JP2002167514A - Wood meal-based composite - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody substance-based composite which is capable of improving space efficiency, facility cost, productivity and product yield in a factory as well as is capable of being manufactured by blending a higher content of wood meal. SOLUTION: The woody substance-based composite contains at least a wood meal and a thermoplastic resin, with the content of the wood meal being 70 wt.% to 95 wt.%, preferably 80 wt.% to 85 wt.%; a product obtained is the one by conveying as a solid the wood meal dispersing a small amount of a resin therein and by compressing and then pressing both together by the pressure in a metal die of a conical-type twin screw extruder. This method results in no necessity of a cooling apparatus posterior to the discharge from the metal die (since a molded article has been pressed together at the time of being extruded off) and in the omission of a water-cooling process and a sizing process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a wood-based composite material containing wood flour.

[0002]

2. Description of the Related Art Conventionally, when extruding a wood flour composite using a raw material obtained by mixing wood flour and a resin, the wood flour, the resin, and the compatibilizer are agitated and granulated. The extruder is used to extrude the raw material (hereinafter referred to as agglomerate granules) into a predetermined shape to obtain a product.
As long as a normal single-screw or twin-screw extruder is used, the compounding ratio of wood powder is less than 70%, which is the limit at which extrusion molding is possible. Therefore, the compounding ratio of resin is necessarily 30%.
I have to do more.

[0003] As described above, since the compounding ratio of the resin has conventionally been limited to 30% or more, the particle size of the agglomerate particles becomes too large during stirring and granulation. For this reason, a pulverizing step for pulverizing the agglomerate particles to an appropriate size is indispensable between the stirring step and the charging step into the extruder. In addition, a water-cooling step of cooling the product extruded at the subsequent stage of the extruder in a cooling tank in order to quickly solidify the resin melted in the product extruded from the extruder and give the product a predetermined shape. Is also essential.

[0004]

However, in the prior art, the production line becomes longer due to the presence of a water-cooling step requiring a pulverizing step and a cooling tank, which leads to a reduction in space efficiency of the factory and an increase in equipment costs. Resulting in. In addition, the line speed is limited according to the cooling efficiency in the water cooling process, which causes a decrease in productivity, and also causes a disadvantage that the product is deformed due to post-shrinkage due to insufficient cooling and the yield is reduced. is there.

[0005] Further, from the viewpoint of effective use of wood flour or pseudo-wood of wood flour-based composite material, a higher concentration of wood flour is expected to be blended. It was not able to meet such expectations.

The present invention has been made in view of such conventional problems, and can improve the space efficiency, equipment cost, productivity, and product yield of a factory, and can improve the concentration of a higher concentration. It is an object of the present invention to provide a wood-based composite material that can be manufactured by blending wood flour.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, a wood-based composite material according to the present invention contains at least wood flour and a thermoplastic resin, and has a wood flour content of 70%.
Wt% to 95 wt%, preferably 80 wt% to 85 wt%
% By weight.

That is, conventionally, a single-screw or twin-screw extruder has been used for extrusion molding. However, as a result of research, the present inventor has found that the use of a conical twin-screw extruder can maximize the wood flour concentration. He came up with something that could be raised to 95%. This means that the extruding behavior of the wood flour could be made completely different from the conventional one, not only by increasing the compounding concentration of the wood flour. That is, conventionally, 30
% Or more of the resin was melted in the extruder, and the entire raw material was extruded as one fluid and solidified by cooling. However, in the case of the present invention using a high-concentration raw material of wood flour, wood flour in which resin is slightly dispersed is conveyed and compressed as a solid, and is compacted by pressure in a die of a conical twin-screw extruder. Product will be obtained.

As a result, a cooling device after leaving the mold die becomes unnecessary (since the molded product is compacted at the time of extrusion), and the water cooling process and the sizing process can be omitted. became. In addition, since the pushing force is strong (the molded article is compacted when it comes out of the die), a take-up machine is not required. As a result, the production line is shortened, the space efficiency of the factory and the equipment cost are improved, and further, the productivity is improved without the line speed being restricted according to the cooling efficiency in the water cooling process. The yield is improved without deformation of the product due to post-shrinkage due to shortage. Also, when granulating,
The particle size of the agglomerate particles does not become unnecessarily large during stirring granulation, and a pulverizing step for pulverizing the agglomerate particles to an appropriate size is not required. This also shortens the production line and improves the space efficiency and equipment cost of the factory.

