JP4502848B2 - Plant-based hot-press molding material having fibers and method for producing the same - Google Patents

Description

  The present invention relates to a plant-based molding material containing fibers, which has an arbitrary three-dimensional shape, which is an alternative to plastics, and a method for producing the same. More specifically, the present invention relates to a predetermined temperature on bamboo, wood, etc. By applying pressure, a method for producing a new plant-based molding material that enables production of a molded article containing fibers, which exhibits fluidity while retaining the fibers, and has an arbitrary three-dimensional shape. And a new type of plant-based molding material that can cope with resource and environmental problems.

  Plastics are relatively easy to manufacture complex shaped products, and currently occupy an important position as a material and are used in a wide range of fields. Most of the raw material is oil, which is a reserve resource, but considering the situation where there is concern about the future depletion of oil, it is necessary to develop a new molding material to replace it. Against this background, in recent years, research has been progressing toward the development of molding materials that use plant resources that can be produced sustainably. For example, various plants such as corn, kenaf, and wood are used as raw materials. Attempts have been made to develop such materials (see Non-Patent Documents 1 to 3, for example).

  Conventionally used plant materials include wood and bamboo. These wood and bamboo are materials that are generally used by processing methods such as “cut” and “shave”. In order to produce the desired shape, in some cases, wood and bamboo are finely glued to some extent. However, in the case of such a processing method, a complicated three-dimensional shape cannot be provided, and the use of the material is limited.

  Therefore, in order to produce a product with an arbitrary three-dimensional shape, a large amount of resin is mixed into finely pulverized wood or bamboo to make the raw material flowable, and this is poured into a mold for cooling and solidification. Things have been done. In addition, a method has been attempted in which fluidity is improved by subjecting finely pulverized wood or bamboo material to steam treatment or explosion treatment without using a resin, and molding using only these materials (for example, Non-Patent Document 4). 5).

  In the case of a conventional molding method in which a resin is mixed, in order to produce a material having fluidity and pouring the raw material into every corner of the mold to give a complicated three-dimensional shape, the resin is used in a weight ratio. It is necessary to mix about 50%. However, the conventional molding technology that incorporates resin is based on mixing finely pulverized wood and bamboo with a large amount of resin and solidifying it, and has the advantage of biodegradability inherent to wood and bamboo. Is detrimental. In addition, since it is difficult to separate a mixed material of wood, bamboo, and resin into wood, bamboo, and resin, there is a problem in recycling.

  At present, there is a concern about the depletion of reserve resources. Therefore, it is a social requirement to replace the resin made from petroleum, which is a reserve resource, with a reproducible alternative. On the other hand, a method has been attempted in which a finely pulverized wood or bamboo material is subjected to steam treatment or explosion treatment to improve fluidity without using a resin, and molding is performed using only these materials. However, these pretreatment steps are complicated, and improvement is demanded from the viewpoint of productivity.

  In any of the above cases, it is necessary to pulverize the raw material wood or bamboo. However, in order to pulverize the wood or bamboo, a large amount of energy is required, so that improvement is required from the viewpoint of manufacturing cost. . Moreover, by pulverizing the raw material, the fiber of the raw material is divided, and the advantage obtained by the raw material containing the fiber is lost.

  So far, the present inventors have aimed to apply a molding method such as extrusion molding, injection molding, etc., by making bamboo basket into powder and controlling its temperature and moisture content to develop fluidity. Although powdering can be expected to improve fluidity and homogenize the material, there is a problem that the high-strength fiber structure inherent to bamboo is destroyed. In addition, bamboo is not fully utilized despite its rapid growth and high productivity. In Japan, bamboo forests and satoyama that have been left unused are eroded by the so-called abandoned bamboo forest problem, and the development of new ways to use bamboo has been strongly demanded.

Kenichi Kudo, Applied Glycoscience, 4-41, (1994), 457-464 Kenji Onishi, Kazuaki Umeoka, Hideyuki Ando, Matsushita Electric Engineering Technical Report, 80, (2003), 58-63 Yuji Imanishi, Yuzo Furuta, Yoshihiro Obata, Kozo Kanayama, Abstracts of the 51st Annual Meeting of the Wood Society of Japan, (2001), 251 Hisao Kishi, Nakayama Nakayama: Abstracts of the 52nd Annual Meeting of the Wood Society of Japan, Gifu, 2002, p246 Tetsuko Takahashi, Ikuo Takasu, Yoji Kikata: Abstracts of the 54th Annual Meeting of the Wood Society of Japan, 2002, p275

