JP2003094411A - Woody plate and method for manufacturing woody plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily manufacture a light-weighted woody plate of high strength. SOLUTION: The woody plate 1 comprising a core layer 3 in which wood chips F are linked with thermoplastic woody resin; a front layer 2 in which a woody content is linked with thermoset resin and/or a rear layer, is provided. A raw material mixture for front layer M1 containing a woody content and the thermoset resin is sprayed on a substrate 6 to form a front layer mat 2A. A raw material mixture for core layer M2 of thermoplastic woody resin melt R and the wood chips F are accumulated by feeding on the front layer mat 2A to form a core layer mat 3A. A raw material mixture for rear layer M1 containing the woody content and the thermoset resin is sprayed thereon to form a rear layer mat 4A. The woody plate 1 is manufactured by forming by pressing the three layer mat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wood board used as a building material and a method for manufacturing the wood board.

[0002]

2. Description of the Related Art Conventionally, in this type of wood board, a resin is mixed as a core layer into a wood finely divided material, steam injection pressing is performed to form the core layer, and the core layer is adhered to the front and back surfaces of the core layer. There is provided a laminate of wood molding boards such as plywood, medium density fiber board, and thin particle board according to the agent (Japanese Patent Laid-Open No. 2000-1.
17709).

[0003]

The above wooden board is manufactured by a method in which a core layer is formed once and the wood formed board is adhered to the front and back surfaces of the core layer with an adhesive. A lot of work is required, and an adhesive is also required.

[0004]

[Means for Solving the Problems] As a means for solving the above conventional problems, the present invention binds a core layer (3) formed by binding a piece of wood F with a thermoplastic resin and a wood layer with a thermosetting resin. The present invention provides a wood board (1) consisting of a front layer (2) and / or a back layer (4) which are put on. The wood content of the front and back layers (2,4) is 26 Messi all-through wood flour and / or a thickness of 0.
A wood piece F having a length of 1 to 2 mm, a length of 1 to 30 mm and a width of 0.1 to 5 mm. The wood piece F of the core layer (3) has a thickness of 0.1 to 5 mm and a length of 1
Preferably, the thermoplastic resin is a recycled resin, and the front and back layers are
The wood component (2,4) and / or the wood piece F of the core layer (3) is preferably a recycled product. Further in the present invention, the substrate (6)
The surface layer raw material mixture M ₁ containing a wood component and a thermosetting resin is sprinkled on the surface layer mat (2A) to form a thermoplastic resin melt R and wood chips F on the surface layer mat (2A). Of the core layer raw material mixture M ₂ is supplied and deposited to form the core layer mat (3A), and the back layer raw material mixture M ₁ containing a wood component and a thermosetting resin is sprinkled thereon to form a back layer. Matte (4A)
And a three-layer mat is press-formed to integrate the front and back layers (2, 4) and the core layer (3) into a wooden board.
A manufacturing method of (1) is provided.

[0005]

In the present invention, the core layer (3) has a rough structure by using the wood chips F, but the surface layer (2) and / or the back layer (4) are made by binding the wood components with a thermoplastic resin to form a dense structure. Because of this structure, it is possible to obtain high strength with good dimensional stability even if it is lightweight, and if the thermosetting resin of the front and back layers (2,4) is hardened during hot pressing, the wood board (1) will be completely It can be easily released from the press mold even without cooling, and the wood board (1) has a shape retention property that is easy to handle even if it is not completely cooled. Further, in the present invention, the surface layer raw material mixture M ₁ containing a wood component and a thermosetting resin is sprinkled on the substrate (6) to form the surface layer mat (2A), and the surface layer mat (2A) is heated. A core layer raw material mixture M ₂ of a plastic resin melt R and a piece of wood F is supplied and deposited to form a core layer mat (3A), and a back layer raw material containing a wood component and a thermosetting resin thereon. Since the back layer mat (4A) is formed by spraying the mixture M ₁ and the three-layer mat is press-molded, the front and back layers (2,4) and the core layer (3) are the front and back layers (2,4). ) And the thermoplastic resin melt R of the core layer (3) are bonded and integrated. Therefore, no adhesive is required to bond the core layer (3) to the front and back layers (2,4), and since the thermosetting resin is used only in the front and back layers (2,4), resin decomposition There are few things.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention is described in detail below. [Core Layer] The core layer of the present invention is obtained by binding wood chips with a thermoplastic resin. The above wood pieces are manufactured from wood by cutting with a flaker, and preferably have a thickness of 0.1 to 5 mm, a length of 1 to 50 mm, and a width of 0.5 to 20 mm.
More preferably, the thickness is 0.5 to 1 mm, the length is 20 to 25 mm,
It has a width of 4 to 8 mm. As the wood used as the raw material of the above-mentioned wood pieces, it is preferable to use dismantled wood generated when the building is dismantled, scraps generated when the wood is cut, and the like. By using such recycled products, advanced utilization of wood waste can be achieved.

