JPH10244514A - Composite board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide composite board suited for the use as a construction material or a furniture member. SOLUTION: This composite board comprises wooden fiber layers 1, 1 arranged on the front face only or the front face and the back face and a wooden cut piece layer 2 arranged on the back face of the wooden fiber layer 1 of the front face or between the wooden fiber layers 1, 1 of the front/back faces. The wooden fiber layer 1 is of a coniferous wood and a decorative sheet is stuck to the surface of the front wooden fiber layer 1. The wooden fiber layer 1 which has an outstanding surface smoothness and is made of the white coniferous wood, is formed on the front face or the front/back faces of a low-priced wooden cut piece. Therefore, the wooden fiber layer 1 shows superb decorative properties when it is coated for surface decorating treatment. Further, this composite board is of such a high quality that the problem of expansion and shrinkage due to the absorption of water and moisture native to a wooden cut piece board 2 is solved through a restricting action by the wooden fiber layer 1 obtained from the coniferous wood of uniform quality.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite board used as a building material or a member for furniture.

[0002]

2. Description of the Related Art Generally, sawn timber, plywood, laminated veneer (LV)
L., LVB) and other wood boards are used in a wide variety of applications as architectural and furniture components, but since they have a certain fiber direction, they expand and contract due to the absorption and release of moisture, In particular, there was a problem that the expansion rate in the direction perpendicular to the fiber direction was large and the dimensional stability was lacking.

[0003] In addition, since there is a conduit groove on the surface, it is necessary to perform a base treatment such as a sealer treatment and a sealing treatment at the time of processing such as surface coating and paper sticking.

[0004] Furthermore, due to the recent depletion of high-quality trees, such wooden boards tend to be expensive. Therefore, wood chipboards made by bonding small pieces of wood are inexpensive materials suitable for effective use of resources. Attention has been paid to it.

[0005]

However, since the wood chipboard is obtained by bonding wood chips, the surface is very rough and it is difficult to make up the surface. Therefore, in general, a thick decorative sheet tends to be used, which is expensive.

[0006] In addition, the wood chipboard is a collection of wood chips having low surface peel strength and individually having complicated fiber directions.
The expansion and contraction due to the absorption and release of water is remarkable, and the decorative sheet is easily peeled or cracked. Furthermore, when a decorative sheet is adhered using a large amount of an adhesive such as urea resin or phenol resin to prevent this, a strong formalin smell remains. It was inside and uncomfortable.

As an improvement of such a wood chip board, there is known a three-layer board in which the wood chips of the front and back layers are dense and thin, and the wood chips of the central layer are coarse. This 3
The layer board has a certain surface smoothness compared to a single-layer wood chipboard, and the bending strength is improved,
It still has the fundamental disadvantages of wood chipboard as described above.

Further, if the wood chips of the surface layer are made short (fine) and thin in order to enhance the surface smoothness of the three-layer board, the bonding force (entanglement) between the wood chips becomes small, and the same applies. In order to maintain the bending strength, there is a problem that a large amount of adhesive is required.

[0009]

In view of the above situation,
The present inventor has conducted intensive studies to solve the problems of inexpensive wood chipboard, and as a result, has completed the present invention.

That is, according to the present invention, the wood fiber layer is provided only on the front surface or the front and back surfaces, and the wood chip layer is provided on the back surface of the front wood fiber layer or between the front and back wood fiber layers. A composite board, wherein the wood fiber layer is a wood fiber layer obtained from softwood.

According to a second aspect of the present invention, a wood fiber layer is provided only on the front surface or the front and back surfaces, and a wood chip layer is provided between the back surface of the front wood fiber layer and the front and back wood fiber layers. A composite board, wherein the wood fiber layer is a wood fiber layer obtained from softwood, and the surface of the wood fiber layer is subjected to a cosmetic treatment by painting.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A composite plate according to the present invention will be described below with reference to the drawings.

FIG. 1 shows the structure of a composite board according to one embodiment of the present invention, in which wood fiber layers 1 and 1 are arranged on the front and back surfaces, and a wood chip layer 2 is arranged between them.

The wood fiber layer 1 is a wood fiber layer using wood fibers obtained from softwood such as pine, cedar and cypress as a raw material.

The wood fibers obtained from softwoods are finer and slender than the wood fibers obtained from broadleaf trees, and exhibit a white color. Therefore, the wood fiber layer obtained is smooth and white, and the surface is treated by painting. It is suitable for applying an adhesive makeup treatment for thin veneer, decorative paper, etc.

The wood chip layer 2 includes small-diameter wood, sawmill waste,
Wood chips obtained from raw wood cores, waste wood chips and the like are used. In addition, a wood chipboard obtained by adding an adhesive to a small piece obtained by cutting and crushing and hot-pressing it can be used.

The specific gravity of the wood fiber layer 1 obtained from the softwood is greater than the specific gravity of the wood chip layer 2. Thereby, when an external force is applied to the surface of the composite board, in addition to the compressive strength of the wood fiber layer 1 having a large specific gravity on the surface side obtained from the softwood material, the tensile strength of the wood fiber layer 1 obtained from the softwood material, Due to the binding force of the wood fiber layers 1 and 1 having a large specific gravity on the back side obtained from these softwoods, excellent bending Young's modulus (rigidity) is exhibited, and a wood chip layer 2 having a small specific gravity is disposed at the center. Thereby, a composite plate having high strength can be obtained while reducing the overall weight and cost.

