JPH07137009A - Manufacture of lignified plate - Google Patents

Abstract

PURPOSE:To provide a method for manufacturing a lignified plate which can be manufactured by efficiently utilizing wood thin pieces and which has a light weight, a smooth surface, sufficient strength and rigidity and in which surface smoothness is not lowered even at a high temperature and high humidity environment. CONSTITUTION:The method for manufacturing a lignified plate comprises the sorting step 12 of sorting from many wood thin pieces, before forming steps 20, 21, 22, small-sized wood thin pieces of a size distribution of a length of 50-75mm and a width of 6-50mm and large-sized wood thin pieces of a size distribution of a length of 50-100m and a width of 6-100m, and dividing the steps 20, 21, 22 into a plurality of steps. The large-sized wood thin pieces and the small-sized wood thin pieces are deposited once or more to form aggregates, which are hot-press solidified to manufacture the plate having a core material made of the small-sized thin pieces and a surface layer material made of the large-sized thin pieces.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a wooden board, and more particularly to a method for producing a wooden board which is constructed by depositing wood flakes, has a smooth surface, is lightweight, and has sufficient strength and rigidity. .

[0002]

2. Description of the Related Art In recent years, shortage of wood resources and protection of forests have become problems, and it is clear that deforestation will become more difficult in the future. Therefore, it is expected that supply of plate materials such as plywood manufactured by using a large amount of raw wood will be unstable or insufficient, and the price will also rise. Therefore, wood flakes, which have been conventionally scrapped, and wood boards obtained by effectively using wood fibers of wood flakes have attracted attention, and application of the wood boards to various uses is strongly desired. A wood board using wood flakes or wood fibers is generally formed by adhering constituent elements such as wood flakes or wood fibers with a binder and molding them together. At that time, as the dimensions of the constituent elements become smaller, the resulting wood board becomes more uniform and the surface becomes smoother, but the strength and rigidity decrease and the density increases.
On the contrary, when the size of the constituent elements is increased, the strength and density of the original wood are approached, but such a wood board is non-homogeneous and the surface unevenness tends to be large.

On the other hand, as a flooring material, as shown in FIG. 11, a flooring material is generally used in which a decorative veneer 3 is bonded to one surface of a plywood 3a. Plywood, which is the raw material for such flooring, is a board that is made by bonding and laminating a plurality of veneer veneers, etc. so that the grain directions are orthogonal to each other, and has sufficient strength and rigidity to be used as a flooring. And the surface is smooth. Therefore, in order to apply the wood board as described above to a flooring material in place of the plywood, it is necessary to give the wood board the strength and rigidity equal to or higher than that of the plywood and the surface smoothness.

[0004]

However, for example, in a wood fiber integrated board having wood fibers obtained by defibrating wood as a constituent element, a wood board having a uniform and smooth surface can be obtained, while floor materials are used. However, the strength is insufficient, and there is a drawback that if the wood board is made thick to increase the strength, the weight increases and it becomes difficult to handle. Further, as shown in FIG. 2, in the directional wood thin plate laminated plate in which the wood thin pieces 2a are arranged in a substantially constant direction and bonded with a binder, and integrally molded, the strength is improved, but There was a problem that the surface was uneven and had large irregularities. Further, in this type of laminated plate, since the thin wooden pieces 2a having different thicknesses are randomly stacked, there is a drawback that unevenness is likely to occur on the surface when the thick thin wooden pieces are stacked on the surface layer. In addition, when such a directional wood thin plate laminated board is applied to a flooring material, there arises a problem that irregularities of the underlying directional wood thin laminated plate appear on the surface of the decorative veneer.

Therefore, the present inventors have previously proposed Japanese Patent Application No. 5-17.
4564, length 50-75 mm, width 6
50 to 100 mm in length and 6 to 100 mm in width on both sides of a directional wood laminated plate composed of small wood flakes of up to 50 mm
We have applied for a patent for a wood board with a new structure in which laminated surface laminated directional wood flakes made of large wood flakes are laminated. The wood board according to this patent application was excellent in that it had a smooth surface, was lightweight, and had sufficient strength and rigidity.