  Under such circumstances, in view of the prior art, the present inventors use bamboo or wood as a raw material, do not use resin or the like, do not powder, and use bamboo or wood. As a result of intensive research aimed at developing a new molding technology that can produce complex shaped molded bodies by molding means that make use of the fiber structure of the fiber, by utilizing the self-adhesiveness of fiber cells and parenchyma cells The inventors have found that the intended purpose can be achieved, and have further researched to complete the present invention. The present invention uses a plant material such as wood or bamboo which is a reproducible resource as a raw material, and a molded product having a complicated three-dimensional shape while retaining the raw material fibers without going through a pulverization process. And it aims at providing the method of manufacturing this molded object. Another object of the present invention is to provide a method for producing a plant-based molded article having fibers with an arbitrary three-dimensional shape, which is an alternative to plastics, and a product thereof.

The present invention for solving the above-described problems comprises the following technical means.
(1) as a starting material the plant material with fibers, without passing through the powdered step by grinding, solidified using a self-adhesive material fiber, by molding, having fibers arbitrary three-dimensional shape is imparted A plant-based molded article,
In the plant material with fibers, the raw fibers in a state of holding the, the material was expressed while flowability was holding the fibers by the application of heat and pressure, any thermally molding by mold plant-base molded article having a fiber characterized in that the three-dimensional shape is imparted.
(2) The plant-type molded object which has the fiber as described in said (1) whose plant-type material which has a fiber is bamboo, wood, and / or vegetation.
(3) plant based molded body having an arbitrary three-dimensional shape is imparted fiber, an intermediate material or molded products, plant-based molded article having a fiber according to (1).
(4) Without pulverizing the plant-based material having fibers, the plant-based material is made to exhibit fluidity while holding the fibers by applying heat and pressure, and the material is poured into a mold. A method for producing a plant-based molded article having fibers, characterized in that a molded article containing fibers imparted with an arbitrary three-dimensional shape is obtained by pressing and self-adhesiveness of raw material fibers.
(5) The manufacturing method of the plant type molded object which has a fiber as described in said (4) which carries out injection molding of the plant type material which has the said fiber, and obtains a molded object.
(6) The manufacturing method of the plant-type molded object which has a fiber as described in said (4) which extrudes the plant-type material which has the said fiber, and obtains a molded object.

Next, the present invention will be described in more detail.
This invention solidifies and shape | molds the raw material fiber without powdering, The plant-type thermo-pressure-molded body which has a fiber, and the plant-type material which has a fiber, It is made to hold | maintain a fiber by applying heat and pressure It is characterized by a method for producing the molded body, which exhibits fluidity, is poured into a mold and pressed to produce a molded body having a three-dimensional shape containing fibers.

  In the present invention, the plant-based material having the raw material fibers may be an appropriate one, and preferably, for example, bamboo, wood, and vegetation are exemplified, but the invention is not limited thereto, and the same effect as these. Any other material can be used in the same manner. Heat and pressure are applied to these raw materials for a certain period of time to develop fluidity, introduced into a mold, and hot pressed to produce a molded body. In this case, for example, a piston cylinder mold is preferably used as the mold, but the mold is not particularly limited as long as it can be molded into a complicated shape, for example. The pressing is preferably performed by, for example, a press, but the compression may be any method and means that can spread the material to every corner of the mold, and the processing time is particularly Not limited.

  In the production method of the present invention, the fluidity can be expressed without losing the fibers of the raw material by applying a predetermined temperature and pressure without powdering the raw material. After that, by pressing the material into the mold, the material as the raw material is distributed to every corner of the mold, and a material containing fibers having a complicated three-dimensional shape can be produced. In the present invention, the raw material is not particularly limited to bamboo, and the method of the present invention can be applied to general plants having similar properties containing fibers.

  By replacing the plant-based molding material according to the present invention with a material made of metal or plastic as a raw material, it is possible to reduce the environmental load during product disposal. At the same time, since no resin is mixed in the plant-based molding material, it is possible to avoid the problem of separating the material and the resin during recycling. Furthermore, since the plant-based molding material of the present invention uses only a material that is a reproducible resource as a raw material, it can be expected to be a fundamental solution to the resource problem.

  By using the plant-based molding material obtained by the present invention as an alternative to conventional materials manufactured using metal or plastic as a raw material, for example, as an alternative to the housing of electrical appliances, resource / environmental problems related to disposal and recycling of materials Can be a solution to this.