Examples of the thermoplastic resin for binding the wood chips include polyethylene, polypropylene, ethylene-
Propylene copolymer, ethylene-vinyl acetate copolymer,
Polyvinyl chloride, polyvinylidene chloride, polystyrene,
Polyvinyl acetate, fluororesin, thermoplastic acrylic resin,
Thermoplastic polyester, thermoplastic polyamide, thermoplastic urethane resin, acrylonitrile-butadiene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene copolymer, ethylene-propylene copolymer, ethylene-propylene terpolymer, ethylene -A thermoplastic synthetic resin such as a vinyl acetate copolymer is used. As the thermoplastic resin, it is preferable to use a pulverized product of the waste material of the thermoplastic resin molded product, or a product obtained by melting and pelletizing the pulverized product. By using such a recycled resin, it is possible to highly utilize the resin waste.

[Front and Back Layers] The front and back layers of the present invention are obtained by binding wood components with a thermosetting resin. As the wood component, wood flour and / or wood chips are usually used, and the wood powder preferably has a particle size of 26 mesh, and the wood chips have a smaller size than the wood chips used for the core layer, for example, Thickness 0.1-2mm, length 1-30mm, width 0.1-5m
m, preferably 0.2-0.5 mm thick, 6-12 m long
m, width 0.5-2.5 mm is used. It is preferable to use a recycled product for the above-mentioned wood component as well as the core layer wood piece. The thermosetting resin that binds the wood components,
Phenol resin, melamine resin, urea resin, melamine-
Urea co-condensation resin, resorcinol resin and the like are used.

[Manufacture of Wood Board] In the manufacture of the wood board of the present invention, first, a surface layer raw material mixture in which a wood component and a thermosetting resin are mixed is sprinkled on a substrate to form a surface layer mat, and the surface layer mat is formed. A core layer raw material mixture of a thermoplastic resin melt and wood chips is supplied and deposited on the top to form a core layer mat. In this case, the mixing weight ratio of the wood component and the thermosetting resin in the surface raw material mixture is usually 95/5 to 80 /
20 (wood component / thermosetting resin), the mixing weight ratio of the wood chips and the thermoplastic resin melt in the core layer raw material mixture is
It is usually 80/20 to 60/40 (wood chips / thermoplastic resin). And a back layer raw material mixture similar to the surface layer raw material mixture is sprayed from above to form a back layer mat,
Perform press molding. Press pressure at this time is usually 3 to 10M
It is Pa.

Specifically, for example, the forming apparatus shown in FIG. 1 is used, and the conveying conveyor of the forming apparatus is used.
(5) The raw material mixture M ₁ for the front and back layers is sprinkled on the upper template (6) to form the front mat (2A). This raw material mixture M ₁ is supplied from the raw material transportation path (7) to the spraying device (9A) by the raw material supply conveyor (8A), and from the spraying device (9A) to the template.
(6) Sprinkled on top. Further, the thermoplastic resin melt R is discharged and flown from the orifice (11) of the die (10) arranged above the conveyor (5), and the supply conveyors (12A, 12B) are supplied from both sides.
The wood chips F above are sprinkled by the supply rolls (13, 13) and added into the resin melt R. The piece of wood F is fed from the piece of wood transportation path (14) by the piece of wood supply conveyor (15A, 15B).
Supplied on (12A, 12B). The resin melt R is stretched subdivided resin melt R and wood pieces F and uniformly mixed core layer material mixture M ₂ is obtained, the mixture M ₂ of the core on the surface layer mat (2A) Delivered and deposited as a layer mat (3A).

Next, the raw material mixture M ₁ for the front and back layers is sprinkled on the core mat (3A) to form the back mat (4A). This raw material mixture M ₁ is supplied from the raw material transportation path (7) to the spraying device (9B) by the raw material supply conveyor (8B), and is sprayed from the spraying device (9B) onto the core layer mat (3A). The three-layer structured mat thus formed is hot-pressed by a pressing device. Press temperature is usually 18
Set in the range of 0 ° C to 230 ° C. Thus, FIG.
As shown in Fig. 3, the front and back layers (2, 4) are composed of a thermosetting resin and wood components bound to each other, and the core layer (3) is composed of a wood piece F bonded to a thermoplastic resin melt R. Layered wood board (1)
Is manufactured. In the present invention, a two-layer structure composed of the core layer (3) and the surface layer (2) or the back layer (4) may be used.

[Examples 1 to 4] Hereinafter, Example 1 of the present invention will be described.
~ 4 is shown. As a raw material mixture for the front and back layers, wood flour (26
All the mesh) and the powdered phenolic resin were mixed at a ratio shown in Table 1 and dry-stirred, and a raw material mixture M ₁ for the front and back layers was used. As the wood piece F for the raw material for the core layer, demolition wood is crushed and fragmented with a flaker, etc., and has an average thickness of 0.5 to 1 mm and a length of 2
Wood pieces having a width of 0 to 25 mm and a width of 4 to 8 mm were used, and waste polypropylene was used as a thermoplastic resin to pelletize and use a pulverized product.

