JP2003305707A - Wooden composite material and method for manufacturing it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a wooden composite material which can be enough used as a structural material even when length of a piece of a wooden material is at most 150 mm. <P>SOLUTION: Slender pieces of a wooden material in which at least 70% of the weight ratio has a specific gravity of 0.3-0.6 and a length in a range of 20-150 mm and a binder are used as the materials. The pieces of the wooden material are piled up under a condition where they are oriented so as to face approximately one direction and are bound together by being heated and pressed to make the specific gravity at least 0.6. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a wood-based composite material and a method for producing the same.

[0002]

2. Description of the Related Art A wood-based composite material called engineering wood used as a structural material has hitherto been known as a wood material piece with a binder, which is carried by, for example, applying a binder to an elongated wood material piece. It is obtained by stacking in the same direction in the longitudinal direction and pressurizing and heating the laminated body (for example, Patent Document 1). Further, it is also known that a wood-based composite material, which is to be obtained as a wood material piece, is laminated in a mat shape in a state of being oriented in the length direction and the mat is pressed and heated (for example, Patent Document 2). ).

In the wood-based composite material produced in this manner, it is necessary to use elongated wood material pieces having a certain length or more in the fiber direction in order to obtain the strength required as a structural material. The technique described uses a piece of wood material having a fiber direction length of 15 cm or more.
That is, the short wooden material pieces cannot be used because the strength of the obtained composite material cannot be secured.

[0004]

[Patent Document 1] Japanese Patent Publication No. 50-17512

[0005]

[Patent Document 2] Japanese Patent No. 2527761

[0006]

However, according to the study by the present inventor, the wood waste, which has become a problem in recent years, becomes a raw material for the wood-based composite material used in the conventional method. Obtaining long pieces of wood material is becoming difficult. That is, wood waste includes scrap materials generated at factories and residential construction sites, waste pallet materials discarded after transportation of members, dismantled waste materials generated during building dismantling, etc. In addition, since foreign matter is mixed in, the blade for cutting is easily damaged, and stable operation is difficult. On the other hand, when a crusher having a high resistance to the above foreign substances is used, the length of the obtained wood material piece is about 2 cm to 10 cm, so that the conventional manufacturing method that requires a wood material piece having a fiber direction of 15 cm or more. Can not be used in the method.

The object of the present invention is, in view of the above-mentioned problems in the conventional method for manufacturing a wood-based composite material, for example, even when a short wood material piece of less than 150 mm is used, it can be sufficiently used as a structural material. It is to provide a high-strength wood-based composite material.

[0008]

In order to achieve the above object, the wood-based composite material according to claim 1 of the present invention (hereinafter, referred to as
The "composite material of claim 1" refers to a material containing elongated wood material pieces having a specific gravity of 0.3 to 0.6 and a length of 20 mm to 150 mm in a weight ratio of 70% or more, and a binder. When the wood material pieces are stacked in a state in which they are oriented so as to face almost one direction, they are heated and pressed to bond the wood material pieces to each other with a binder, and their specific gravity is 0.6 or more. It has a feature. The wood-based composite material according to claim 2 of the present invention (hereinafter referred to as “composite material of claim 2”) is
70% or more of the weight ratio is made of a material containing an elongated wood material piece having a length in the range of 20 mm to 150 mm and a binder, and the wood material pieces are stacked in a state of being oriented so as to face substantially one direction. The material pieces are flattened in a direction perpendicular to the longitudinal direction, the cross-sectional area of the wood material pieces is compressed to 70% or less on average, and the wood material pieces are bonded together by a binder.

A method for manufacturing a wood-based composite material according to claim 3 of the present invention (hereinafter, referred to as "method for manufacturing a composite material according to claim 3").
) Is a process of crushing wood with a crusher, and a crushed wood material piece having a weight ratio of 70% or more has a length of 20 mm to 15 mm.
Classifying to a range of 0 mm, mixing the crushed wood material pieces with a binder, orienting and stacking the wood material pieces so as to face almost one direction, and steaming with 0.5 to 2 Pa of steam. It is characterized by comprising a step of heating and a step of applying pressure from a direction perpendicular to the longitudinal direction of the wood material piece.

In the present invention, the thickness of the wood material piece means
Of the dimensions of the axial wood material pieces in two directions orthogonal to the longitudinal axis of the wood material piece and orthogonal to each other, the shorter dimension was defined as the thickness.

