claim 4 of the present invention employs the natural material pressurization densification processing apparatus according to any one of claims 1 to 3. In the above, a heat insulating material is attached to a heating gas pipe connected to the heating gas introduction hole.

  The natural material pressure densification processing apparatus according to claim 5 of the present invention employs the natural material pressure densification processing apparatus according to any one of claims 1 to 4. In addition, a buffer material having electrical insulation is disposed on the outer periphery of the natural material, and a heating element made of conductive powder for generating Joule heat is disposed on the outer periphery of the buffer material. A heat insulating material having electrical insulation is disposed on the outer periphery of the body.

  The natural material pressure densification processing apparatus according to claim 6 of the present invention employs the natural material pressure densification processing apparatus according to any one of claims 1 to 5. The temperature detecting means is disposed on the outer periphery of the natural material, and the electric power supplied to the heating element is controlled so that the temperature becomes a predetermined temperature while detecting the temperature of the natural material. It is characterized by.

  According to the pressure densification processing apparatus for a natural material according to claim 1 of the present invention, a natural material including an axial fiber structure in a tissue such as wood or bamboo is used as a cylindrical portion having pressure resistance and the cylinder. It is housed in a high-pressure vessel composed of an upper lid and a lower lid for sealing the upper and lower parts, and is compressed by two-dimensional or axisymmetric pressure compression with a pressurized fluid from a direction perpendicular to the axial direction. A pressure densification processing apparatus for fixing after heating and / or densification, wherein a heating gas introduction hole for introducing a heating gas into the high-pressure vessel is provided in the upper lid portion Since the lower lid is provided with an exhaust hole, the pressure densification treatment and the fixation treatment can be performed simultaneously and / or continuously without preventing shrinkage deformation and destroying the fiber structure. A pressure densification treatment apparatus for natural materials can be provided.

  Moreover, according to the pressure densification processing apparatus for natural materials according to claim 2 of the present invention, a cylindrical perforated elastic body provided with a perforated portion in the axial direction is accommodated in the high-pressure vessel, Since the natural material loaded in the perforated portion of the cylindrical perforated elastic body is densified, it is compressed and compressed two-dimensionally or axisymmetrically from a direction perpendicular to the axial direction to the natural material. Can be realized reliably.

  Furthermore, according to the pressure densification processing apparatus for a natural material according to claim 3 of the present invention, a porous material is provided between the columnar perforated elastic body and the natural material loaded in the perforated portion. Since the heat insulating material is interposed, the natural material can be uniformly heated by forming a uniform flow without hindering the flow of the heated gas in the high-pressure vessel.

  Furthermore, according to the pressure densification processing apparatus for natural materials according to claim 4 of the present invention, since a heat insulating material is attached to the piping for heating gas connected to the heating gas introduction hole, It can supply heated gas at a constant temperature that is not affected by fluctuations in environmental temperature.

  According to the pressure densification processing apparatus for a natural material according to claim 5 of the present invention, a buffer material having electrical insulation is disposed on the outer periphery of the natural material, and further, a joule is disposed on the outer periphery of the buffer material. A heating element made of conductive powder for generating heat is disposed, and a heat insulating material having electrical insulation is disposed on the outer periphery of the heating element.

  Therefore, the heating element can be used many times for pressure densification treatment of natural materials having different shapes and dimensions, and has high followability to deformation during the pressure treatment. In addition, after the heating / pressurizing treatment, even if the resin component solidified from the natural material is solidified, it can be easily regenerated into a powder state and reused, which is preferable from the viewpoint of economy. Moreover, since an electrically insulating cushioning material is disposed on the outer periphery of the heating element, there is no fear of leakage or electric shock.

  Moreover, according to the pressure densification processing apparatus for natural material according to claim 6 of the present invention, a temperature detecting means is disposed on the outer periphery of the natural material, while detecting the temperature of the natural material. Since the input power to the heating element is controlled so that the temperature becomes a predetermined temperature, the heating temperature of the natural material can be accurately maintained at the predetermined temperature.