In the present invention, the thermoplastic resin is preferably polypropylene, and the MI value of the polypropylene is 1 to 100, preferably 40 to 50, and the particle size of the wood flour is 1 μm to 10 mm. MI of propylene
If the value is not in the range of 1 to 100, molding becomes impossible, and if the particle size of the wood powder is not in the range of 1 μm to 10 mm, sufficient rigidity of the product cannot be obtained.

In the present invention, a compatibilizer is further contained, and preferably 0.1 to 10% by weight of a maleic anhydride-modified resin is used as the compatibilizer.

Further, the agglomerate particles for wood flour-based composite material according to the present invention contain at least wood flour and a thermoplastic resin, and have a wood flour content of 70% by weight to 95% by weight.
Is granulated to a particle size of 0.1 mm to 30 mm. If the particle size of the agglomerate is less than 0.1 mm, it will not flow in the conical twin-screw extruder and molding will not be possible. Impossible.

[0013]

EXAMPLES Examples of the present invention will be described below along with comparative examples. In the production of the examples and the comparative examples, the production system shown in FIG. 1 was used. The production system includes a Henschel mixer 1 for performing the first step A, a granulated material cooler 2 for performing the second step B,
And a conical twin-screw extruder 3 for executing the third step C. As Henschel mixer 1,
Using "Henschel heater mixer made by Mitsui Mining Company",
As the granulated material cooler 2, a “rotating disk-type mixer (a particle sizer manufactured by Okawara Seisakusho Co., Ltd.)” is used. Was used.

In the first step A, the wood flour 41 and the PP (polypropylene) 4 are mixed in the Henschel mixer 1.
2. A compatibilizer (for example, a maleic anhydride-modified resin) 45 was charged and granulated with stirring. Next, in a second step B, the grown grains were cooled to obtain agglomerate grains 43. Thereafter, in the third step, the agglomerate granules 43 were put into the conical twin-screw extruder 3 from the hopper 31 and extruded from the die 32. Examples-1 to 5 manufactured by this manufacturing system and comparative examples-
Tables 1 and 2 are shown in Table 1 below.

[Table 1]

In Table 1, the blending units of various raw materials are% by weight, and Umex 1010 (manufactured by Sanyo Chemical Co., Ltd.) was used as a compatibilizer. And the above embodiment-
For 1 to 5 and Comparative Examples -1 to 4, the granulation performance and the extrusion molding performance were tested and observed. As a result, Example-1
Both the granulation performance and the extrusion molding performance were extremely good (◎), the granulation could be performed in a short time, the line speed in the third step C was the fastest, and a pseudo-wood product could be formed.

Example 2 in which no compatibilizer was used,
Both the granulation performance and the extrusion molding performance were good (○). That is, the required granulation time was longer than in Example-1, and the line speed in the third step C was slightly lower, but the molded product itself was comparable to Example-1.

Both the average particle size and the particle size range of the wood flour are shown in Example-1.
In Example 3, which was larger than the above, the granulation performance was slightly poor (△).
However, the extrusion molding performance was good (○). That is, the required granulation time was longer than in Example-2, but the line speed in the third step C and the molded product itself were comparable to those of Example-2.

In Example-4, in which the MI value of PP was "10" and the other conditions were the same as in Example-1, the granulation performance was slightly poor (△), but the extrusion molding performance was poor. It was good (O). That is, the required granulation time was longer than in Example-2, but the line speed in the third step C and the molded product itself were comparable to those of Example-2.

In Example 4, in which the water content of the wood flour was "10%" and the other conditions were the same as in Example 1, the granulation performance was slightly poor (△), but the extrusion molding was performed. Good performance (○)
Met. That is, the required granulation time was longer than in Example-2, but the line speed in the third step C and the molded product itself were comparable to those of Example-2.