[0011] As the raw material tree species that become the wood material pieces,
Mainly coniferous trees such as cedar, cypress, spruce, fir and radiata pine, and broad-leaved trees such as birch, apiton, chamelele, sengonlaut and aspen are mentioned. It can also include plant material produced outside the forest. The form that can be used as a raw material is not particularly limited, but includes, for example, logs of the above tree species, raw materials such as thinned wood, mill ends generated at factories and residential construction sites, waste pallet materials discarded after transporting members, construction Examples include dismantling waste materials generated during dismantling.

As a method of processing the above-mentioned raw material into a wood-based material piece, a veneer-processed one using a rotary cutter is cut into a chopstick shape into a stick, or a log is cut into a strand by a rotary blade of a flaker. A method of crushing wood by rotating a roll having a knife on the surface of a uniaxial crusher can be used. The crusher also includes a machine generally called a crusher. In addition, it is possible to use a small piece manufacturing machine that uses cutting, which is generally used for particle boards, but the small pieces are thinly cut and the strength is relatively difficult, so crushing with crushing as an element The crushed chips produced by the machine are spindle-shaped and easily have high strength, and this is more preferable.

When the wood material pieces crushed as described above are not uniform in thickness, they are classified into wood material pieces having a certain range of thickness. The method is not particularly limited as long as it can be classified, and examples thereof include a method of classifying using a classifier such as a wave roller system. The wave roller type classifier is an apparatus that classifies continuously based on the chip thickness.

The wood-based composite material used in the wood-based composite material of the present invention has a specific gravity of 0.3 to 0.6, a length of 20 mm to 150 mm, and a thickness (short side) of 1 mm. It is preferably ˜11 mm. The bulk density of the produced wood-based composite material is limited to 0.6 or more, and the reason is as follows. That is, when the specific gravity of the wood material piece is less than 0.3, sufficient strength cannot be obtained because the wood material has rotted, or the consolidation treatment at the time of molding cannot be sufficiently performed, and the strength is obtained. Absent. If the specific gravity of the wood material piece exceeds 0.6, the wood material piece is hard and it is difficult to mold it as a desired structural material.

If a wood material piece having a thickness of less than 1 mm is used, the constituent material piece becomes too small, a large amount of binder is required, and strength is not exhibited. On the other hand, when the thickness of the wood material piece exceeds 11 mm, the number of laminated wood material pieces in the thickness direction of the structural material is reduced, stress transmission cannot be sufficiently performed, and stress concentration occurs at the joint of the wood material pieces. It is easy to obtain desired strength. 20 pieces of wood material
If it is less than mm, the strength in the axial direction becomes insufficient when it is used as a structural material, and if it exceeds 150 mm, when the wood material pieces are laminated, the lamination intersection of one wood material piece is It will increase and it cannot be fully consolidated. Since the length of the wood material piece is not a material that can be completely separated, the weight ratio is 70% or more, and preferably 80% or more, if the crushed chips having the above length are contained, a sufficient effect is obtained. To be demonstrated.

The ratio of the length and the thickness of the wood material piece is
Although not particularly limited, the length is preferably 10 times or more the thickness. That is, if the length is less than 10 times the thickness, the strength of the wood-based composite material in the axial direction may be insufficient.

When the bulk density is less than 0.6, the wood material pieces cannot be sufficiently bonded, and when used as a structural material, sufficient strength may not be obtained. Furthermore, the porosity is not particularly limited, but is preferably 10% or less. That is, if the porosity exceeds 10%, the wooden material pieces in the wooden composite material may not be sufficiently bonded to each other, and sufficient strength may not be exhibited.

Further, it is preferable that the wood material piece has a constant water content. By keeping the water content constant, there is no variation in quality of the wood-based composite material during production. The preferable water content is 0 to 10%. As a method of keeping the water content constant, for example, there is a method of allowing the wood material piece to stand for a certain period of time in a temperature-controlled oven. By the way, 50 ℃
When left in the oven for 24 hours, the water content is kept at about 5%.

Examples of the binder used in the present invention include phenol resin, urea resin, isocyanate, and other adhesives for the wood industry used for plywood and particle boards. These binders may be used alone or in combination of several kinds. You may. Further, the binder may be liquid or powder, but in the case of a liquid, it is generally sprayed on the wood material piece or agitated and mixed with the wood material piece and supplied to the forming mold while being carried on the wood material piece in advance. In the case of powder, it is generally supplied to the forming mold in a state of being uniformly mixed with the wood material pieces.

As a method for introducing the binder-bonded wood material pieces obtained as described above into a forming mold, a method for manufacturing an existing wood-based molding material such as an oriented strand board (OSB) is used. A known orienting means such as a disc orienter may be arranged above the forming die, and a method of pouring may be used while orienting by this orienting means. Place a hopper with an inner surface (beak-shaped) orientation part whose width decreases toward the discharge port above the forming mold so that the discharge port faces the upper opening of each split frame, and insert through the hopper. It is preferable to use the method. In addition, it is possible to use a method of arranging the gutters in parallel in the width direction so as to form concave and convex grooves, and arranging them by flowing through the grooves.

That is, by using the above hopper, it is possible to efficiently form each of the forming type dividing frame parts,
That is, it becomes possible to supply the wood material piece with the binder without loss. The shape of the inner surface of the hopper is determined by the shape of the forming type, but any shape may be used as long as the wood material piece with the binder is not clogged. Specifically, it is preferable that the slit width of the discharge port is 15 mm or more and smaller than the inner width of the divided frame portion.

The shape of the forming type is appropriately determined depending on the wood-based composite material to be obtained.
When obtaining a plate-shaped wood-based composite material of 00 × 500 × 30 mm, 1000 × 500 × 1 is formed by the forming type.
Laminate mats of the order of 00 mm must be made. That is, the vertical and horizontal dimensions of the laminated mat are the same as the vertical and horizontal dimensions of the wood-based composite material to be obtained, or are made slightly larger, and the thickness of the laminated mat is at least the thickness of the wood-based composite material to be obtained. The thickness is preferably three times or more the thickness of the composite material.

The method of forming the dividing frame portions at regular intervals in the forming type is not particularly specified, but it is the same as the length and width of the wood-based composite material to be obtained, or slightly larger. A few meters thick inside the frame-shaped mold body
It suffices to partition with a metal plate of m. The direction of division depends on the required molded product because the strength characteristics differ between the direction in which the wood material pieces are oriented and the direction perpendicular to the orientation. By the way, 1000 × 500 × 30mm as above
If you want to obtain a plate-shaped wood-based composite material,
It is preferable to use a forming die in which the inside of a forming die main body having a frame shape of 500 × 100 mm is divided by 19 partition plates having a height of 100 mm at a constant interval of 20 mm in the width direction (500 mm side). Further, the partition plate may be fixed to the forming type main body or may be detachable.

Further, there is a more preferable relationship between the thickness of the wood material piece and the inner width of the dividing frame in order to obtain a high-strength wood-based composite material. For example, the thickness of the wood material piece is 1 mm to
When the thickness is 11 mm, the inner width of the forming-type dividing frame portion is preferably 20 mm to 40 mm, and when the thickness of the wood material piece is 3 mm to 5 mm, the inner width of the forming-type dividing frame portion is 20 mm to It is preferably 30 mm.

If the inner width of the dividing frame portion is too narrow, the wood material pieces will not fall cleanly into the dividing frame portion, which is likely to cause troubles in automatic production. If the inner width of the dividing frame portion is too wide, the wooden material pieces will be May become difficult to align, and the required strength in the alignment direction may not be obtained. A mat made of wood material oriented in the forming mold is put into a press machine that can pressurize and heat with the entire forming mold removed or with only the partition plate that is the partition wall leaving the forming mold body. It is pressed, but if the laminated state of the wood material pieces collapses when the partition plate or forming mold is removed, it is possible to place a collapse prevention sheet on the forming mold in advance and press-mold the sheet together. Is. That is, for example, newspaper may be laid in the forming mold as the collapse prevention sheet, and when the forming mold is removed, the mat may be wrapped with the newspaper and press-molded with the string or adhesive tape fixed.

The press machine is not particularly limited,
For example, it is possible to use a vertical press machine for molding an existing wood-based material or a continuous press machine operated in a vertical direction. The temperature condition of the press is usually preferably in the range of 100 to 250 ° C. The temperature condition of the press is usually 100 to 2
The range of 50 ° C is preferred. The pressure condition is preferably in the range of 1 to 10 MPa. The pressing time may be the time for the binder to harden. If it is less than 1 MPa, it cannot be compressed sufficiently, and if it is 10 MPa or more, the equipment for pressing becomes expensive. The pressing time may be heating and pressure for hardening the binder.