[0013]

[Table 1]

Using these raw materials, the forming apparatus shown in FIG. 1 was used to first mix wood powder and powdered phenolic resin on the front and back of a template (6) moving on a conveyor (5). The raw material mixture M ₁ for layers was sprayed to obtain a surface mat (2A). On top of that, a waste crushed product of polypropylene molding, which is a raw material for the core layer, is melted at 200 to 240 ° C. to form a die (10).
Melted and discharged from the orifice (11) of the above, and the wood pieces F were sprinkled from both sides, and the polypropylene melt R was mixed while being drawn and thinned. The core layer raw material mixture M ₂ (wood pieces F: polypropylene melt R = 7: 3) was deposited and the core mat (3A) was loaded. Further, the raw material mixture M ₁ for the front and back layers was sprinkled thereon and the back layer mat (4A) was loaded to obtain a three-layered laminated mat. After that, hot press is applied (press pressure 3 to 10MP.
a), molded wood board.

Examples 5 to 6 As raw materials for the front and back layers,
Wood pieces in place of wood flour (thickness 0.2-0.5 mm, length 6-12)
mm, width 0.5 to 2.5 mm)
The same procedure as in ~ 4 was performed.

Comparative Examples 1 to 4 Comparative Examples 1 and 2 are core layer raw material mixture M ₂ (wood piece F: polypropylene melt R = 7:
3) A wood board having a thickness of 12 mm obtained by molding only a single-layer mat, Comparative Example 3 uses a mixture of the raw materials M ₁ for the front and back layers to which the polypropylene melt R is added, and the core layer is the same as that of each example. A wood board molded using the same raw material mixture M ₂ , and Comparative Example 4 is a wood board in which the resin of the front and back layers is 5% or less (1.5%). Table 2 shows the results of measuring various physical properties of the wooden boards obtained in Examples 1 to 6 and Comparative Examples 1 to 4.

[0017]

[Table 2]

According to Table 2, Example 1 having almost the same specific gravity,
2, 5, 6 and Comparative Example 1, and Examples 3, 4 and Comparative Example 2
When compared with, the strength of each example is improved by 20 to 30%, and the dimensional stability in each example is significantly improved from the data of water absorption elongation rate and moisture release shrinkage rate. I understand. Further, in Comparative Example 3 in which polypropylene, which is a thermoplastic resin, is used as the resin for the front and back layers, the water absorption elongation rate and the moisture release shrinkage rate are higher than those of the examples, and the phenol resin for the front and back layers is 5% or less at 1.5%. The bending strength of the added Comparative Example 4 is smaller than that of the example.

[0019]

According to the present invention, a high-strength and light-weight wooden board having a small dimensional change due to absorption of water and moisture can be easily manufactured in almost one shot.

[Brief description of drawings]

1 and 2 show an embodiment of the present invention.

FIG. 1 is an explanatory diagram of a forming device

[Fig. 2] Side view of a wooden board

[Explanation of symbols]

1 Wood board 2 Surface layer 2A Surface layer mat 3 Core layer 3A Core layer mat 4 Back layer 4A Back layer mat 6 Substrate (template) F Wood piece R Thermoplastic resin melt M ₁ Raw material mixture for front and back layers M ₂ Raw material mixture for core layer

Claims (5)

[Claims] 1. A wood board comprising a core layer formed by binding wood pieces with a thermoplastic resin, and a surface layer and / or back layer formed by binding wood components with a thermosetting resin. 2. The wood component of the front and back layers is wood powder of 26 Messi and / or wood chips having a thickness of 0.1 to 2 mm, a length of 1 to 30 mm, and a width of 0.1 to 5 mm. The wood piece is 0.1 thick
The wood board according to claim 1, which has a length of -5 mm, a length of 1-50 mm, and a width of 0.5-20 mm. 3. The thermoplastic resin is a recycled resin.
Or the wood board described in 2. 4. The wood board according to claim 1, wherein the wood component of the front and back layers and / or the wood piece of the core layer is a recycled product. 5. A surface layer mat is formed by spraying a surface layer raw material mixture containing a wood component and a thermosetting resin on a substrate to form a surface layer mat, and for the core layer of a thermoplastic resin melt and wood chips on the surface layer mat. A raw material mixture is supplied and deposited to form a core layer mat, and a back layer raw material mixture containing a wood component and a thermosetting resin is sprinkled on the core layer mat to form a back layer mat, and the three-layer mat is pressed. The method for manufacturing a wood board according to any one of claims 1 to 4, wherein the front and back layers and the core layer are integrated by molding.