However, Comparative Example 1 in which the wood flour concentration was 98%
The granulation performance was slightly poor (△), but the extrusion performance was poor (×). That is, although granulation itself was possible, the product could not be extruded into a predetermined shape, and the extrusion molding performance was poor (x).

Comparative Example 2 in which the wood flour concentration was 55%
The granulation performance was slightly poor (△), but the extrusion performance was poor (x). That is, granulation itself was possible, and it was possible to extrude a product into a predetermined shape. However, the manufacturing system (FIG. 1) does not use a cooling device after being extruded from a die. In addition, the extruded product was deformed and could not be formed substantially.

[0022]

As described above, according to the present invention, the mixing ratio of the thermoplastic resin can be relatively reduced, whereby the particle size of the agglomerate particles produced in the course of the production process can be reduced. Can be prevented from becoming unnecessarily large. For this reason, the pulverizing step for pulverizing the agglomerate particles into an appropriate size between the stirring step and the charging step into the extruder can be omitted. In addition, a water-cooling step of cooling the product extruded at the subsequent stage of the extruder in a cooling tank in order to quickly solidify the resin melted in the product extruded from the extruder and give the product a predetermined shape. Can also be eliminated.

Therefore, the space efficiency, equipment cost, and productivity of the factory can be improved, and the yield due to post-shrinkage due to insufficient cooling can be improved, thereby significantly reducing the cost of wood flour. A composite can be provided.

When the cost of wood flour is lower than the cost of thermoplastic resin, the overall manufacturing cost of the product can be reduced, and the mixture of high-concentration wood flour allows the actual wood flour to be mixed. And a product indistinguishable in appearance. Further, the high concentration of wood flour can promote effective use of wood, and in particular, when scrap wood is used as wood flour, can contribute to effective use of earth resources.

[Brief description of the drawings]

FIG. 1 is a diagram showing a manufacturing system used for manufacturing an example of the present invention and a comparative example.

[Explanation of symbols]

 A first step B second step C third step 1 Henschel mixer 2 Air cooling device 3 Conical twin screw extruder

Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat II (Reference) C08L 101: 00) C08L 101: 00) (C08L 97/02 (C08L 97/02 23:10) 23:10) B29K 23 : 00 B29K 23:00 103: 00 103: 00 (72) Inventor Yutaka Nakane No. 1 Tosaka, Kosaka-sha, Kakuda-shi, Miyagi Prefecture F-term in the Iris Oyama Co., Ltd. Kakuda factory (reference) 2B260 AA20 BA02 BA18 DA07 DA18 EA13 EA20 4F070 AA02 AA61 AB09 AB21 AC74 AC75 AC84 AD10 AE30 DA05 DB05 DC07 FA03 FA08 FB06 FC05 FC06 4F201 AA11 AA20 AB01 AD06 AR20 BA02 BC02 BC12 BC15 BC37 BL03 BL44 4J002 AA00Y AA01X AH001 BB12X BB21Y FA001 FD20Y

Claims (7)

[Claims] 1. A wood-based composite material containing at least wood flour and a thermoplastic resin, wherein the wood flour content is 70% by weight to 95% by weight. 2. The wood-based composite material according to claim 1, wherein said thermoplastic resin is polypropylene. 3. The polypropylene according to claim 1, wherein said polypropylene has an MI value of 1 to 1.
The wood-based composite material according to claim 2, wherein the number is 00. 4. The wood-based composite material according to claim 1, wherein the particle size of the wood flour is 1 μm to 10 mm. 5. The wood-based composite material according to claim 1, further comprising a compatibilizer. 6. The wood-based composite material according to claim 5, wherein the content of the maleic anhydride-modified resin is 0.1% by weight to 10% by weight as the compatibilizer. 7. A raw material containing at least wood flour and a thermoplastic resin and having a wood flour content of 70% by weight to 95% by weight, granulated to a particle size of 0.1 mm to 30 mm. Agglomerate grains for wood flour composites, characterized by the following: