JP2002283377A - Woody molded object and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a woody molded object having high strength by a manufacturing method good in heat efficiency and productivity. SOLUTION: As a binder for a woody material W, a thermoplastic resin melt R is sprayed on the woody material W in a mist- or dot-like state to be uniformly dispersed in and mixed with the woody material W. The woody molded object is manufactured by the press molding of a mat comprising a mixture of the wood material W and the thermoplastic resin melt R.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wooden molded product and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, as a method of molding a woody body by mixing a woody material such as wood flour and a thermoplastic resin, a thermoplastic resin is melted by an extruder or a heat melting type kneader, and the like. Methods of extruding or press-molding a mixture in which a wood material is charged and kneaded are proposed.

[0003]

However, when a woody material is put into a thermoplastic resin melted under high temperature and pressure as described above, various sugars and lignins originally contained in the woody material are removed. The components are eluted, and the components are dispersed in the molten thermoplastic resin by the kneading action under high pressure by a screw such as an extruder. As a result, the thermoplastic resin component is deteriorated, and a predetermined hardness or strength cannot be obtained, or the brittleness is not sufficient to obtain sufficient toughness. In some cases, problems such as chalking may occur.

[0004]

According to the present invention, as a means for solving the above-mentioned conventional problems, a thermoplastic resin R in a heated and molten state is sprayed on a heated woody material W in a mist or dot form and mixed. It is intended to provide a wooden molded article obtained by molding the raw material mixture M. The thermoplastic resin R may be manufactured from waste thermoplastic resin. In order to manufacture the above-mentioned woody molded body, a raw material mixture M is prepared by spraying and mixing a heated and molten thermoplastic resin R into a heated woody material W in a mist or dot form with a spray gun, The method of press-forming the raw material mixture M is preferable, and the press-forming of the raw material mixture M is preferably performed by cold pressing.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below.
[Wood material] Examples of the wood material W used in the present invention include wood chips, strands, wood flour, wood wool, wood fiber bundles, wood pulp, ground waste paper, waste paper pulp and the like. The woody material W may be obtained from, for example, scraps and waste materials generated when constructing or dismantling a wooden building. The woody material W of the present invention is particularly preferably a flake-shaped piece of wood. The flake-shaped piece of wood is
For example, in the shape of a thin flake using a ringman, a strander, a shaving machine, or the like manufactured by Pearlman, width 0.5 to 10 mm, length 4 to 70 mm, thickness 0.1 to 0.1
2.5 mm is preferred, especially 4 to 8 mm in width and 20 in length.
A wood piece of about 25 mm and a thickness of 0.5 to 1 mm is desirable. Two or more wood materials W may be mixed. Also, if there is moisture in the wood piece, steam is generated from the wood piece at the time of heat molding, and a water vapor film is formed between the wood piece and the thermoplastic resin, and the adhesion between the wood piece and the thermoplastic resin does not work well. It is desirable that the wood chips are dried to a water content of less than 5% by a dryer after the flakes are processed.

[Thermoplastic resin] As the thermoplastic resin used in the present invention, for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene terpolymer having a melting point of 50 to 300 ° C.,
Ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, polystyrene, polyvinyl acetate, fluororesin, thermoplastic acrylic resin, thermoplastic polyester, thermoplastic polyamide, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer There are thermoplastic resins such as coalesced, acrylonitrile-butadiene-styrene copolymers and waste materials of the thermoplastic resins.

[Utilization of Waste Material] Further, the waste material of the wooden molded article of the present invention is cut, crushed or defibrated into a wooden material W,
Again, it can be reused as a raw material for wood molded products and a raw material for wood cement boards. For example, after the waste material is pulverized to an appropriate size to remove impurities, the pulverized material alone or a small amount of thermoplastic resin waste material is added, and hot pressing is performed to form again. In the recycling of such a wooden molded article, the recyclability is very high, and the recyclability of the thermoplastic resin is greatly improved indirectly. Moreover, such wooden molded bodies are used for building boards, furniture materials,
Because it is used in large quantities in concrete forms and the like, recycled thermoplastic resins can be consumed in large quantities. In addition, the flake-shaped wood chips can be obtained by processing renovated demolition waste wood in a process such as cutting, so that CO ₂ gas generated by incineration of wood can be suppressed, and the environmental load can be reduced. . Particularly useful as the thermoplastic resin of the present invention is a thermoplastic resin sheet for agricultural use in which a large amount of waste material is generated,
Waste materials such as thermoplastic resin bags for packaging, thermoplastic fiber products, home appliance cabinets, and car bumpers.

[Third component] In addition to the above-mentioned woody material W and thermoplastic resin R, the woody molded article of the present invention includes, for example, a water repellent,
An antioxidant such as a waterproofing agent, an antioxidant, and an antioxidant, and a coloring agent may be added. In order to improve nonflammability, inorganic powder such as barium phosphate, aluminum hydroxide, and pulverized ceramic exterior materials may be added.

[Production of Woody Molded Article] To produce the woody molded article of the present invention, first, a thermoplastic resin R in a molten state is sprayed onto a woody material W from a spray gun in a mist or dot form and mixed. The mixing ratio is usually about 30:70 to 90:10 in weight ratio of wood material: thermoplastic resin.

In the mixing process, the thermoplastic resin R in the molten state adheres to the wooden material W in the form of a mist or dots, so that the thermoplastic resin R can be uniformly dispersed in the wooden material W. Even when various kinds of thermoplastic resins R are sprayed simultaneously or sequentially, spraying in the form of mist or dots does not cause phase separation when dispersed in the woody material W regardless of mutual compatibility. In the case of using resin waste material, labor for sorting can be omitted. In order to prepare a mixture of the above-mentioned woody material and a thermoplastic resin, the woody material is generally put into a mixing tank, and the thermoplastic resin melt R is sprayed and mixed with a spray gun while stirring. The mixture is then molded, but press molding is generally applied. In the case of the present invention, since a high-temperature thermoplastic resin melt R is mixed with the wood material, cold press molding can be applied by utilizing the residual heat.

[0011] In the case of mass production, it is preferable to manufacture the woody body continuously. As shown in FIG. 1, a wood material supply conveyor (1)
The upper woody material W is sprayed by spraying rolls (2, 3, 4) disposed on the supply conveyor (1), and the thermoplastic resin melt R is extruded from the extruder (5) to the spray gun (6). The thermoplastic resin melt R is spray-mixed in the form of a mist or a dot from the spray gun (6) and uniformly dispersed in the wood material W. Thus, the thermoplastic resin melt R is spray-mixed in the form of a mist or a dot to form the woody material W.
In this case, the thermoplastic resin melt R can be uniformly dispersed and adhered to the woody material W. Usually, a plurality of spray guns (6) are provided around the wooden material W to be sprayed (for example, 8 spray guns) as shown in FIGS.
) And a plurality of stages (for example, three stages).

After the thermoplastic resin melt R is evenly sprayed on the woody material W, the mixture M
(7) The mixture M deposited on the upper surface in a mat shape is sent to a press (not shown) or a rolling roll press (not shown) to be formed into a plate shape. It is preferable that the entire apparatus before the above-mentioned press or rolling roll press be housed in an atmosphere of heat and heat retention. The ambient temperature is desirably maintained at a temperature at which the discharged thermoplastic resin melt R does not immediately cool and solidify.

If the mixture M of the thermoplastic resin melt R and the woody material W deposited in a mat on the conveyor (7) is press-formed by a pressing device, a roll press or the like immediately after the deposition, the formed body is still in a state. Since heat is stored, cold press molding can be performed, and the obtained molded body is further cooled by a cold press device, a cold roll press, or the like.

[Embodiment 1] In the apparatus shown in FIG.
The internal pressure of the cruster (5) is 5.5 to 10 N / mm ^Two,
The playgun (6) has a nozzle diameter of 1.17 mm and an air pressure of 0.2
The pressure was set to 5 MPa and the air temperature to 240 ° C. Polypropylene
Waste resin waste is pulverized and melted at 230 ° C.
R through the extruder (5) to the spray gun (6)
Weight of wood chips W75 sprayed and dropped from the feeding conveyor (1)
% To 25% by weight in mist from all directions
I attached. The size of the wood W is 4-8mm width, 20-25mm
A long one having a thickness of 0.5 to 1 mm was used.