  In the present invention, a predetermined temperature and pressure are applied to a plant-based material having fibers to develop fluidity while retaining the fibers, for example, by pressing into a mold and then cooling and solidifying. According to the present invention, (1) using only plant materials such as wood and bamboo, as a raw material, a powdering step is performed. In addition, it is possible to produce and provide a fiber-containing molding material having a complicated three-dimensional shape, and (2) by using the method for producing a plant-based molding material according to the present invention, A special effect is obtained in that it is possible to obtain a substitute for a material made of plastic in a form corresponding to environmental and resource problems.

  Next, the present invention will be specifically described based on test examples and examples, but the present invention is not limited to the following test examples and examples.

Test Example (1) Bamboo Structure In this test example, a molded body having a complex shape was produced using bamboo as a raw material, and a molding method using the bamboo fiber structure was tested. Bamboo bamboo is mainly composed of parenchyma cells and fiber cells. In FIG. 1, the SEM image which looked at the cross section of the bamboo basket from diagonally upward is shown. In the figure, P indicates parenchymal cells and F indicates a bundle of fiber cells (vascular sheath). Soft cells are strips or spheres with a length of about 100 μm, whereas fiber cells are elongated fibrous cells with a width of several tens of μm and a length of about 2 to 3 mm. Is different. Looking at the bamboo basket as a whole, parenchyma cells account for about 50% and fiber cells account for about 40% (Liese, W., Wood Science and Technology, 21-3, 194 (1987)), but the distribution is uniform. Instead, as shown in FIG. 2, the ratio of fiber cells is large on the epidermis side, and the ratio of parenchymal cells is large on the lumen side. Therefore, the properties of bamboo baskets are greatly different between the epidermis side and the lumen side.

(2) Sample A disc-shaped bamboo piece was cut out from the buttocks of a third-year Phylostachys pubescens using a circle cutter. FIG. 3 shows the obtained bamboo pieces. Also, this bamboo piece is split in the fiber direction and divided into an outer skin side half and a lumen side half to obtain a bamboo piece from the outer skin side rich in fiber cells and a bamboo piece from the lumen side rich in soft cells. It was. In the following tests, these bamboo pieces were air-dried (water content 10%) and used as samples.

(3) Injection Molding FIG. 4 shows an outline of a molding method by injection molding. The figure shows the steps of fluidizing, injection, cooling, and ejection. Into a mold heated to 200 ° C, a disc-shaped bamboo piece (Bamboo particle) is placed with the outer side facing up, pressurized with a piston (Piston), and flows out from a capillary (Capillary, diameter 2 mm, length 10 mm) The material was filled into a gear-shaped cavity (Cavity). The inner diameter of the cylinder (Cylinder) was 30 mm, the load applied to the piston was 100 kN, and the average surface pressure applied to the piston at this time was 142 MPa.

(4) Extrusion Molding Bamboo pieces from the outer skin side with many fiber cells and bamboo pieces from the lumen side with many soft cells were allowed to flow out of the capillaries in the same manner as the injection molding in (3) above. The set temperature was 200 ° C., and the load applied to the piston was 100 kN (average surface pressure 142 MPa). However, the material discharged from the capillary did not fill the cavity, and an effluent (extruded product) was obtained.

(5) Results FIG. 5 shows the obtained molded body. The material was filled to every corner of the mold, and a dense molded body with a smooth surface was obtained. FIG. 6 shows a micrograph of the inside of the molded body observed by cutting the molded body. A structure derived from bamboo fiber cells was observed in the molded body.

  FIG. 7 shows an outflow (extruded product) from a capillary obtained by flowing a bamboo piece from the outer skin side with a lot of fiber cells and a bamboo piece from the lumen side with a lot of soft cells. Although the effluent (left) obtained from bamboo pieces with many fiber cells was fragmented, the effluent (right) obtained from bamboo pieces with many parenchyma cells was a rod-shaped shaped body. It is thought that there is a great difference in self-adhesion between fiber cells and parenchyma cells. From this, by using bamboo pieces from the outer skin side with a lot of fiber cells and bamboo pieces from the lumen side with a lot of parenchymal cells alone or arbitrarily mixed, their self-adhesiveness is arbitrarily adjusted It turns out that the body can be made.

  A material with a diameter of 29 mm and a thickness of about 10 to 15 mm was cut out from a cedar (Cryptomeria japonica) sapwood and a butterfly of a 3-year-old Mosouchiku (Phyllostachys pubescens) with a circle cutter to an air-dried state (water content about 10%). It was subjected to molding without powdering. For molding, an injection molding method using a piston / cylinder mold having a capillary and a cavity was used. The material was put into a cylinder heated to 200 ° C., pressurized with a piston, and allowed to flow out of a capillary (diameter 2 mm, length 10 mm), and the gear-shaped cavity was filled with the material. The inner diameter of the cylinder was 30 mm, the load applied to the piston was 100 kN, and the average surface pressure applied to the piston at this time was 142 MPa.