  A natural material densification apparatus according to Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic longitudinal sectional view showing a main part of a pressure densification processing apparatus for natural materials according to Embodiment 1 of the present invention, and FIG. 2 shows a case where the natural material of FIG. 3 is a schematic cross-sectional view showing the arrow XX, FIG. 3 is a schematic cross-sectional view showing the arrow XX when the natural material of FIG. 1 is a plurality of small-diameter cylindrical wood, and FIG. It is typical sectional drawing which shows arrow XX in case a natural type material is square pillar-shaped wood.

  In FIG. 1, a pressure densification treatment apparatus for a natural material including an axial fiber structure in a tissue according to Embodiment 1 of the present invention includes a cylindrical portion 11 having pressure resistance and an upper end of the cylindrical portion 11. The high-pressure vessel 10 includes an upper lid portion 12 for sealing the lower end portion 13 and a lower lid portion 13 for sealing the lower end of the cylindrical portion 11. Here, the upper lid portion 12 is composed of a ring-shaped upper lid 12a and an upper plug 12b, and the lower lid portion 13 is composed of a ring-shaped lower lid 13a and a lower plug 13b. Reference numeral 20 denotes a press frame that presses and supports the upper lid 12 from above.

  And the pressure densification processing apparatus which concerns on Embodiment 1 of this invention is from the 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 10. A cylindrical membrane 15 is mounted, and a hole having a circular cross section is provided inside the cylindrical membrane 15 in order to transmit a pressurized compression force by a pressurized fluid to the columnar wood 16 which is a natural material. A cylindrical perforated elastic body 17 having the portion 17a provided in the axial direction is accommodated.

  At the same time, the natural material 16 can be loaded into the perforated portion 17 a of the cylindrical perforated elastic body 17 via the porous heat insulating material 18. 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.

  Further, the ring-shaped upper lid 12 a constituting the upper lid portion 12 has a heated gas introduction hole 21 for supplying a heated gas to the inside of the high-pressure vessel 10, and the ring-shaped lower lid 13 a constituting the lower lid portion 13 includes An exhaust hole 22 is provided for discharging the heated gas supplied from the heated gas introduction hole 21 and the gas component generated from the natural material 16 from the inside of the high-pressure vessel.

  That is, in the pressure densification processing apparatus, the pressure space 14 formed by the outer surface of the cylindrical membrane 15 and the ear portions 15a at both ends thereof and the inner surface 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.

  At the same time, the cylindrical wood 16 can be heated by the heated gas supplied from the heated gas introduction hole 21, and the heated gas and the gas component generated from the cylindrical wood 16 can be discharged from the exhaust hole 22. is there.

  The function of the pressure densification processing apparatus according to the first embodiment of the present invention having such a configuration will be described below along the pressure densification processing step of the natural material 16. Generally, natural materials such as wood and bamboo are cut into a length that can be stored in the high-pressure vessel 10 of the pressure densification apparatus and then dried using a drying furnace in the atmosphere. used. 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.

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. ^Although it is densified to a density close to ³ kg / m ³ , the wood / bamboo material densified by this pressure compression will be restored when exposed to boiling water. Alternatively, the immobilization process is performed by heating after the pressurizing process.

  The pressure densification apparatus according to the present invention is an apparatus for compressing and compressing a natural material two-dimensionally or axisymmetrically in a direction perpendicular to the axial direction under heating, for example, at a temperature of 150. A natural material preheated at ℃ is pressurized in this device to perform densification treatment, and then heated steam at a temperature of 170 ℃ is introduced into the device for continuous immobilization treatment, or a temperature of 170 ℃ This makes it possible to simultaneously perform a densification process by pressure compression and an immobilization process for preventing deformation under heating.

  In the case of the pressure densification treatment by the latter, it is preferable to perform pressure compression under heating at a temperature of 150 to 180 ° C. Therefore, it is preferable to preheat to a certain temperature before loading the natural material to be processed in the apparatus in order to shorten the pressure densification processing time, for example, at a temperature of 100 to 150 ° C. It is recommended to preheat to the range.

  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.

  As shown in FIG. 1, the natural material 16 preheated in this way has an axial fiber structure aligned in the high-pressure vessel 10 of the pressure densification apparatus according to Embodiment 1 of the present invention. The pressurized fluid is supplied to the pressurized space 14 formed by the cylindrical membrane 15 and the inner surface of the cylindrical container 11 while being supplied in a state and supplying the heated gas from the heated gas introduction hole 21, and inside thereof It receives a compressive force in the centripetal direction in an axisymmetric manner through the arranged cylindrical perforated elastic body 17 and the porous heat insulating material 18 made of ceramic powder or the like. It should be noted that the meaning of “alignment” in this case may be generally aligned, and is not required to be completely aligned.

