JP3886926B2 - Manufacturing method of fibrous molded article - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an improvement in a technique for forming a fiber material such as wood chip, grass, and straw into a molded product in order to effectively use the material.
[0002]
[Prior art]
Fibrous materials such as wood chips, grass, and straw are effectively used for paper products, wooden products, building materials, etc., but polymer resins such as phenol resins, urea resins, acrylic resins, etc., are used as binders. It is common. However, when a polymer resin is used, reuse (recycling) and disposal become difficult.
[0003]
Therefore, a technique using a lignophenol derivative which is a natural substance extracted from a tree instead of a polymer resin has been proposed (for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-9-278904 (paragraph number [0025], FIGS. 6 to 10)
[0005]
FIG. 6 of Patent Document 1 is positioned as a representative example of the prior art and will be described in detail.
FIG. 5 is a reprint of FIG. 6 of Patent Document 1. In Patent Document 1, paragraph number [0025] lines 3 to 6, “..., a cellulosic fiber is molded, and a lignophenol derivative is formed on this molded body. After impregnating the solution, the solvent is distilled off. By distilling off the solvent, the lignophenol derivative exhibits caking properties and exhibits adhesiveness to the molding material. Basically, the molded body is immersed in the lignophenol derivative solution.
[0006]
[Problems to be solved by the invention]
When the molded body is immersed in the lignophenol derivative solution, the penetration of the solution naturally proceeds from the surface of the molded body toward the center. However, since the molded body is dense to some extent, the permeation rate is low and it takes time to permeate to the center. Productivity decreases when time is required.
[0007]
In addition, since the lignophenol derivative solution fills the container and the molded body is immersed therein, it is necessary to prepare a lignophenol derivative solution having a volume several times larger than the molded body volume, and waste such as remaining in the container. Will occur. By the way, if lignophenol derivatives are prepared in large quantities or waste is generated, the product cost increases.
[0008]
Accordingly, an object of the present invention is to provide a production method capable of enhancing productivity on the premise of using a lignophenol derivative and eliminating waste of the lignophenol derivative.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, claim 1 provides a preparation step of preparing a fibrous material, a lignophenol derivative, alcohol, an injection mechanism, and a mold, and a lignophenol-alcohol solution obtained by dissolving the lignophenol derivative with alcohol. And supplying the fibrous material to the injection mechanism, and plasticizing to impregnate the fibrous material with the lignophenol derivative while dissolving the fibrous material with alcohol by kneading with a screw inside the heating cylinder of the injection mechanism A method of manufacturing a fibrous molded article comprising: a step; an injection step of injecting a plasticized fibrous material into a mold; and a molding step of evaporating alcohol from a gap between the molds and urging molding inside the mold. is there.
[0010]
First, by adopting an injection molding method, a large amount of molded products can be produced efficiently.
In the injection mechanism, since the fibrous material is sufficiently impregnated with the lignophenol derivative in the plasticizing step, the lignophenol derivative can be evenly blended from the surface to the center of the molded product. The fibrous material can be formed into a molded article by the binding action of the lignophenol derivative.
[0011]
Lignophenol derivatives are natural substances extracted from trees, and fibrous materials are also natural substances. Therefore, when a fibrous molded article is discarded in the ground, it can be returned to the soil with the help of bacteria and the like. Alternatively, the fibrous molded product can be recycled.
[0012]
According to a second aspect of the present invention, in the preparation step, the fibrous material is prepared in a proportion of 70 to 95 mass%, the lignophenol derivative is prepared in a proportion of 30 to 5 mass%, and the alcohol is prepared in a proportion of 100 to 500 mass%.
[0013]
Alcohol exhibits the effect of increasing the fluidity by dissolving the fibrous material. If the alcohol is less than 100% by mass, that is, less than the amount obtained by adding the lignophenol derivative to the fibrous material, the desired fluidity cannot be obtained, the flow resistance in the injection mechanism increases, and the injection process becomes difficult to perform.