  After filling the material with the cavity, the mold was cooled and the molded body was taken out. The obtained molded body had a smooth surface and was plastic-like. In addition, a fiber structure derived from the cedar and mosouchi as raw materials was confirmed inside the molded body observed by cutting the molded body. Since this fiber structure is considered to favorably affect the properties of the molded body, it has been shown that the present molding method can be expected to have a superior advantage over the powdered molding method.

  A material with a diameter of 29 mm and a thickness of about 10 to 15 mm was cut out from a cedar (Cryptomeria japonica) sapwood and a butterfly of a 3-year-old Mosouchiku (Phyllostachys pubescens) with a circle cutter to an air-dried state (water content about 10%). It was subjected to molding without powdering. For the molding, an extrusion molding method using a piston / cylinder mold having a capillary was used. The material was put into a cylinder heated to 200 ° C., pressurized with a piston, and allowed to flow out from a capillary (diameter 2 mm, length 10 mm) to obtain a rod-like extruded product. The inner diameter of the cylinder was 30 mm, the load applied to the piston was 100 kN, and the average surface pressure applied to the piston at this time was 142 MPa.

  The resulting molded body was confirmed to have a fiber structure derived from the cedar and Moso bamboo. Since this fiber structure is considered to favorably affect the properties of the molded body, it has been shown that the present molding method can be expected to have a superior advantage over the powdered molding method.

  As described above in detail, the present invention relates to a plant-based hot-press molding material having fibers and a method for producing the same, and according to the present invention, only a plant material such as wood or bamboo is used as a raw material, and a powdering process is performed. Without passing through, it becomes possible to produce and provide a molding material containing a fiber having a complicated three-dimensional shape. In the present invention, it is possible to provide an alternative material of a conventional material made of metal or plastic as a raw material in a form corresponding to environmental and resource problems. INDUSTRIAL APPLICATION This invention is useful as what makes it possible to provide the new raw material and new product which consist of a plant-type material produced with the shaping | molding technique using the high-strength fiber structure of a raw material.

The SEM image which looked at the cross section of the bamboo basket from diagonally upward is shown. P represents parenchymal cells and F represents a bundle of fiber cells (filament bundle sheath). The distribution of parenchyma cells and fiber cells in the cross section of bamboo basket is shown. The ratio of fiber cells F is large on the epidermis side, and the ratio of parenchymal cells P is large on the lumen side. The disk-shaped bamboo piece cut out from the buttocks of Mosouchiku with a circle cutter and its fiber direction are shown. An outline of the molding process by injection molding is shown. The molded object obtained by injection molding is shown. The micrograph inside the molded object observed by cut | disconnecting the produced molded object is shown. An outflow (extruded product) from a capillary obtained by flowing a bamboo piece from the outer skin side with many fiber cells and a bamboo piece from the lumen side with many parenchymal cells is shown.

Claims (6)

The plant material having fibers as a raw material, without passing through the powdered step by grinding, solidified using a self-adhesive material fiber, formed by a plant-based molding having fibers arbitrary three-dimensional shape is imparted Body,
In the plant material with fibers, the raw fibers in a state of holding the, the material was expressed while flowability was holding the fibers by the application of heat and pressure, any thermally molding by mold plant-base molded article having a fiber characterized in that the three-dimensional shape is imparted.   The plant-based molded article having fibers according to claim 1, wherein the plant-based material having fibers is bamboo, wood, and / or vegetation. Plant based molded body having fibers arbitrary three-dimensional shape is imparted, an intermediate material or molded products, plant-based molded article having a fiber according to claim 1.   Without pulverizing the plant-based material having fibers, the plant-based material is caused to exhibit fluidity while holding the fibers by applying heat and pressure, and the material is poured into a mold and pressed. A method for producing a plant-based molded article having fibers, characterized in that a molded article containing fibers having an arbitrary three-dimensional shape is obtained by utilizing the self-adhesiveness of raw fiber.   The manufacturing method of the plant-type molded object which has a fiber of Claim 4 which carries out injection molding of the plant-type material which has the said fiber, and obtains a molded object.   The manufacturing method of the plant-type molded object which has a fiber of Claim 4 which extrudes the plant-type material which has the said fiber, and obtains a molded object.