JP4794076B2 - Manufacturing method of wood-based hot-press molding material - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a wood-based molding material having an arbitrary three-dimensional shape, which is an alternative to plastics. More specifically, the present invention relates to a steam treatment at a predetermined temperature for a wood-based material such as wood powder. A method for producing a new wood-based molding material and a wood-based material that can provide a fluidity by applying an arbitrary three-dimensional shape to a wood-based material such as wood powder, and a wood-based material are provided. The present invention relates to a new type of wood-based molding material that can cope with resource and environmental problems without impairing the inherent biodegradability advantage.
[0002]
[Prior art]
Among wood-based materials, wood is a material with high workability, and is a material that is widely used by processing methods such as “cut”, “shave”, and “join”. In some cases, the wood is used as a face material having a large area or a very long shaft material, and in this case, the wood is finely bonded to a certain degree and “glued”. 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, conventionally, in order to produce a product with an arbitrary three-dimensional shape, a large amount of resin is mixed into finely pulverized wood to make the raw material flowable, melted, poured into a mold, and cooled.・ Molding process to solidify is performed.
The literature related to the above prior art is exemplified below.
(1) The Wood Society of Japan: “Processing of wood”, Bunnendo Publishing, pp. 1-9 (1991)
(2) The Wood Society of Japan: “A wonderful world of wood”, Kaiseisha, pp. 46-49 (1995)
(3) The Wood Society of Japan: “Wood Resource Materials”, Kaiseisha, pp. 139-186 (1999)
[0003]
However, in the case of the conventional molding technology, in order to produce a material having a complicated three-dimensional shape by giving the raw material fluidity and pouring the raw material to every corner of the mold, the resin is added to the raw material in a weight ratio of 40. % Should be mixed.
In this way, the conventional molding technology is based on mixing finely pulverized wood with a large amount of resin and hardening it, and it detracts from the inherent biodegradability of wood. Problems arise during disposal. In addition, since it is impossible to separate a mixed material of wood and resin into wood and resin, a problem occurs during recycling. In addition, since there is currently a concern about the depletion of reserve resources, in molding technology using resins derived from reserve resources, it is necessary to devise measures to reduce the proportion of resin as much as possible. It has become to.
[0004]
[Problems to be solved by the invention]
Under such circumstances, the present inventors have conducted intensive research with the goal of manufacturing a new wood-based molding material that can cope with resource and environmental problems by taking advantage of the biodegradability of the wood-based material. As a result of stacking, it has been found that the intended purpose can be achieved by forming the raw material with fluidity by subjecting a woody material such as wood flour to steam treatment at a predetermined temperature, and forming this material. The invention has been completed.
The present invention uses only wood, which is a reproducible resource, as a raw material, and forms a material with a complicated three-dimensional shape without using an adhesive in a form with a small environmental load without mixing a resin. It aims at providing the manufacturing method of the wood type molding material which consists of these.
Another object of the present invention is to provide a method for producing a wood-based molding material having an arbitrary three-dimensional shape, which is an alternative to plastics, by a simple operation.
[0005]
[Means for Solving the Problems]
The present invention for solving the above-described problems comprises the following technical means.
(1) Finely pulverize the wood-based material to make a fine powder, which is treated with water vapor to soften it to have fluidity, and then poured into a mold and hot pressed, or the fine powder is put into a mold, A method of producing a plastic-like woody molding material having an arbitrary three-dimensional shape by pressing and molding while performing steam treatment, and then cooling and solidifying ,
The wood-based material is finely pulverized to a particle size of 0.1 to 1500 μm, and the particle size is adjusted to 1 to 1000 μm by classification to obtain a fine powder, which is pressed at a pressure of at least 50 MPa to flow the wood powder. A method for producing a wood-based molding material, characterized in that it is formed by molding.
(2) the wood-based material, adjust the particle size to ninety to three hundred and fifty-five [mu] m by finely ground, and classified method woody molding material according to (1).
( 3 ) The method for producing a wood-based molding material according to (1), wherein the water vapor is in a temperature range of 170 to 230 ° C.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Next, the present invention will be described in more detail.
The present invention improves the flowability by treating the fine powder of the wood-based material as a raw material with water vapor, and then press-fits into a mold to cool and solidify the wood to give an arbitrary three-dimensional shape It is characterized by producing a system molding material.
In the present invention, the raw material woody material may be an appropriate one, and is not particularly limited. The fine powder of the wood-based material is produced, for example, by pulverizing a wood chip with a spiral mill or the like in a dried state and classifying with a sieve. In this case, preferably, the shape of the wood powder particles is close to a sphere and is not long and is finely divided to a particle size of 0.1 to 1500 μm, and is classified to a particle size of 1 to 1000 μm. It is desirable that it is adjusted.
[0007]
Next, this wood powder is treated with water vapor to soften it to have fluidity, and after pouring into the mold, it is hot pressed, or the wood powder is placed in the metal mold and pressed while performing the water vapor treatment. , Forming process. In this case, for example, a piston cylinder mold is preferably used as the mold. However, any mold may be used as long as it can extrude or injection-mold wood powder, and is not particularly limited. . The pressure for pressing is about 50 MPa, more preferably 100 MPa or more. Here, the steam treatment means that the wood powder is exposed to steam at a certain temperature for a certain period of time. For example, the pressure vessel containing the wood powder is filled with high-temperature steam and treated for a certain time.
For example, the water vapor treatment is performed for about 30 minutes, and the water vapor treatment may be performed by reducing the hardness of the wood powder particles to fluidize the wood powder, and the treatment time is not particularly limited. Next, this is cooled to room temperature (about 20 ° C.) and solidified to produce a material having a desired three-dimensional shape.
[0008]
According to the method for producing a wood-based molding material of the present invention, for example, wood powder particles can be softened by subjecting the wood powder to steam treatment, thereby improving the fluidity of the wood powder. After that, by pressing the wood powder into the mold, the fine powder of the wood-based material that is the raw material is distributed to every corner of the mold, and by cooling and solidifying this, a complicated three-dimensional shape is given The molded material can be molded and produced.
The temperature of the water vapor is preferably 170 ° C. or higher, more preferably 180 to 230 ° C., whereby the fine powder particles of the wood-based material are remarkably softened, and the fluidity of the wood powder can be greatly improved. In this case, when the temperature is lower than 170 ° C., the fine powder particles of the wood-based material are not softened so much and the fluidity of the wood powder cannot be sufficiently improved.
In the present invention, the fine powder of the wood-based material that is a raw material is not particularly limited to wood powder. For example, the production method of the present invention is applicable to plants in general that grow by fixing carbon by photosynthesis. Is applicable.
[0009]
By replacing the wood-based molding material according to the present invention with a material made of metal or plastic as a raw material, it becomes possible to reduce the environmental burden at the time of product disposal, and at the same time, a resin is used for the wood-based molding material. Since it is not mixed, the problem of separating wood and resin during recycling can be avoided. Furthermore, since the wood-based molding material of the present invention uses only plant materials such as wood, which is a reproducible resource, as a raw material, it can be a fundamental solution to the resource problem.
By using the wood-based molding material obtained by the present invention as a substitute for a material manufactured using metal or plastic as a raw material, for example, as a substitute for a housing of an appliance, so-called resources / It can be expected to be a solution to environmental problems.
[0010]
[Action]
In the present invention, a woody material such as wood powder is subjected to water vapor treatment at a predetermined temperature so as to have fluidity, and is poured into a mold and hot pressed, or a fine powder is put into a mold, The wood-based molding material to which an arbitrary three-dimensional shape is imparted is produced by pressing and molding while performing the water vapor treatment, and then cooling and solidifying. For example, the wood powder pulverized to a predetermined particle size is subjected to steam treatment at a temperature of 170 ° C. or more, more preferably 180 to 230 ° C., thereby softening the wood powder particles, thereby allowing the wood powder to flow. By improving the properties, wood powder can reach every corner of the mold, and by cooling and solidifying it, it is molded into a material that has a complex shape corresponding to the complex three-dimensional shape of the mold It becomes possible to process. The fluidity of wood flour can be improved by adjusting the temperature of the steam treatment to a predetermined temperature range, and the elastic modulus and bending strength of the molded body can be improved by adjusting the wood powder particle size to a predetermined range. Can be controlled.
[0011]
【Example】
EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited at all by the following examples.
Example 1
(1) Production method A mixed chip of cedar and cypress was pulverized using a spiral mill in a state dried at 100 ° C., and classified by sieving to obtain raw wood flour. The particle size of the prepared wood flour is 250 to 355 μm. As shown in FIG. 1, a mold A, a mold B, and 1.5 g of wood flour were put in this order in the mold C, subjected to a steam treatment for 30 minutes, and then pressed for 5 minutes. When the wood powder was distributed to every corner of the mold and the molding was completed, a T-shaped molded body was obtained. The pressing pressure is 139 MPa. In consideration of workability and future environmental problems, no adhesive was used.
[0012]
(2) The resulting molded product is shown in FIG. In the figure, the steam treatment temperatures are 80, 130, and 175 ° C. in order from the top. In the case of steam treatment at 80 ° C., the wood powder hardly flows in the mold, but as the steam treatment temperature increases, the wood powder flows to every corner in the mold, and the steam treatment at 175 ° C. In the case of, it can be seen that the wood powder is completely distributed to every corner of the mold. Thereby, it was found that the steam treatment at a sufficient temperature is effective in improving the fluidity of the wood flour.
[0013]
Example 2
(1) Production method A mixed chip of cedar and cypress was pulverized using a spiral mill in a state dried at 100 ° C., and classified by sieving to obtain raw wood flour. The particle size of the prepared wood flour is 90 μm or less, 106 to 150, 150 to 180, 180 to 250, 250 to 355 μm. After putting 1.5 g of wood powder into a mold and performing a water vapor treatment for 30 minutes, a 30-minute pressing was performed to produce a circular cross-section bar (cross-sectional diameter 3 mm, length 30 mm). The pressing pressure is 139 MPa. In consideration of workability and future environmental problems, no adhesive is used. The produced circular cross-section bar was subjected to a three-point bending test with a central concentrated load, and the elastic modulus and bending strength were examined.
[0014]
(2) Results FIG. 3 shows the relationship between the wood particle diameter, the bulk density, and the elastic modulus among the bending test results of the molded body. Even if the wood powder particle size changes, the bulk density of the molded body hardly fluctuates, but the elastic modulus fluctuates greatly, and shows a maximum value of 4 GPa when the wood powder particle size is 150 to 180 μm. FIG. 4 shows the relationship between the particle size of wood powder, bulk density and bending strength. As for the bending strength, the same tendency as the previous elastic modulus is observed, and the bulk density of the molded body hardly fluctuates even if the wood powder particle size changes, but the bending strength greatly fluctuates and the wood powder particle size In the case of 150 to 180 μm, the maximum value is 26 MPa.
[0015]
FIG. 5 shows an SEM of the fracture surface of the specimen after the bending test. Looking at these, the shape of the wood flour that is the raw material remains after molding, and when the wood powder particle size is small, the fiber is short and the gap is small, and when the wood powder particle size is large, the fiber is long. It can be seen that the gap is large. In terms of strength, it is considered that it is advantageous that the fibers are long and the voids are small. However, the result of the bending test shows the maximum value when the particle size of the wood flour is about 106 to 150 μm. This is considered to be due to the balance between the fiber length and the void size.
[0016]
【The invention's effect】
As described above in detail, the present invention finely pulverizes a wood-based material to give a fine powder, which is softened by treatment with water vapor, for example, poured into a mold and hot-pressed, The present invention relates to a method for producing a wood-based molding material having an arbitrary three-dimensional shape, which is characterized by being cooled and hardened after molding. According to the present invention, 1) an arbitrary third order which is an alternative to plastics A new type of wood-based molding material with the original shape can be produced. 2) Using only plant materials such as wood as raw materials, it is possible to produce a molding material with a complicated three-dimensional shape by a simple operation. 3) By using the method for producing a wood-based molding material of the present invention, it becomes possible to produce an alternative material made of metal or plastic as a raw material in a form corresponding to environmental and resource problems. 4) Waste generated in large quantities It is useful as a method of recycling wood, special effect can be obtained.
[Brief description of the drawings]
FIG. 1 shows a procedure for forming wood flour by the production method of the present invention.
FIG. 2 shows the difference between molded bodies produced by varying the steam treatment temperature.
FIG. 3 shows the relationship between the particle size, the bulk density, and the elastic modulus of a fine powder of a wood-based material of a molded body produced by the production method of the present invention.
FIG. 4 shows the relationship between the particle size, bulk density, and bending strength of a fine powder of a wood-based material of a molded body produced by the production method of the present invention.
FIG. 5 shows an SEM of a three-point bending fracture surface of a molded body produced by the production method of the present invention.

Claims (3)

Finely pulverize the wood-based material and treat it with water vapor to soften it to make it flowable, then pour it into the mold and heat-press it, or place the fine powder into the mold and perform the water vapor treatment. A method of producing a plastic-like wood-based molding material having an arbitrary three-dimensional shape by pressing and molding while performing, then cooling and solidifying ,
The wood-based material is finely pulverized to a particle size of 0.1 to 1500 μm, and the particle size is adjusted to 1 to 1000 μm by classification to obtain a fine powder, which is pressed at a pressure of at least 50 MPa to flow the wood powder. A method for producing a wood-based molding material, characterized in that it is formed by molding. The wood-based material, finely pulverized, and you adjust the particle size 90-355 [mu] m by classification method for producing a woody molded material according to claim 1.   The method for producing a woody molding material according to claim 1, wherein the water vapor is in a temperature range of 170 to 230 ° C.

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