The heating method is not particularly limited,
For example, a method of transferring heat from the surface of the wood material piece to the inside by heat transfer such as a heating plate, or a method of directly heating the inside such as steam injection or high frequency heating can be mentioned. The heating and the pressing may be performed at the same time, the heating may be performed after the pressing, or the heating and the pressing may be performed. When heating with steam, steam is injected at a pressure of 0.5 to 2 Pa.
This is because when it is 0.5 or less, the wood material piece is not softened and cannot be compressed, and when it is 2 Pa or more, the equipment becomes too large, which is not realistic. Further, in the present invention, it is preferable that the laminated mat of the wood material pieces has three or more layers. That is,
If the number of layers is two or less, sufficient strength as a structural material may not be obtained.

Further, when the wood-based composite material of the present invention is produced, after the press molding, in order to improve the dimensional accuracy and surface property of the obtained wood-based composite material, annealing treatment, cutting, and sanding are performed. Is preferred.

[0029]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. 1 and 2 show a first example of a method for manufacturing a wood-based composite material according to the present invention.

In this manufacturing method, first, as shown in FIG. 1 (a), a wood-based crushed chip obtained by crushing or cutting raw material wood such as waste wood with a crusher or a cutting machine (not shown). 1
a is classified with a wave roller type classifier 2 to a thickness of 1
mm to 11 mm, length 20 mm to 150 mm, length / thickness ≧ 10, specific gravity 0.3 to 0.6, a wood material piece 1b is obtained. Next, as shown in FIG. 1 (b), the wood material piece 1b
Was placed in a dryer 3 and dried to a water content of 0 to 10%, and then, as shown in FIG.
, The binder 5 is spray-dispersed on the wood material pieces 1b in the drum blender 4, and the wood material pieces 1b are loaded with the binder 5 in the drum blender 4 so that the wood material pieces with the binder 1
get c.

Then, as shown in FIG. 2, after the forming die 7 divided into a plurality of dividing frame portions 72 by the partition wall 71 to be obtained is set on the receiver 61 of the conveyor 6, the orienting means by the conveyor 6 is set. The forming die 7 is moved below the disc orienter 73 as shown in FIG. When the forming die 7 moves to a predetermined position below the disc orienter 73, the binder-attached wood material piece 1c is supplied to the disc orienter 73 from above, and the fiber direction of the wood material piece 1b is divided by the disc orienter 73. The wood material piece 1c with a binder is put into each of the divided frame portions 72 while being oriented so as to face the longitudinal direction of the portion 72. In addition, at this time, the forming die 7 is moved in the conveying direction of the conveyor 6 (direction of arrow B in FIG. 2) so that the wood material piece with binder 1c can be uniformly introduced in the longitudinal direction of the dividing frame portion 72.
Move back and forth.

Then, after the wood material piece 1c with the binder is laminated to a predetermined height of the forming die 7, the forming die 7 is pulled up and removed, and the laminated mat 1d on which the wood material piece 1b is laminated is conveyed by the conveyor 6. The laminated mat 1d is moved to the press machine 8 and is heated by the press machine 8, and the porosity of 10% or less and the bulk density of 0.6 or more to be obtained from the laminating direction of the wood material piece 1b, that is, the vertical direction. It is press-formed into a wood-based composite material.

Thereafter, if necessary, annealing, cutting and sanding are performed to obtain a wood-based composite material 1e.

The wood-based composite material of the present invention thus obtained uses the wood material piece 1b having a thickness of 1 mm to 11 mm, a length of 20 mm to 150 mm, and a length / thickness of ≧ 10 as described above. Manufactured with a porosity of 10% or less and a bulk density of 0.
Since it is 6 or more, it has sufficient strength as a structural material.

The wood material piece is flattened in the direction perpendicular to the longitudinal direction and the cross-sectional area of the wood material piece is compressed to 70% or less. FIG. 5 is a cross-sectional view of a wood-based composite material, (a) shows a state before being put in a U-shaped guide and is pressed, and (b) is molded after being pressed. It represents the state. When the wood material pieces are simply stacked by orienting them in the longitudinal direction, voids are generated between the chips and the strength is low.
However, the stack of chips that are flattened in the direction perpendicular to the longitudinal direction changes from spindle-shaped to flat-shaped,
The voids between the chips are physically small and the strength is high. When the cross-sectional area is 70% or more, the shape of the cross section of the chip becomes close to a spindle shape, and even if the chips are oriented in one direction, there is a problem that a gap is formed between chips and the physical properties are deteriorated.

As shown in FIG. 6, this wood-based composite material 1
Is formed by laminating the elongated wood material pieces 1b so that the wood material pieces are oriented in the longitudinal direction thereof, and by heat-press molding with a binder interposed therebetween. Has a fiber direction dimension of 2 cm or more and less than 15 cm and the fiber direction α of each wood material piece 1b and the wood-based composite material 1
The average of the absolute values of the angle with the longitudinal direction (direction of arrow X in FIG. 1) is within 30 degrees.

As a method of measuring the orientation angle, an image of the wood-based raw material piece of this wood-based laminated mat is taken by a digital still camera and loaded into a computer. This image data is used in a paint shop (trade name: (Jusk Software Co., Ltd., ver. 6) to extract the shape from the color value and the brightness value of the wood-based raw material piece).

Next, this image is taken from Photoshop (product name,
Adobe Systems, ver. The cut-out process is performed in 5), and the orientation angle and the dimension are measured by the determination program (self-developed elliptical model software). The same operation is repeated several times to statistically measure the orientation angle distribution and the size distribution. The measured experimental value of the orientation angle is that the length of the wood material piece is 5 mm.
The average orientation angle of the above materials was 14 °, and the average orientation angle of the materials having a length of 20 mm or more was 12.7 °.

The thickness is 1 mm to 11 mm and the length is 20.
When using a crusher of mm to 150 mm which cannot be used conventionally, the length of the obtained wood material piece is 2 cm to
It becomes possible to use wood material pieces that are about 10 cm shorter,
It becomes possible to effectively recycle waste materials.

In the manufacturing method of the wood-based composite material 1e, the wood material piece 1c with the binder is oriented and supplied to the forming die 7, but the inside of the forming die 7 is divided into the divided frame portions 72. Since the wood material piece 1c with a binder supplied into the forming die 7 is regulated by the partition wall 71 of the dividing frame portion 72, the wood material piece 1c has a short fiber length and a random length. However, it is possible to orient extremely uniformly and at the same time, and the dividing frame portion 7
In the state of being oriented in the longitudinal direction of No. 2, it is surely laminated in a mat shape without losing its shape.

Since the wood material piece 1b with the binder is pressed in the stacking direction, the manufacturing method can be simplified and the manufacturing cost can be reduced.

FIGS. 3 and 4 show another example of the method for producing a wood-based composite material according to the present invention. As shown in FIG. 3 and FIG. 4, in this manufacturing method, instead of the disc orienter 73, the wood material piece 1b with a binder is supplied to the forming die 7 via a hopper 9, as described in detail below. The manufacturing method is the same as the manufacturing method described above except that this is done.

That is, in this manufacturing method, the hopper 9 has an upper inlet 91 and a slit-shaped outlet 92 in the lower portion, and has an inner surface shape whose width decreases from the inlet 91 to the outlet 92. At the same time, it can be horizontally moved to a supplementary training orthogonal to the traveling direction of the conveyor 6. Then, when the forming die 7 is moved below the hopper 9 by the conveyor 6, the hopper 9 is discharged from above from the dividing frame portion 72 whose discharge port 92 is located at one end in the width direction of the forming die 7. The wood material piece 1b with a binder is placed in the facing position, and the wood material piece 1b with a binder is supplied into the split frame portion 72 via the hopper 9, and a necessary amount of the wood material piece 1b with a binder is supplied into one split frame portion 72. Then, the hopper 9 is slid horizontally to the upper side of the adjacent dividing frame parts 72 to perform the same supply, and the necessary amount of the wood material piece 1b with the binder is supplied into all the dividing frame parts 72. Has become.

Further, according to this manufacturing method, in addition to the effect of the above-described manufacturing method, the hopper 9 can reliably supply the wood material piece 1b with the binder without loss of each divided frame portion, so that it is more precise. It is possible to obtain a wood-based composite material excellent in strength.

The wood-based composite material according to the present invention is not limited to the above embodiment. For example, in the above-described embodiment, the wood material pieces with the binder are sequentially supplied to the split frame portion by one hopper, but a plurality of hoppers can be arranged in the width direction and simultaneously supplied to the plurality of split frame portions. You may do so. Further, in the above-mentioned embodiment, after the wood material pieces with the binder are laminated to a predetermined height of the forming mold, the forming mold is removed by pulling it upward, but the partition plate serving as a partition wall is arranged upward. The forming type main body may be pulled up and disassembled and removed.