The homogeneous mixture of the thermoplastic resin melt R and the wood chips W was deposited in a mat on a conveyor (7), and the deposited mixture M was formed in a heat retaining box. At this time, the heating temperature of the wood piece W was set at 105 ° C, and the forming atmosphere temperature was set at 120 to 170 ° C. Thereafter, the mixture M was formed with a cold rolling roll at a pressure of 5 N / mm ² , and then formed while cooling with a cooling roll press to obtain a 12 mm thick woody body.

Example 2 A mixed wood material W mixed at a 9: 1 weight ratio of wood chips and waste paper pulp is put into a mixing tank, and the mixed wood material W is stirred, and polyester resin waste material (PET bottle waste material) Is sufficiently dried and crushed to obtain 28
The resin melt R melted at 0 ° C. is sprayed into a mist by a spray gun, and the resin 30
It was mixed so that it might become the weight%. The mixture was molded using a cold press machine to obtain a 12 mm-thick woody body.

The physical properties of the wood compact are as follows. Example 1 Example 2 absolute dry specific gravity 0.95 0.97 Flexural strength ^{* 1 32.4N / mm 2 31.8N /} mm 2 breaking load ^{* 1 1.46 × 10 3 N 1.43} × 10 3 N Deflection * 1 3.2mm 3.3mm Water absorption * 2 16% 17% Water absorption thickness swelling * 2 8% 9% * 1: According to JIS A 1408 * 2: According to JIS A 5905

Comparative Example As a comparative example, a polypropylene resin waste material was pulverized and a piece of wood (width 4 to 8 mm, length 20)
２５25 mm, thickness 0.5-1 mm) at room temperature, and hot pressing the mixture at a temperature of 200 ° C. under a pressure of 5 N / mm ² ,
Thereafter, cooling was performed to obtain a molded body. The physical properties measured in the same manner as in the examples are as follows.

Comparative Example Absolute dry specific gravity 0.73 Bending strength 18.7 N / mm ² Breaking load 0.84 × 10 ³ N Deflection 4.7 mm Water absorption 78% Water absorption thickness swelling 25%

The bending strength of the comparative example is considerably lower than that of the example. It is considered that this is because the dispersion of the pulverized thermoplastic resin is uneven and there is a portion where no resin component exists between the pieces of wood. Further, the water absorption rate and the water absorption thickness swelling rate are also very poor, and are considered to be due to similar causes.

[0021]

According to the present invention, since the thermoplastic resin in a heat-melted state is sprayed on the wood material in a mist or dot form and dispersed in the wood material, the mixing and dispersion of the thermoplastic resin and the wood material are uniform. And a wooden molded body with high strength is obtained. In addition, it is possible to save heat energy by performing cold press molding using the residual heat of the mixture.

[Brief description of the drawings]

 1 and 2 show one embodiment of the present invention.

FIG. 1 is an explanatory diagram of a mixed state of a wood material and a thermoplastic resin melt.

FIG. 2 is an explanatory view of another embodiment of a mixed state of raw materials.

[Explanation of symbols]

 R thermoplastic resin (thermoplastic resin melt) W wood material (wood piece) M raw material mixture

Continuation of the front page (72) Inventor Misao Okamoto 1-1-88 Oyodonaka, Kita-ku, Osaka-shi, Osaka F-term in Sekisui House Co., Ltd. 2B260 BA02 BA05 BA18 BA19 DA18 EA04 EA11 EB11 4F204 AA11 AA50 AD06 AG02 AH46 FA06 FB01 FB11 FE06 FF01 FF21 FF51

Claims (4)

[Claims] 1. A woody molded article obtained by spraying a thermoplastic resin in a heat-melted state onto a heated woody material in the form of a mist or dots to form a raw material mixture. 2. The wood molded article according to claim 1, wherein said thermoplastic resin is produced from waste thermoplastic resin. 3. A raw material mixture is prepared by spraying and mixing a thermoplastic resin in a heated and molten state into a heated wood material in the form of mist or dots with a spray gun, and press-forming the raw material mixture. PROCESS FOR PRODUCING WOOD MOLDED BODY FEATURED 4. The method according to claim 3, wherein the molding of the raw material mixture is performed by cold press molding utilizing residual heat generated during mixing of the wood material and the thermoplastic resin melt.