However, when cutting a thin piece of wood used for the wood board from a raw material such as a log, usually, the raw material is pressed against a rotary disk having a plurality of rotary blades to slice the raw material. Even when cutting under the same conditions, there is a tendency that it is not possible to form wood flakes of an allowable size because the size of the wood flakes tends to vary depending on the state of the cutting device and cutting blade. It was When a wood board is manufactured using such unevenly-sized pieces of wood,
There is a problem that the smoothness of the wooden board surface deteriorates. In addition, when wood flakes of non-uniform size are used, even if they have moderate smoothness immediately after production, under the conditions of high temperature and high humidity, the wood flakes expand and contract, and the surface gradually grows. However, there was a problem that the smoothness of the was deteriorated.

The present invention has been made in view of the above circumstances, and can be manufactured by efficiently utilizing a thin piece of wood.
An object of the present invention is to provide a method for manufacturing a wooden board which is lightweight, has a smooth surface, has sufficient strength and rigidity, and does not deteriorate in surface smoothness even in a hot and humid environment.

[0008]

In order to solve the above-mentioned problems, the invention described in claim 1 is to perform a cutting step of cutting wood to form wood flakes, and stacking a large number of the wood flakes to form an aggregate. In a method of manufacturing a wood board, which comprises a forming step of forming and a pressing step of solidifying the aggregate by thermocompression bonding using an adhesive, before the forming step, from the plurality of thin wood pieces, a length is selected. 50-75m
m, a small wood flakes with a size distribution of 6 to 50 mm and a large wood flakes with a length distribution of 50 to 100 mm and a width of 6 to 100 mm are selected, and the forming process is performed in a plurality of steps. The pieces are divided and small wood flakes and large wood flakes are deposited one or more times each to form an aggregate, which is thermocompression-bonded and solidified to form a core material consisting of small wood flakes and a surface layer consisting of large wood flakes. This is to form a wood material provided with wood.

In order to solve the above-mentioned problems, the invention as set forth in claim 2 includes a cutting step of cutting wood to form a thin piece of wood, and a forming step of depositing a large number of the thin pieces of wood to form an aggregate. In a method for manufacturing a wooden board, which comprises a pressing step of solidifying this aggregate by thermocompression bonding using an adhesive, a length of 50 to 75 mm and a width of 6 to
Forming a small piece of wood with a size distribution of 50 mm, forming a large piece of wood with a size distribution of 50 to 100 mm in length and 6 to 100 mm in width in another cutting process, and dividing the forming process into multiple steps. , Accumulating small wood flakes and large wood flakes one or more times to form an aggregate, and thermocompressing and solidifying the aggregate to form a core material of the small wood flakes and a surface material of the large wood flakes. And a wooden board having the following.

[0010]

In the present invention, from the wood thin pieces formed in the cutting step, large wood thin pieces having a length of 50 to 100 mm and a width of 6 to 100 mm and small wood thin pieces having a length of 50 to 75 mm and a width of 6 to 50 mm are selected. It is used to form the surface layer material with large wood flakes and the core material with small wood flakes, so the core material consisting of small wood flakes secures the necessary strength and rigidity, and the good smoothness of the surface is exhibited by the large wood flakes. To do. Therefore, a wood material having excellent strength and rigidity as a whole and having a smooth surface can be obtained. The forming process is divided into a first forming process, a second forming process, and a third forming process to deposit large-sized wood flakes, small-sized wood flakes, and large-sized wood flakes, which are thermocompression-bonded and solidified. A wood board having a surface material having excellent smoothness on both sides of a core material having strength and rigidity can be obtained. In this type of wood board, the strength of the surface layer greatly contributes to the strength of the whole wood board, but the strength can be further improved by increasing the size of the thin wood piece on the surface layer.

Further, when forming a thin piece of wood, a large-sized thin piece of wood is formed in a dedicated cutting step, and a small-sized thin piece of wood is formed in a dedicated cutting step. It is possible to easily obtain small timber flakes, and to obtain surface smoothness by using large timber flakes to form a surface layer material.By forming a core material using the small timber flakes, High rigidity and strength can be obtained.

The present invention will be described in detail below. First,
Before describing the method of the present invention, an example of the structure of a wood board obtained by the method of the present invention will be described with reference to FIG.
In the figure, 1 is a core material, and this core material 1 has a length of 50 to 75 m.
It is formed from a core wood thin piece laminated plate made of small wood thin pieces of m and a width of 6 to 50 mm. On both sides of the core material 1,
A wood board A is formed by laminating surface layer materials 2 formed of a surface-directional directional wood thin piece laminated board composed of large wood thin pieces having a length of 50 to 100 mm and a width of 6 to 100 mm.