[0014]
If the alcohol content exceeds 500% by mass, that is, exceeds 5 times the amount of the lignophenol derivative added to the fibrous material, a large amount of alcohol evaporates in the process of promoting molding inside the mold, resulting in a molded product. Many fine cavities are generated, and the molded product tends to collapse. That is, the strength of the molded product is significantly reduced.
Therefore, the alcohol is 100 to 500% by mass.
[0015]
When the proportion of the lignophenol derivative is less than 5% by mass, the gloss of the surface of the molded article becomes poor, and the wood texture is impaired.
The lignophenol derivative also serves as a binder for binding the fibrous material. When the ratio of the lignophenol derivative is less than 5% by mass, the bonding force becomes insufficient, the strength of the molded product becomes insufficient, and the molded product is easily broken. In order to enhance the wood texture and ensure the strength, the ratio of the lignophenol derivative needs to be 5% by mass or more.
[0016]
On the other hand, since the lignophenol derivative is a soft material, the strength of the molded product decreases as the ratio increases at 15% by mass or more. As a result of experiments and studies by the present inventors, it has been found that when the proportion of the lignophenol derivative exceeds 30% by mass, the strength of the molded product becomes insufficient. Therefore, the proportion of lignophenol derivative needs to be 30% by mass or less.
[0017]
According to claim 2, molding is started by setting the fibrous material to 70 to 95% by mass, the lignophenol derivative to 30 to 5% by mass, and the alcohol to 100 to 500% by mass. It is possible to obtain a molded product having a functional material of 70 to 95% by mass and a lignophenol derivative of 30 to 5% by mass. This molded product has a good wood texture and a sufficient strength can be expected.
[0018]
According to a third aspect of the present invention, the temperature of the mold is maintained at 170 to 200 ° C. in the molding step.
[0019]
If the temperature of the mold is less than 170 ° C., the evaporation of alcohol slows down and the productivity decreases. Further, when the mold temperature exceeds 200 ° C., the lignophenol derivative may be altered. Therefore, the mold temperature is maintained at 170 to 200 ° C.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the accompanying drawings. The drawings are viewed in the direction of the reference numerals.
FIG. 1 is a cross-sectional view of an injection mechanism used in the present invention. An injection mechanism 10 includes a heating cylinder 11, a screw 12 attached to the heating cylinder 11 so as to be rotatable and capable of moving forward and backward, and the screw 12 is moved back and forth. A hydraulic cylinder 13 as a screw forward and backward advance means, a screw rotating means 15 for rotating the screw 12 by rotating a piston 14 of the hydraulic cylinder 13, and a base of the screw 12 to detect the position of the screw 12 A screw position detecting means 16 for performing the operation, a nozzle valve 17 provided at the tip of the heating cylinder 11, a hopper 18 connected to the base of the heating cylinder 11, a feed screw 21 inserted in a reduced diameter portion 19 of the hopper 18, Agitation blades 23 and 24 attached to the shaft 22 of the feed screw 21, and the lid 2 on the upper part of the hopper 18 A feed motor 26 attached to a material supply pipe 27 and the solution supply pipe 28 connected to the lid 25, each consisting of provided a gate valve 31 and 32 Metropolitan these material supply pipe 27 and the solution supply pipe 28.
[0021]
The mold 40 includes a fixed mold 41, a movable mold 42, and a cavity 43 formed therebetween. The mold clamping mechanism was omitted.
[0022]
Next, a method for manufacturing a fibrous molded article of the present invention, which is performed using the injection mechanism 10 and the mold 40 having the above-described configuration, will be described.
FIG. 2 is a production flow diagram suitable for producing the fibrous molded article of the present invention, and will be described with reference to FIG. STxx indicates a step.
[0023]
ST01: A fibrous material, a lignophenol derivative, alcohol, an injection mechanism, and a mold are prepared.
ST02: A lignophenol / alcohol solution is prepared by dissolving a lignophenol derivative in alcohol. The mixing ratio will be described later.