[0046]

Example 1 A wood-based composite material was produced by the process shown in FIG. Specifically, the chips for boards purchased from a wood waste disposal company are classified using a wave roller screen classifier Wave roller screen (manufactured by Taihei Co., Ltd.) to obtain a thickness of 1 mm to 11 mm and a length of 20.
mm-150 mm, length / thickness = 10 or more, specific gravity 0.3
~ 0.6 wood material pieces were obtained.

The specific gravity of the wood material pieces was extracted and inspected, and the length was confirmed by image measurement. The water content of the above wood material pieces was adjusted with a heating oven (50 ° C., 24 h) (water content was 5.2%).

Next, a wood material piece with a binder, in which 5% by weight of an isocyanate-based adhesive was applied to a wood material piece, was prepared by adding a wood material piece having a water content adjusted to a drum blender and an isocyanate-based adhesive as a binder. Got a piece. Next, the obtained wood material piece with a binder was put into an OSL forming machine (manufactured by Taihei Co., Ltd.) and put into a forming mold by the method shown in FIG. The forming type has a vertical length of 2
000 mm, width 500 mm, height 100 mm, metal partition plate with internal partition wall (iron, thickness 2 m
m) was used, which was provided with a dividing frame part divided into 10 equal parts at 50 mm intervals.

Next, the forming mat was demolded as shown in FIG. 2 to obtain a laminated mat, and the mold had a length of 2500 mm and a width of 50 mm.
It is put into a heat transfer type press machine (Kawasaki Yuko Co., Ltd. 300t press) having a height of 0 mm and a height of 150 mm, and a heating temperature of 1
At 80 ° C., a pressure of 30 kg / cm 2, and a pressing time of 10 minutes, the press board was kept under pressure while the final shape was 2000 × 500 × 30 mm to obtain a wood-based composite material. Next, all 6 surfaces of the obtained wood-based composite material were cut to obtain a plate-like body of 1500 * 400 * 25 mm wood-based composite material.

(Example 2) 15 was carried out in the same manner as in Example 1 except that the powdery phenolic resin and the woody material piece were mixed in a Henschel mixer, and were manually put into a forming die.
A plate-like body of a wood-based composite material having a size of 00 × 400 × 25 mm was obtained.

(Example 3) A laminated mat obtained by laminating two pieces of wood material with a binder in a forming mold was heated and compressed under the same working conditions as in Example 1 to obtain a final shape of 2000.
A wood composite material of × 500 × 12.5 mm was obtained. Next, cut all 6 sides of the obtained wood-based composite material,
A plate-like body of a wood-based composite material having a size of 0 × 400 × 10 mm was obtained.

(Comparative Example 1) 1500 × 400 × 25 mm in the same manner as in Example 1 except that a wood material piece having a thickness of 1 mm or less was used and 20% by weight of a binder was applied.
A plate-like body of wood-based composite material was obtained.

Comparative Example 2 1500 × 400 in the same manner as in Example 1 except that a wood material piece having a thickness of 1 mm to 11 mm, a length of 5 mm to 55 mm, and a length / thickness = average of 5 was used.
A plate-like body of wood composite material having a size of 25 mm was obtained.

(Comparative Example 3) The final shape is 2000 × 500.
1 was carried out in the same manner as in Example 2 except that the wood-based composite material was obtained by keeping the press platen while applying a pressure of 40 mm.
A plate-like body of a wood-based composite material having a size of 500 × 400 × 25 mm was obtained.

The porosity, bulk density (apparent specific gravity), bending strength and elastic modulus of the plate-like bodies obtained in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated, and the results are shown in Table 1. . The bulk density, bending strength and elastic modulus were measured according to JIS Z 2101. For the porosity, copy the cross section of the molded sample with a copier, measure the paper weight at the cross section (A) Cut the gap between the chips / chips, and measure the weight (B) Porosity ( %) = (B) / (A) × 100.
Different cross sections were measured at least 5 times, and the average value was taken as the porosity.

[0056]

[Table 1]

From the above Table 1, the wood-based composite material of the present invention is
It can be seen that even if a short piece of wood material is used as a raw material, it can be used as a structural material with high strength.