The core material 1 of the wooden board A has a length of 50 to 7
A core wood thin plate laminated plate composed of a small wood thin piece having a width of 5 mm and a width of 6 to 50 mm is used. In this laminated wood thin plate, thin small wood thin pieces having a thickness of 0.4 to 0.8 mm are arranged in a substantially random direction or in a fixed direction, and they are joined by an adhesive such as a foaming binder. , Integrated molding. The direction of the arrangement of the small wood flakes may be a direction orthogonal to the direction of the wood flakes of the surface layer or an arbitrary direction. The direction of the small timber flakes does not mean the direction of a specific side of the thin timber shape, but refers to the grain direction of the small timber flakes regardless of the shape.

This small piece of wood has a length of 50 to 75 m.
m, the width is 6 to 50 mm, and the thickness is preferably in the range of 0.1 to 0.8 mm. Small wood flakes are 50m long
If it is less than m, the bending strength of the laminated plate decreases, and it is not suitable for applications such as flooring. Further, when the length exceeds 75 mm, it becomes difficult to continuously connect the wood grain over the entire small-sized wooden thin piece, so that the bending strength does not increase according to the length. As these small wood flakes, flakes of red pine, larch, ezo pine, todo pine, aspen, lodgepole pine and the like are preferably used, but the tree species is not particularly limited.

These small pieces of wood are bonded and molded integrally by a foaming binder. This foamable binder is one that causes small wood flakes to be bonded to each other in the core wood thin plate laminated plate, and that itself foams, and preferably the resin component is present only at the intersection of the small wood flakes. By using a foam cell to spread the small gaps of small wood flakes, the amount of resin component used can be reduced and the density of the directional wood flakes laminated plate can be reduced. In addition, in this specification, a binder having a property of foaming is referred to as a "foamable binder", and a foamable binder which has been foamed is referred to as a "foaming binder".
Shall be called.

The expandable binder may be composed of a resin that self-expands, or may be composed of a non-expandable resin and a foaming agent. Examples of self-foaming resins include foamable polyurethane resins. Examples of the non-foaming resin that foams with a foaming agent include polyurethane resin, polystyrene resin, epoxy resin, polyvinyl chloride resin, phenol resin, urea resin, or a mixture thereof. As the foaming agent, a volatile foaming agent such as CC
l ₃ F, CCl ₂ F ₂ , or CCl ₂ F-CClF ₂
Etc., or a thermally decomposable foaming agent such as azodicarbonamide, azohexahydrobenzonitrile, 2,2′-azoisobutyronitrile, benzenesulfohydrazide, or N, N′-dinitroso-N, N′-dimethylterephthalate. Examples include amide.

Further, these expandable binders may contain non-expandable binders such as urea resin, melamine resin and phenol resin. The mixing ratio of these can be appropriately adjusted according to the density of the target directional wood thin plate laminate, but the mixing ratio of the expandable binder and the non-expandable binder is preferably 4: 1 to 1: 4. Is.

The ratio of the expandable binder to the small wood flakes in this laminated wood flakes laminated board is 1
It is preferably 15 to 30 parts by weight with respect to 00 parts by weight. Furthermore, the thickness of the laminated wood thin plate is 5 mm.
It is preferable to set it to ˜13 mm, and its density is 0.40.
It is preferably set to be about 0.65 g / cm ³ . The density is 0.
If it is less than 40 g / cm ³ , the strength of the plate will be insufficient, and if the density is more than 0.65 g / cm ³ , the weight of the entire material will increase and it will be difficult to handle. The bending Young's modulus of this laminated wood thin plate is 40 to 80 × 10 ² MP
It is preferably a. Young's modulus of bending is 40 × 10 ^2.
If the pressure is less than MPa, the bending of the wood board becomes larger than the specified value. If it exceeds 80 × 10 ² MPa, the appropriate elasticity required for walking is insufficient.

In the above-mentioned wood board A, the surface layer material 2 laminated on both sides of the core material 1 is a surface direction directional wood flakes laminated board composed of large wood flakes having a thickness of 0.1 to 0.8 mm. Used. This surface directional laminated wood thin plate has a length of 50 to 1
Large thin wood flakes 2a shown in FIG. 2 having a length of 00 mm and a width of 6 to 100 mm are arranged in an arbitrary direction, and they are bonded by a foaming binder to be integrally molded. In addition, the arrangement direction of the large-sized wood thin pieces forming the surface layer material 2 is preferably aligned in a certain direction, and is preferably arranged in a direction orthogonal to the arrangement direction of the large-sized wood thin pieces in the core material 1.