[0024]
The lignophenol derivative can be produced in the following manner.
Woody materials such as wood flour, chips, waste wood, and wood fragments are lignocellulosic materials containing lignin. When this material is treated with a phenol derivative such as cresol, the material dissolves and lignin is extracted as a lignophenol derivative. be able to.
[0025]
Alcohol is based on low-boiling alcohols such as methanol, ethanol, and propanol, and can be substituted for ketones such as acetone and methyl ethyl ketone. Furthermore, the alcohol may be an industrial alcohol containing water or a ketone.
[0026]
ST03: Supply the same solution (lignophenol / alcohol solution) and fibrous material to the hopper. The fiber material is not limited as long as it is a wood grass piece such as wood powder, chip, waste material, wood piece, and grass. In FIG. 1, the fibrous material is supplied to the hopper 18 through the material supply pipe 27 as indicated by the arrow (1), and at the same time, the lignophenol / alcohol solution is supplied to the hopper 18 through the solution supply pipe 28 as shown by the arrow (2). .
[0027]
ST04: Stir the inside of the hopper. That is, in FIG. 1, the stirring blades 23 and 24 are rotated by the action of the feed motor 26 to stir and bring the lignophenol / alcohol solution into sufficient contact with the fibrous material.
[0028]
ST05: Feed the stirred material to the heating cylinder. That is, the material is pushed into the heating cylinder 11 by the pushing action of the feed screw 21 rotated by the feed motor 26 in FIG.
[0029]
ST06: Kneading in a heating cylinder. That is, when the screw 12 is rotated at a predetermined number of revolutions in FIG. 1, the material moves along the groove of the screw 12 toward the tip. Although material accumulates at the tip, the screw 12 moves backward in accordance with the accumulated amount.
[0030]
In the heating cylinder 11, the kneading proceeds while the material is compressed between the heating cylinder 11 by the action of the screw 12. At this time, the alcohol penetrates into the fibrous material, the preferred temperature and the preferred compression are applied, and the fibrous material melts. The lignophenol derivative is evenly mixed with the melted fibrous material.
[0031]
ST07: Next, injection is executed. That is, the nozzle valve 17 is opened in FIG. The melted material is filled in the cavity 43 of the mold 40 by the extrusion action of the screw 12.
[0032]
ST08: The alcohol is evaporated from the molded body. That is, when the mold 40 is kept at 170 to 200 ° C. in FIG. 1, the alcohol is actively evaporated and escapes from the gap between the fixed mold 41 and the movable mold 42 to the outside of the mold.
[0033]
ST09: When alcohol is sufficiently removed, the mold is opened and the fibrous molded article is taken out.
The base material constituting the obtained fibrous molded article is a natural material made of trees and grass, and the binder is a lignophenol derivative extracted from the tree and is a natural material. As a result, the fiber molded article can be returned to the soil by discarding the soil, and diverted to the paper stock by crushing can be achieved recycling.
[0034]
The blending of raw materials is important when carrying out the present invention, and will be described below.
FIG. 3 is a graph showing the relationship between the ratio of the lignophenol derivative and the gloss of the molded product.
The horizontal axis indicates the ratio of lignophenol derivative (upper) and fibrous material (lower), and the vertical axis indicates the gloss of the molded product. Fibrous materials represented by wood chips have poor luster. On the other hand, lignophenol derivatives exhibit a gloss effect. The total of the lignophenol derivative and the fibrous material was set to 100% by mass, and the gloss of the molded product was examined by changing the combination of both.
[0035]
As shown in the graph, it was confirmed that the required gloss could be secured if the ratio of the lignophenol derivative was 5% by mass or more. Therefore, the minimum value of the lignophenol derivative ratio is set to 5% by mass, and the maximum value of the fibrous material ratio is set to 95% by mass.
[0036]
FIG. 4 is a graph showing the relationship between the ratio of the lignophenol derivative and the strength of the molded product.