  The cylindrical wood 16 contracts in the centripetal direction by such pressure and compression force, and this contraction deformation is fixed by heating with the heated gas, so the pressure applied by the pressurized fluid is released and the heated gas is exhausted. Even if it is discharged from the hole 22 and the temperature is returned to room temperature, the compressed and deformed state is maintained except for elastic recovery.

  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, it is preferable to dispose the porous heat insulating material 18 on the outer periphery of the cylindrical wood 16 in order to prevent the cylindrical porous elastic body 17 from being easily damaged.

  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 capable of being adapted to 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, and various types are used depending on the shape of the natural material 16.

  The most typical example is used for the treatment of cylindrical wood as described above. As shown in FIG. 2, the cross-sectional shape of the perforated portion 17a is circular, and the diameter is the diameter of the cylindrical wood 16. As a slightly larger size, the porous heat insulating material 18 made of the aforementioned ceramic powder or the like is disposed in the gap.

  In the case where the natural material is, for example, a small-diameter columnar wood 16a, as shown in FIG. 3, the columnar perforated elastic body 17 is provided with a plurality of perforated portions 17a larger than the cross section, and Similarly, the porous heat insulating material 18 which consists of the ceramic powder mentioned above is arrange | positioned in those clearance gaps. The porous heat insulating material 18 also serves as a cushioning material for preventing damage to the cylindrical perforated elastic body 17.

  When the natural material is a quadrangular columnar wood 16a, as shown in FIG. 4, the cylindrical perforated elastic body 17 is provided with a perforated portion 17a having a rectangular cross section larger than the quadrangular column cross section. The porous heat insulating material 18 made of the aforementioned ceramic powder or the like is disposed in the gap. It is preferable that the corner portion of the effective portion 17a is usually R-processed (chamfered) so as to be smoothly pressurized and compressed.

  The heated gas or heated steam introduced from the heated gas introduction hole 21 heats the natural material 16, 16 a, 16 b when flowing in the porous space of the porous heat insulating material 18 thus arranged. And discharged from the exhaust hole 22 to the outside of the system. If it has already been preheated, the heating time in this apparatus is sufficient for several minutes.

  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 of the natural material. is there. 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.

  Furthermore, the pressure densification treatment apparatus according to the present invention is characterized in that it can perform a heat densification treatment in which a heat treatment is performed simultaneously or continuously with a pressure densification treatment of a natural material. A heated gas, more preferably heated steam is supplied from outside the system into the pressurized container so that the natural material can be heated. In this case, it is known that when heated steam is used, the immobilization process can be performed efficiently, that is, in a shorter time than a heated gas at the same temperature. Sufficient immobilization processing is realized.

  In particular, when heated for a long time, blackening occurs due to carbon generation or oxidation phenomenon due to thermal decomposition of a part of the lignin in the natural material. The densification processing apparatus is suitable for realizing this purpose. The heated water vapor is supplied from the heated gas introduction hole 21 and passes through the porous portion of the porous heat insulating material 18 made of ceramic powder or the like to heat the natural material 16. Moisture and gas components generated from the gas pass through the porous filler 23 disposed below (and above) the natural material 16 and are discharged out of the system through the exhaust holes 22 provided in the lower lid. The

  Note that the temperature of the heating gas that is a heating heat source is very important, and in order to eliminate the influence of temperature fluctuations due to the ambient environmental temperature, a heat insulating material 21a should be attached to the piping of the heating gas introduction hole 21. Is recommended. Heating with electric power is also effective as a heating heat source. However, heating the entire high-pressure vessel 10 requires a long time until the entire apparatus is heated to a predetermined temperature in terms of energy efficiency, and the entire vessel. It is not realistic because of safety problems caused by the high temperature. The present invention proposes a pressure densification treatment apparatus that avoids such harmful effects due to the use of electric power and simultaneously uses pressure densification and heating by electric power, as shown in the second embodiment below. is there.