The above-mentioned large piece of wood has a length of 50 to 10
0 mm, preferably 70-100 mm, width 6-100
mm, preferably 20 to 100 mm is used. If the length of the large-sized wood flakes is less than 50 mm, the bending strength of the laminated plate decreases, which is not suitable as a floor material, and the surface smoothness is poor. On the other hand, even if the length exceeds 100 mm, the effect of surface smoothing is unlikely to increase according to the length. The thickness of the large-sized wood flakes is preferably 0.1 to 0.8 mm, and if the thickness exceeds 0.8 mm, the surface of the obtained surface-directional directional wood flakes laminated plate will not be smooth. Further, as the large-sized wood flakes, flakes such as red pine, larch, ezo pine, todo pine, aspen, lodgepole pine and the like are preferably used, but the tree species is not particularly limited.

It is preferable that the large piece of wood having a length of 50 to 100 mm and a width of 6 to 100 mm which forms the surface-directional directional wood piece laminated plate is previously acetylated. When acetylating large wood flakes, the wood flakes should have a water content of 3%.
Hereinafter, it is preferable that after drying to preferably 1% or less, it is contacted with vaporized vapor such as acetic acid, acetic anhydride or chloroacetic acid to acetylate in the vapor phase (degree of acetylation 12 to 20%).

The length is 50 to 100 mm and the width is 6 to 100
The large wood pieces of mm are bonded and integrated by a binder. The binder used for this surface layer material may be the foamable binder as described above, or a non-foamable binder or a mixture thereof, but in practice, it is releasable from the mold for molding. In terms of
Those mainly composed of a non-foaming binder are preferable. The mixing ratio of them can be appropriately set in consideration of the density and releasability of the target surface-oriented wood thin plate laminate.

The ratio of the binder to the large-sized wood flakes having a length of 50 to 100 mm and a width of 6 to 100 mm in the surface-oriented directional wood flakes laminated plate is as follows.
It is preferably 5 parts by weight or more with respect to 0 parts by weight.
When the amount of the binder added is 5 parts by weight or less with respect to 100 parts by weight of large-sized wood flakes, the strength of the obtained surface-directional directional wood flakes laminated plate becomes insufficient. The thickness of the surface-directional directional wood thin plate is 1 to 5, preferably 1 to 2 m.
m. Furthermore, it is preferable that the density of the surface-oriented wood thin plate laminate is 0.40 to 0.65 g / cm ³ . When the density is less than 0.40 g / cm ³ , the strength of the plate becomes insufficient, while when the density is more than 0.65 g / cm ³ , the weight of the entire material increases and it becomes difficult to handle. The Young's modulus of bending of this surface-oriented laminated wood thin plate is 40.
It is preferably ˜80 × 10 ² MPa. Further, the composition ratio of the thickness of the surface layer material (sum of thicknesses on both sides) and the thickness of the core material is 50:50 to 30:70, preferably 50:50 to.
40:60 is good.

Next, a first example of the method for manufacturing a wooden board according to the present invention will be described. In the method of this example, the wood board A is manufactured using the steps shown in FIG. First, in the cutting step 4, a log as a raw material is shown in FIG.
A large number of thin wood pieces having an average thickness of 0.5 mm, an average length of 75 mm, and a width of 30 mm are prepared by performing a slice cutting process using. The cutting device 5 shown in FIG.
Conveyor device 7 that continuously conveys, and this conveyor device 7
Connected to and sliced logs to cut a large amount of wood flakes 9
Rotary cutter device 8 with a cutting blade 8a for creating
Is to have. Since the cutting device 5 shown in FIG. 4 is an example of a cutting device, a cutting machine having any structure may be used as long as it is a device capable of manufacturing a thin piece of wood by cutting wood such as logs. .

After the wood thin pieces 9 ... Shown in FIG. 4 are prepared, the wood thin pieces 9 ... Are sent to the drying step 10 and dried by the drying device. Also, in this drying process,
It is preferable to acetylate the wood thin pieces 9 ... As needed. When acetylating wood flakes 9 ...
The wood flakes are dried to a water content of 3% or less, preferably 1% or less, and then contacted with vaporized vapor of acetic acid, acetic anhydride, chloroacetic acid or the like to acetylate (acetylation degree 12 to 12 20%) is preferable.