The horizontal axis indicates the ratio of the lignophenol derivative and the fibrous material, and the vertical axis indicates the tensile strength of the molded product.
When the total strength of the lignophenol derivative and the fibrous material was 100% by mass and the tensile strength of the molded product was examined by variously changing the blending of both, it was found that an angled curve was drawn.
[0037]
Since the fibrous molded product is assumed to be furniture or woody tableware, it must be strong enough to withstand handling. A line parallel to the vertical axis is drawn from 5% by mass of the lignophenol derivative on the horizontal axis, and the point where the curve intersects is defined as P1. In the inventors' research, the tensile strength at this point P1 can be regarded as the necessary strength.
[0038]
A horizontal line passing through the point P1 is drawn, and a new point intersecting with the horizontal line is defined as P2. This point P2 corresponds to 30% by mass on the horizontal axis. That is, it can be said that the required strength can be exhibited by setting the ratio of the lignophenol derivative to 5 to 30% by mass.
[0039]
And when higher intensity | strength is requested | required, it can be said that preferable intensity | strength can be exhibited by making the ratio of a lignophenol derivative into 10-25 mass% like illustration.
[0040]
Therefore, it is effective that the fibrous material is 70 to 95% by mass and the lignophenol derivative is 30 to 5% by mass, preferably the fibrous material is 75 to 90% by mass and the lignophenol derivative is 25 to 10% by mass. And
[0041]
Alcohol is a solvent that does not remain in the molded article. When the total of the fibrous material and the lignophenol derivative is 100% by mass, the alcohol is 100 to 500% by mass, that is, 1.0 times to the total. Add 5.0 times. The reason is as follows.
[0042]
Alcohol exhibits the effect of increasing the fluidity by dissolving the fibrous material. If the alcohol is less than 100% by mass, that is, less than the amount obtained by adding the lignophenol derivative to the fibrous material, the desired fluidity cannot be obtained, the flow resistance in the injection mechanism increases, and the injection process becomes difficult to perform.
[0043]
If the alcohol content exceeds 500% by mass, that is, exceeds 5 times the amount of the lignophenol derivative added to the fibrous material, a large amount of alcohol evaporates in the process of promoting molding inside the mold, resulting in a molded product. Many fine cavities are generated, and the molded product tends to collapse. That is, the strength of the molded product is significantly reduced.
Therefore, the alcohol is 100 to 500% by mass.
[0044]
The injection mechanism 10 described with reference to FIG. 1 is merely an example, and may be an all-electric injection mechanism.
The flow described with reference to FIG. 2 is merely an example, and it is possible to increase or decrease the number of steps and change the contents of steps within a range that does not change the gist of the invention.
[0045]
【The invention's effect】
The present invention exhibits the following effects by the above configuration.
The manufacturing method according to claim 1 enables injection molding by dissolving a fibrous material with alcohol to enhance fluidity. By adopting the injection molding method, a large amount of molded products can be produced efficiently.
[0046]
In the injection mechanism, since the fibrous material is sufficiently impregnated with the lignophenol derivative in the plasticizing step, the lignophenol derivative can be evenly blended from the surface to the center of the molded product. The fibrous material can be formed into a molded article by the binding action of the lignophenol derivative. Since the lignophenol derivative can be used up, there is no worry of wasting the lignophenol derivative.
[0047]
Lignophenol derivatives are natural substances extracted from trees, and fibrous materials are also natural substances. Therefore, when a fibrous molded article is discarded in the ground, it can be returned to the soil with the help of bacteria and the like. Alternatively, the fibrous molded product can be recycled.
[0048]
According to a second aspect of the present invention, in the preparation step, the fibrous material is prepared in a proportion of 70 to 95 mass%, the lignophenol derivative is prepared in a proportion of 30 to 5 mass%, and the alcohol is prepared in a proportion of 100 to 500 mass%.