[0058]

Since the wood-based composite material according to the present invention is configured as described above, it can be used as a structural material that exhibits sufficient strength even if a short wood material piece obtained by crushing waste wood or the like is used. Become. Therefore, it is possible to effectively use the waste material that has been conventionally discarded, reduce the cost of processing the waste material, and prevent environmental pollution due to incineration of the waste material.

[Brief description of drawings]

FIG. 1 is an explanatory view illustrating an example of a method for manufacturing a wood-based composite material according to the present invention, and illustrating a manufacturing process of a wood-based material piece with a binder.

FIG. 2 is an explanatory diagram showing the steps subsequent to that of FIG. 1 in the order of steps.

FIG. 3 is another example of the method for manufacturing a wood-based composite material according to the present invention, which is an explanatory view illustrating the manufacturing process thereof.

FIG. 4 is an explanatory view for explaining supplying the woody material pieces to the forming mold through the hopper.

5A and 5B are cross-sectional views of a wood-based composite material according to the present invention, where FIG. 5A shows a state before pressurization and FIG. 5B shows a state after pressurization.

FIG. 6 is an explanatory view showing the upper surface of the wood-based composite material according to the present invention.

[Explanation of symbols]

1b Wood material pieces 1c Piece of wood material with binder 1d laminated mat 5 binder

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[Procedure amendment]

[Submission date] June 4, 2003 (2003.6.4)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

A method for manufacturing a wood-based composite material according to claim 3 of the present invention (hereinafter, referred to as "method for manufacturing a composite material according to claim 3").
) Is a process of crushing wood with a crusher, and a crushed wood material piece having a weight ratio of 70% or more has a length of 20 mm to 15 mm.
A step of classifying into a range of 0 mm, a step of mixing a crushed wood material piece with a binder, a step of orienting and stacking the wood material piece so as to face almost one direction, a step of heating with steam , and a wood material Pressurizing from a direction perpendicular to the longitudinal direction of the material piece.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

The press machine is not particularly limited,
For example, it is possible to use a vertical press machine for molding an existing wood-based material or a continuous press machine operated in a vertical direction. Temperature conditions of the press machine, not preferred in the range of usually 100~250 ℃. The pressure condition is preferably in the range of 1 to 10 MPa. The pressing time may be the time for the binder to harden. If it is less than 1 MPa, it cannot be compressed sufficiently and it is 10 MPa.
If it is above, the equipment for presses will become expensive. The pressing time may be heating and pressure for hardening the binder.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

The heating method is not particularly limited,
For example, a method of transferring heat from the surface of the wood material piece to the inside by heat transfer such as a heating plate, or a method of directly heating the inside such as steam injection or high frequency heating can be mentioned. The heating and the pressing may be performed at the same time, the heating may be performed after the pressing, or the heating and the pressing may be performed. When heating with steam, steam is injected at a pressure of 0.5 to 2 MPa .
This is because when the pressure is 0.5 MPa or less, the wood material piece cannot be compressed without being softened, and when the pressure is 2 MPa or more, the equipment becomes too large to be realistic. Further, in the present invention, it is preferable that the laminated mat of the wood material pieces has three or more layers.
That is, if the number of layers is two or less, sufficient strength as a structural material may not be obtained.

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Claims (3)

[Claims] 1. A weight ratio of 70% or more has a specific gravity of 0.3 to 0.6,
It is made of a material containing an elongated wood material piece having a length in the range of 20 mm to 150 mm and a binder, and the wood material piece is stacked in a state of being oriented so as to face substantially one direction, and heated and pressed. The wood material pieces are joined together by the binder,
A wood-based composite material having a specific gravity of 0.6 or more. 2. A weight ratio of 70% or more has a length of 20 mm to 150.
made of a material containing an elongated wood material piece in the range of mm and a binder, the wood material pieces are stacked in a state in which they are oriented so as to face substantially one direction, and the wood material piece is perpendicular to the longitudinal direction. The average cross-sectional area of wood material pieces is 70%
A wood-based composite material, characterized in that it is compressed below and the wood material pieces are bonded together by a binder. 3. A step of crushing wood with a crusher, and a crushed wood material piece having a weight ratio of 70% or more having a length of 20 mm to 15
0.5 to 2 Pa, a step of classifying to a range of 0 mm, a step of mixing a crushed wood material piece with a binder, a step of orienting and stacking the wood material piece so as to face almost one direction. And a step of pressurizing from the direction perpendicular to the longitudinal direction of the wood material piece, the method for manufacturing a wood-based composite material.