Next, a binder (adhesive) is applied to the dried wood thin pieces 9 ... In a coating step 11.
The binder may be expandable, non-expandable or a mixture thereof, as described above.
To apply the binder, a drum rotation type mixing device such as a rotary drum blender is used to put the wood thin pieces 9 ... into the drum, and a molten adhesive is sprayed, and the adhesive and the wood thin pieces are rotated while rotating the drum. It is preferable to mix 9 ... because a large amount of wood flakes 9 ... can be treated at one time. In addition, you may perform the 2nd drying process 11a after the application process 11 as needed, and dry-process the wood thin piece 9 ....

After the coating process 11 is completed, a large number of wood flakes 9 ...
Is selected as a small piece of wood having a length of 75 mm or less and a large piece of wood having a length exceeding that. Here, for example, from among the wood thin pieces 9 ... Having a length distribution as shown in FIG.
Those having a length of 75 mm or less and those having a length exceeding that may be selected. As an example of a specific sorting method, as shown in FIG. 6, a blower 15 is operated to generate wind, and a plurality of thin wood pieces 9 are dropped into the wind from a conveyor 16 such as a belt conveyor. The containers 17 and 18 are installed side by side on the leeward side. By this operation, large wood flakes with a large surface area fall into the leeward side container 18, and small wood flakes with a small surface area fall into the windward side container 17, so that the wood flakes can be selected. Here, the density is 0.43 ~
Considering that it is 0.5g for a thin piece of aspen wood with a size of about 0.45 and a size of 75 × 30 × 0.5, in advance, determine how long the flight distance will be based on the predetermined wind speed and weight. If it is calculated, the wood thin pieces can be reliably selected by the selection method using the containers 17 and 18.

As another selection method, a screen 19 shown in FIG. 7 may be used, and the thin wood pieces 9 ... Can be dropped from the belt conveyor 16 onto the screen 19. In this case, if the sieve 19 has 75 mm
The wood flakes longer than 5 mm are deposited on the sieve 19, and the small wood flakes pass through the eyes of the sieve 19 and fall down so that they can be sorted. Although only one sieve may be provided,
It is also possible to provide a plurality of sieves having different mesh sizes and perform sieving in stages. In this embodiment, the size selection step is performed after the binder is applied in the application step, but the size selection may be performed before the binder application and the binder may be applied individually.

Next, a part of the large-sized wood thin pieces selected in the selecting step 12 are conveyed to the first forming step 20. In this first forming step 20, a large number of large-sized wood flakes are fed onto the belt of a conveyor such as a belt conveyor, and large-sized wood flakes successively dropped from the belt are deposited in layers on the hot pressing plate to form a first layer. Form an aggregate. At this time, it is preferable to deposit the large-sized wood flakes so that they are aligned in substantially the same direction. Next, the small wood flakes selected as described above are subjected to the second forming step 2
1 and is deposited in layers on the first stack to form a second stack. Subsequently, a part of the large-sized wood thin pieces selected as described above is conveyed to the third forming step 22,
A third stack is formed by depositing layers on the second stack.

Next, the third integrated body is sent to a pressing step 23, and the third integrated body is compacted by a pressing device such as a thermocompression molding machine to obtain a wood board A shown in FIG. In this wood board A, the surface layer materials 2 and 2 are formed from the deposits of large-sized wood flakes, and the core material 1 is formed from the deposits of small-size wood flakes. The hot-pressing conditions in the pressing step are a pressure of 1 to 2 MPa and a temperature of 150 to 200.
It is preferable that the temperature and the temperature are set to a target thickness (mm) × 5 to 120 seconds. Wood board A thus obtained
Preferably has a density of 0.4 to 0.65 g / cm ³ and a bending Young's modulus of 40 to 80 × 10 ² MPa.