[0049]
Alcohol exhibits the effect of increasing the fluidity by dissolving the fibrous material. If the alcohol is less than 100% by mass, that is, less than the amount obtained by adding the lignophenol derivative to the fibrous material, the desired fluidity cannot be obtained, the flow resistance in the injection mechanism increases, and the injection process becomes difficult to perform.
[0050]
If the alcohol content exceeds 500% by mass, that is, exceeds 5 times the amount of the lignophenol derivative added to the fibrous material, a large amount of alcohol evaporates in the process of promoting molding inside the mold, resulting in a molded product. Many fine cavities are generated, and the molded product tends to collapse. That is, the strength of the molded product is significantly reduced.
Therefore, the alcohol is 100 to 500% by mass.
[0051]
When the proportion of the lignophenol derivative is less than 5% by mass, the gloss of the surface of the molded article becomes poor, and the wood texture is impaired. The lignophenol derivative serves as a binder for binding the fibrous material. When the ratio of the lignophenol derivative is less than 5% by mass, the bonding force becomes insufficient, the strength of the molded product becomes insufficient, and the molded product is easily broken. In order to enhance the wood texture and ensure the strength, the ratio of the lignophenol derivative needs to be 5% by mass or more.
[0052]
On the other hand, since the lignophenol derivative is a soft material, the strength of the molded product decreases as the ratio increases at 15% by mass or more. As a result of experiments and examinations by the present inventors, it has been found that when the proportion of the lignophenol derivative exceeds 30% by mass, the strength of the molded product becomes insufficient. Therefore, the proportion of lignophenol derivative needs to be 30% by mass or less.
[0053]
Therefore, in claim 2, molding is started by setting the fibrous material to 70 to 95% by mass, the lignophenol derivative to 30 to 5% by mass, and the alcohol to 100 to 500% by mass. A molded product having a fibrous material content of 70 to 95% by mass and a lignophenol derivative of 30 to 5% by mass can be obtained. The molded product has a good wood texture and a sufficient strength can be expected.
[0054]
According to a third aspect of the present invention, the temperature of the mold is maintained at 170 to 200 ° C. in the molding step.
If the temperature of the mold is less than 170 ° C., the evaporation of alcohol slows down and the productivity decreases. Further, when the mold temperature exceeds 200 ° C., the lignophenol derivative may be altered. Therefore, the mold temperature is maintained at 170 to 200 ° C.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of an injection mechanism used in the present invention. FIG. 2 is a production flow chart suitable for producing a fibrous molded article of the present invention. FIG. 4 is a graph showing the relationship between the proportion of lignophenol derivatives and the strength of the molded product. FIG. 5 is a reprint of FIG. 6 of Patent Document 1.
DESCRIPTION OF SYMBOLS 10 ... Injection mechanism, 11 ... Heating cylinder, 12 ... Screw, 28 ... Solution supply pipe (lignophenol / alcohol solution supply pipe), 40 ... Mold.

Claims (3)

Preparation process for preparing fibrous material, lignophenol derivative, alcohol, injection mechanism and mold, supply of lignophenol / alcohol solution prepared by dissolving lignophenol derivative with alcohol, and supply of said fibrous material to injection mechanism A plasticizing process in which the fibrous material is impregnated with the lignophenol derivative while dissolving the fibrous material with alcohol by carrying out kneading with a screw inside the heating cylinder of the injection mechanism, and the plasticized fibrous material is made of gold A method for manufacturing a fibrous molded article, comprising: an injection process for injecting a mold; and a molding process for promoting molding inside the mold while evaporating alcohol from a gap between the molds. 2. The fibrous molding according to claim 1, wherein in the preparation step, the fibrous material is prepared in a proportion of 70 to 95 mass%, the lignophenol derivative is 30 to 5 mass%, and the alcohol is 100 to 500 mass%. Product manufacturing method. The method for producing a fibrous molded article according to claim 1 or 2, wherein in the molding step, the temperature of the mold is maintained at 170 to 200 ° C.

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