  Next, a natural material densification apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 5 is a schematic longitudinal sectional view showing a main part of a pressure densification processing apparatus for natural materials according to Embodiment 2 of the present invention. However, the second embodiment of the present invention differs from the first embodiment in that there is a difference in the heating method of the natural material, and the rest of the configuration is exactly the same as in the first embodiment. The same reference numerals are given to the same components as those in the first embodiment, and the different points will be described.

  That is, while the heating method of the natural material according to the first embodiment is a heating method using a heated gas, the heating method according to the second embodiment is a heat generation made of conductive powder around the natural material. This is a system in which a body is disposed and this heating element generates Joule heat.

  To describe the configuration of the heat generation method in more detail, an electric insulating material 25 is disposed on the outer periphery of the natural material 16, and a metal powder is placed in a space between the electric insulating material 25 and the porous heat insulating material 18. A heating element 24 made of conductive powder such as carbon powder is disposed, and a disk-like electrode member 24a is disposed at the upper end of the heating element 24 to provide electrical insulation from the upper lid 12. It is connected to a heating power source (not shown) via the introduced power supply lead wire 26.

  And the lower end of the said heat generating body 24 which consists of electroconductive powder is directly couple | bonded with the lower plug 13b, and it has the structure where the said lower plug 13b plays the role of the other electrode member for electricity supply. The heating element 24 configured as described above is controlled in heating power so that the temperature detected by the temperature detection means disposed on the outer periphery of the natural material 16 becomes a predetermined temperature.

  As the temperature detecting means, a thermocouple, a resistance temperature detector, or the like can be used. The setting method and the temperature control method when the thermocouple 27 is used will be described in more detail below. First, the lower lid portion 13 constituting the high-pressure vessel 10 and a set of columnar perforated elastic bodies 17 and the like mounted thereon are lowered downward by removing the lower lid portion 13 from the lower end of the cylindrical portion 11. The natural material 16 is stored in a predetermined position. At that time, with the lower lid portion 13 lowered, a block-like porous filler 23 was placed on the lower lid portion 13, and the natural material 16 was stored on the porous filler 23. Thereafter, a sheet-like electrical insulating material 25 having a thermocouple 27 attached to the inner peripheral side is wound around and fixed to the outer periphery of the natural material 16.

  Then, the porous heat insulating material 18 having a cylindrical shape and the columnar perforated elastic body 17 are dropped onto the outer peripheral side of the natural material 16 from above. Thereafter, the heating element 24 made of conductive powder is filled into an annular gap formed between the electrical insulating material 25 and the porous heat insulating material 18. Next, the lower lid portion 13 and the above-described set mounted thereon are raised and attached to the lower end of the cylindrical portion 11. Thereafter, the upper plug 12b is opened, the porous filler 23 is inserted from the upper opening, the electrode member 24a is placed thereon, and the porous filler 23 is also placed in the upper space. After completion of the pressure densification treatment, the lower lid portion 13 is lowered downward in the same manner as in the setting method described above, and the natural material 16 that has been treated is recovered.

  The thermoelectromotive force signal generated by the thermocouple 27 set in this way is taken out of the system by the compensating lead wire 27a, appropriately amplified, and applied to the gate circuit of the thyristor for supplying heating power through the PID control circuit. Thus, the heating power supplied to the heating element 24 is controlled so as to follow a predetermined time-temperature program.

  Also in Embodiment 2 of the present invention, it is possible to supply heating gas and heating steam from the heating gas introduction hole 21 in parallel. By using heating gas and electric heating in combination, more accurate temperature control can be achieved by adjusting the input power to the heating element 24. Even when heating with a heating gas is used in this way, it is preferable to dispose the temperature detecting means on the outer periphery of the natural material 16 for temperature control and control the heating power based on the detected temperature. .

  In the pressure densification processing apparatus according to Embodiment 2 of the present invention, conductive powder, that is, metal powder, carbon powder, or the like is used as the heating element 24. It can be used any number of times for pressure densification treatment of natural materials having different shapes and dimensions, and has high followability to deformation during pressure treatment. In addition, after the heating and pressurizing treatment, these powder materials can be easily regenerated into a powder state and reused even when solidified by the resin component squeezed out from the natural material 16. This is very preferable from the viewpoint of economy.