Next, a case where a floor material is manufactured using the wood board A will be described. The floor material B shown in FIG. 8 can be obtained by attaching the separately prepared decorative veneer 3 to the surface of the wooden board A molded as described above with an adhesive. At that time, the surface of the plate material may be polished by a conventionally used method, and the decorative veneer 3 may be bonded to the polished surface. The decorative veneer 3 used here is not particularly limited, and a decorative veneer having a thickness of about 0.2 to 0.8 mm which has been conventionally used such as an oak veneer can be used. Since the surface is smooth and flat, thin decorative veneer can be used. The surface of the decorative veneer may be coated with urethane or the like having a thickness of about 40 to 60 μm.

The directional wood flakes laminated plate used as the core material 1 in the wood board A having the above-mentioned structure has a large strength especially in the arranging direction because the small wood flakes are arranged in substantially the same direction. Further, in this directional wood thin plate laminated board, since it is molded and integrated using an adhesive such as a foamable binder, the amount of resin used is small, the density of the resulting wood board A is low, and the foamed binder itself is Since it contains micro bubbles, it is made flexible, has a buffering effect against external force, and is not easily destroyed. Further, in the wood board A having the above-mentioned structure, since the surface smoothing directional wood flakes laminated plate composed of large wood flakes is laminated on both surfaces of the core material 1 of the directional wood flakes laminated board by simultaneous molding, It is smooth and has improved strength and rigidity. Therefore, such a wooden board A
The floor material B formed by bonding a decorative veneer to the surface has a smooth surface and has sufficient strength and rigidity.

In the wood board 1 manufactured as described above, when the large-sized wood flakes forming the surface layer materials 2 and 2 are acetylated, the wood board and the floor material are protected against insects, rots, and fungi.
It is possible to improve water resistance / moisture resistance and dimensional stability. Further, according to the method of the present invention, it is possible to effectively use a raw material that has been conventionally discarded, and it is effective in protecting wood resources.
Further, such a raw material is low in price, and the raw material cost can be reduced.

Next, a second example of the method of the present invention will be described. In the method of this example, the wood board A is manufactured using the steps shown in FIG. First, the cutting steps 30 and 31 are provided, a cutting device dedicated to each cutting step is provided to cut a log as a raw material, and the cutting step 30 preferably has an average length of 75 mm.
A large-sized wood thin piece exceeding the above is prepared, and in the cutting step 31, a small-sized wood thin piece having an average length of 75 mm or less is preferably prepared.
In this case, for example, the cutting device provided in the cutting step 30 is adjusted so that the average length is 80 mm, the width is 30 mm, and the thickness is 0.5 mm.
The average length of 50m
To be able to produce small timber flakes of m, width 20 mm, thickness 0.5 mm. Fig. 10 shows a normal distribution state and an average length of 50 mm after cutting a large piece of wood with an average length of 80 mm.
The normal distribution state of the small wood slices after cutting was shown.

The large-sized wood thin piece manufactured in the cutting step 30 is conveyed to the first forming step 35 and the third forming step 36 through the drying step 32, the coating step 33, and the drying step 34, and the small size produced in the cutting step 31. For wood flakes, a drying step 37, a coating step 38, and a drying step 39
And then conveyed to the second forming step 40. In addition, in the drying step 32, the acetylation treatment can be performed if necessary. First forming step 3
5, the second forming step 40, and the third forming step 36 have the same structure as the forming steps described in the previous example. In these steps, a deposit of wood flakes is formed, and the next pressing step 23 is performed. The wood board A can be manufactured by hot pressing the deposit.

Also in the above steps, it is possible to manufacture a wood board having the same structure as the wood board A described in the first example. In the method of this example, a cutting step 30 having a cutting device for forming large-sized wood flakes and a cutting step 31 having a cutting device for forming small-sized wood flakes are provided. Therefore, as shown in FIG. It is possible to easily obtain a thin piece of wood having a size distribution by adjusting the cutting edge or scribe of each cutting device. Therefore, by adjusting the cutting device, it is possible to use large-sized wood thin pieces and small-sized wood thin pieces having a desired size distribution, and it is possible to manufacture a wooden board having desired strength, rigidity, and surface smoothness.

Next, the method of the present invention will be specifically described based on Examples. (Example 1) As a material for the laminated wood thin plate of the core portion forming the core material, a small wood thin piece having a length of 50 to 75 mm, a width of 6 to 50 mm and a thickness of 0.1 to 0.8 mm is shaving. It was made with a machine (made by 〓 Iwakura Gumi). Next, 10 parts by weight of a foaming urethane resin (crude MDI manufactured by Sumitomo Bayer Urethane Co., Ltd.) was prepared, 100 parts by weight of the above-mentioned thin wood pieces were put in a rotating drum rotating at a low speed, and the mixture was naturally dropped in the drum. At this time, the foamable binder was applied to the wood flakes for the core material by spraying.

As a material for the surface-directional directional wood thin plate, which is a surface layer material, the length is 50 to 100 mm and the width is 6 to 10.
A large piece of wood having a thickness of 0 mm and a thickness of 0.1 to 0.8 mm was produced by a shaving machine (manufactured by Iwakura Gumi Co., Ltd.). Next, 10 parts by weight of the aqueous phenol binder was prepared and placed in a rotary drum rotating at a low speed, and the above-mentioned wood flakes 1
The binder was applied to the wood flakes for the surface layer material by adding 00 parts by weight and spraying with a spray when spontaneously dropping in the drum.

First, half of the large-sized wood thin pieces for the surface layer material coated with the binder are arranged in a substantially constant direction on the hot pressing plate to be sprayed and deposited to form the first integrated body, on which the first integrated body is formed. The small wood flakes for the core material coated with the expandable binder were scattered so that the arrangement direction of the small wood flakes was orthogonal to the arrangement direction of the large wood flakes for the surface layer material. Further, the remaining large-sized wood flakes for the surface layer were arranged and sprayed in the same direction as the large-sized wood flakes for the surface layer that were initially scattered to form a third aggregate having a thickness of 250 mm. The aggregate is set at a temperature of 160 ° C. and a pressure of 2 so that the thickness becomes 12 mm.
Simultaneous hot pressing was performed at MPa for 10 minutes. The surface of the wood board thus molded was sufficiently smooth.

The density of the wood board produced as described above,
The bending strength and bending Young's modulus were measured. The bending strength was evaluated based on JIS-A5908. As a result, the density was 0.58 g / cm ³ , and the bending strength was 66MP.
a, Young's modulus of bending was 73 × 10 ² MPa.

The same measurement as above was carried out on the plywood having the same thickness as the wood board of Example 1 measured above. As a result, the density was 0.58 g / cm ³ , and the bending strength was 4
The bending Young's modulus was 9 MPa and the bending Young's modulus was 52 × 10 ² MPa. From these results, it can be seen that the wood board produced by the method of the present invention has a density equal to or lower than that of plywood, and has a bending strength superior to that of plywood.

(Production Example) A decorative veneer composed of an oak veneer having a thickness of 0.3 mm and an aqueous polymer isocyanate-based adhesive (Koyo Sangyo, KR7800) were formed on one surface of the wood board produced in Example 1. Use, temperature 110 ℃, pressure 10M
Pa was adhered for 3 minutes. Since the surface of the wood board was smooth, the decorative veneer was well adhered. Further, after polishing the surface, urethane coating having a thickness of about 50 μm was applied to obtain a floor material. The floor material obtained had a smooth and good appearance.

The bending flexure of the flooring material thus produced was evaluated based on JAS. That is, the sample size of the floor material is 300 mm (width) x 1800 mm (length) x 12 mm
As (thickness), the displacement (A) when a load of 21 kg weight is applied to the load rod placed at 700 mm in span and placed orthogonal to the center of the span, and a load of 9 kg weight is also applied. It evaluated by the difference (AB) with the displacement (B) when it was. The smaller this difference is, the stronger the rigidity is. According to the JAS standard for floor materials, the value of this bending deflection is
It must be 3.5 mm or less. Regarding the floor material,
When the above evaluation is carried out, the bending deflection value is 2.3 m.
It was m. Therefore, the flooring material of the present invention has a flexurally flexible J
It was found that the product satisfies the AS standard and has sufficient rigidity to be used as a floor material.

[0044]

As described above, according to the method of the present invention, a length of 50 to 10 is obtained from a thin piece of wood formed in the cutting process.
A large piece of wood with a width of 0 mm and a width of 6 to 100 mm, and a length of 50
~ 75 mm, width 6 ~ 50 mm small wood flakes are selected and used, and large wood flakes form the surface layer material and small wood flakes form the core material, so the required strength and rigidity are small wood flakes. Since the large timber flakes exhibit good smoothness of the surface that is secured, it is possible to obtain a wood material having excellent strength and rigidity as a whole and having a smooth surface. Further, even if the inner core material is partially hard and soft or has a thin thickness, it is possible to obtain a wood board which is uniform as a whole wood board and has a smooth surface. Furthermore, since the thin wood pieces are bonded to each other in the core material and the surface layer material with an adhesive, it is possible to reduce the density and obtain a lightweight and high-strength wooden board.