  As described above, according to the pressure densification treatment apparatus for natural materials according to the present invention, as a carbon neutral material that is less affected by global warming due to the release of carbon dioxide, it is expected to be effectively used in recent years. It is possible to modify low-density coniferous forest materials such as cedar and cypress and natural materials such as bamboo to materials having high density and high strength. In particular, it becomes possible to perform the immobilization process after densification, which is required in normal pressure densification treatment, simultaneously or continuously with pressure densification, and the processing time of the entire pressure densification treatment process. It has the effect that productivity is improved by shortening.

  Furthermore, from the viewpoint of specific strength, it can be used as a structural material that surpasses some steel and aluminum materials, and is expected to be developed as an industrial product. In particular, it is ideal for manufacturing bars made of natural materials, and will provide material technologies that will contribute to environmental conservation in the future, such as enabling use as parts and furniture for home appliances and some building materials. It is a great place to contribute as a thing.

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

It is a typical longitudinal cross-sectional view which shows the principal part of the pressure densification processing apparatus of the natural type material which concerns on Embodiment 1 of this invention. It is typical sectional drawing which shows arrow XX in case the natural type material of FIG. 1 is columnar timber. It is a typical sectional view showing arrow XX when the natural system material of Drawing 1 is a plurality of small diameter columnar timber. It is typical sectional drawing which shows arrow XX in case the natural type material of FIG. 1 is a square pillar-shaped wood. It is a typical longitudinal cross-sectional view which shows the principal part of the pressure densification processing apparatus of the natural type material which concerns on Embodiment 2 of this invention. It is a schematic sectional drawing of the apparatus for pressure processing of the timber based on a prior art.

Explanation of symbols

10: High pressure vessel, 11: Cylindrical portion 12: Upper lid portion, 12a: Ring-shaped upper lid, 12b: Upper plug 13: Lower lid portion, 13a: Ring-shaped lower lid, 13b: Lower plug 14: Pressurized space, 14a: Additional Pressure fluid introduction hole 15: Cylindrical membrane, 15a: Ear portion 16, 16a: Columnar wood (natural material)
16b: Square columnar wood (natural material)
17: Cylindrical perforated elastic body, 17a: Perforated part 18: Porous heat insulating material, 20: Press frame 21: Heated gas introduction hole, 21a: Heat insulating material 22: Exhaust hole, 23: Porous filler 24: Heat generation Body, 24a: electrode member 25: electrical insulating material (buffer material), 26: feeding lead wire 27: thermocouple (temperature detecting means), 27a: compensating lead wire

Claims (6)

  Natural materials such as wood and bamboo that contain an axial fiber structure are housed in a high-pressure vessel that consists of a pressure-resistant cylindrical part and an upper and lower lid part that seals the top and bottom of the cylindrical part. And pressurizing and compressing in a two-dimensional or axisymmetric manner with a pressurized fluid from a direction perpendicular to the axial direction and / or densifying, and then applying heat treatment to fix the pressed dense A natural material characterized in that a heating gas introduction hole for introducing a heating gas into a high-pressure vessel is provided in the upper lid part, and an exhaust hole is provided in the lower lid part. Pressure densification processing equipment.   A cylindrical perforated elastic body provided with a perforated portion in the axial direction is accommodated in the high-pressure vessel, and the natural material loaded in the perforated portion of the cylindrical perforated elastic body is densified. The pressure densification processing apparatus for natural materials according to claim 1.   The natural material according to claim 1 or 2, wherein a porous heat insulating material is interposed between the columnar perforated elastic body and the natural material loaded in the perforated portion. Pressure densification processing equipment.   The pressure densification of the natural material according to any one of claims 1 to 3, wherein a heat insulating material is attached to a heated gas pipe connected to the heated gas introduction hole. Processing equipment.   A buffer material having electrical insulation is disposed on the outer periphery of the natural material, and a heating element made of conductive powder for causing Joule heat generation is disposed on the outer periphery of the buffer material. The heat densification processing apparatus for natural materials according to any one of claims 1 to 4, wherein a heat insulating material having electrical insulation is disposed on an outer periphery. A temperature detection means is disposed on the outer periphery of the natural material, and the electric power supplied to the heating element is controlled so that the temperature becomes a predetermined temperature while detecting the temperature of the natural material. The pressure densification processing apparatus for natural materials according to any one of claims 1 to 5.

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