Further, the forming process is divided into a first forming process, a second forming process and a third forming process to deposit large wood flakes, small wood flakes and large wood flakes and perform thermocompression bonding. If solidified, it is possible to manufacture a wood material having a surface material having excellent smoothness on both surfaces of a core material having high strength and rigidity.

Further, when forming a thin piece of wood, a large-sized piece of wood is formed by a dedicated cutting step, and a small piece of wood is formed by a dedicated cutting step. It is possible to easily obtain small timber flakes, and to obtain surface smoothness by using large timber flakes to form a surface layer material.By forming a core material using the small timber flakes, High rigidity and strength can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a wooden board manufactured by carrying out an example of the method of the present invention.

FIG. 2 is a surface view showing an example of a directional wood thin plate laminated plate.

FIG. 3 is a process chart showing a first example of the method of the present invention.

4A is a configuration diagram showing an example of a cutting device used in the method of the present invention, and FIG. 4B is a partially enlarged view of the cutting device.

FIG. 5 is a diagram showing an example of a length distribution of a thin piece of wood used for carrying out the method of the present invention.

FIG. 6 is a configuration diagram showing an example of a sorting device used for carrying out the method of the present invention.

FIG. 7 is a configuration diagram showing another example of a sorting apparatus used for carrying out the method of the present invention.

FIG. 8 is a cross-sectional view showing a structure of a flooring material obtained by using the wooden board.

FIG. 9 is a process drawing showing a second example of the method of the present invention.

FIG. 10 is a diagram showing another example of the length distribution of the wood flakes used for carrying out the method of the present invention.

FIG. 11 is a cross-sectional view showing an example of a conventional wood board.

[Explanation of symbols]

A ... Wood material, 1 ... Core material, 2 ... Surface material, 3 ... Decorative veneer,
31 ... Plywood, 4 ... Cutting process, 10, 32, 34, 3
7, 39 ... Drying process, 11, 33, 38 ... Coating process,
12 ... Size selection step, 20, 35 ... First forming step, 21, 40 ... Second forming step, 2
2, 36 ... Third forming step, 23 ... Pressing step.

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[Procedure amendment]

[Submission date] August 24, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 4

[Correction method] Change

[Correction content]

FIG. 4 is a configuration diagram showing an example of a cutting device used in the method of the present invention and a partially enlarged state thereof.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akihiro Hoshikawa 10-1 Nakazawa-machi, Hamamatsu-shi, Shizuoka Prefecture Yamaha Stock Company

Claims (2)

[Claims] 1. A cutting step of cutting a wood piece to form a thin piece of wood, a forming step of depositing a large number of the thin piece of wood to form an aggregate, and a solidification of the aggregate by thermocompression bonding using an adhesive. In the method for manufacturing a wood board including a pressing step, the small wood flakes having a size distribution of 50 to 75 mm in length and 6 to 50 mm in width are selected from the large number of wood flakes before the forming step. 50 to 100 mm, width 6 to 1
In addition to performing a sorting process to select large wood flakes with a size distribution of 00 mm, the forming process is divided into multiple processes, and large wood flakes and small wood flakes are deposited at least once each to form an aggregate. Then, a method for producing a wood board, which comprises thermocompressing and solidifying this aggregate to produce a wood board having a core material made of small wood pieces and a surface material made of large wood pieces. 2. A cutting step of cutting a wood piece to form a thin piece of wood, a forming step of depositing a large number of the thin piece of wood to form an integrated body, and a solidification of the integrated body by thermocompression bonding using an adhesive. In a method for manufacturing a wooden board including a pressing step, a length of 50 to 75 mm and a width of 6 to 50 mm in a predetermined cutting step.
Forming a small wood flakes with a size distribution of, and forming a large wood flakes with a size distribution of 50-100 mm in length and 6-100 mm in width in another cutting process, and dividing the forming process into a plurality of processes, Depositing small wood flakes and large wood flakes one or more times each to form an aggregate,
A method for producing a wood board, comprising: producing a wood board comprising a core material made of small wood flakes and a surface layer material made of large wood flakes by thermocompression-solidifying this aggregate.