The wood chip layer 2 has a specific gravity of 0.25-1.
05. Specific gravity 0.25
A composite board using a wood chip layer that is less than 10% has an insufficient bending Young's modulus, and using a wood chip layer having a specific gravity exceeding 1.05 increases the overall weight of the composite board. Is not preferred.

In the composite board of the present invention, the wood fiber layer 1 obtained from a softwood material which is stable and stable against expansion and contraction caused by the absorption and release of water and has excellent surface smoothness is arranged on the surface. As described above, it is possible to easily and beautifully apply makeup by applying a decorative sheet such as painting, a thin veneer, or decorative paper.

The wood fiber layer obtained from softwood has a good bending strength and a good surface compressive strength, since the fibers are entangled to form a layer. Therefore, the composite plate is excellent in bending strength and surface hardness while being lightweight and inexpensive to manufacture.

The method for producing a composite board according to the present invention will be described. As shown in FIG. 2, a coniferous wood fiber production line and a wood chip production line are used to separate coniferous wood fiber and wood chip, respectively, to which an adhesive has been added. Obtained, a mat layer of wood fiber made of softwood wood fiber with an adhesive added to the front and back surfaces, and laminated such that wood chips are arranged between mat layers of wood fiber obtained from the front and back softwood materials. Thereafter, by pressing and bonding and integrally forming, a composite board can be manufactured in which lamination is performed so that a wood chip layer is disposed between wood fiber layers obtained from softwood on the front and back.

Each step will be described in detail below. (Coniferous wood fiber production line) Pine, cedar,
After cutting softwood such as cypress into chips, defibrate according to the usual method,
It is possible to use one dried to a water content of 20% or less, preferably 10% or less. Most of these coniferous wood fibers have a length of about 1 to 30 mm and a diameter of about 2 to 300 μm. The coniferous wood fiber has a shape like a temporary vessel or a bundle of cells, and the cell wall around the fiber is often torn or cracked.

A urea resin-based adhesive,
A phenol resin adhesive, a melamine resin adhesive, an epoxy resin adhesive, an isocyanate / vinyl acetate resin adhesive, or a modified synthetic resin adhesive thereof is added and mixed.

The coniferous wood fibers to which the adhesive has been attached are put into a hot air duct and dried while being blown. The air blowing speed at this time is about 15 to 20 m / sec, but is adjusted over a wide range depending on the specific gravity of the coniferous wood fiber, the feeding amount, the processing capacity of the preceding and following steps, and the like.

[0025] By this hot air blowing, the coniferous wood fibers are reduced to 6
After being dried to a water content of about 15%, it is conveyed to the forming devices 3 and 3 (FIG. 3). (Wood chip production line) small diameter wood, sawn wood, raw wood core,
A wood chip made of small wood pieces is obtained by cutting and crushing and, if necessary, secondary crushing using a waste material chip or the like as a raw material. The shape of the wood chips is an arbitrary shape such as a chip shape, a flake shape, and a stick shape.

The wood chips are sorted as required, adjusted to a uniform size and shape, and dried to a water content of 6 to 15%.
Next, an adhesive is added to the wood chip and mixed. As the adhesive at this time, the same adhesive as the above-mentioned adhesive used for the softwood fiber can be used.

The wood chip to which the adhesive has been adhered is dried if necessary, and then conveyed to a forming device 4 (FIG. 3). (Forming hot pressing) The coniferous wood fibers and wood chips conveyed to the forming devices 3 and 4 by each line are:
As shown in FIG. 3, the three-layer mat is formed by laminating and depositing the front and back layers of the softwood fiber mats 1 and 1 and the wood chip mat 2 at the center.

After the three-layer mat is cut into an appropriate size by the cutting machine 5 and hot-pressed by the hot press device 6, the composite plate of the present invention is manufactured.

The forming of the wood chip by the forming device 4 may be performed while giving the orientation, so as to form an oriented wood chip layer.

Further, the composite board of the present invention is obtained by combining a softwood wood fiber board and a wood chipboard, which are separately manufactured in advance according to a conventional method, with a urea resin-based material such that the softwood wood fiber board is disposed on the front and back surfaces. It can also be manufactured by laminating via a phenolic resin-based or aqueous vinyl urethane resin-based adhesive, followed by pressure bonding by hot pressing.

When a composite board is obtained by bonding and integrating a softwood fiberboard and a wood chipboard as described above, the softwood having an arbitrary specific gravity is adjusted by adjusting the temperature, pressure or time of the heat and pressure in the manufacturing process. Wood fiberboard and wood chipboard can be used selectively. That is, softwood fiberboard having a specific gravity of 0.4 or less, 0.4 to 0.8
And those having an arbitrary specific gravity from the medium fiberboard and the hard fiberboard having a hardness of 0.8 or more can be used. Similarly, in the wood chip layer, a light wood chip board with a specific gravity of about 0.3,
It is possible to select and use a medium wood chipboard having a specific gravity of 0.4 to 0.8 and a hard wood chip layer of 0.8 to 1.05. According to this method, it is possible to easily manufacture a composite board in which the specific gravity of the wood fiber layers 1 and 1 obtained from softwood is set to be larger than the specific gravity of the wood chip layer 2.

The wood fiber layer 1 obtained from softwood is also used.
Since the thickness of the wood chip layer 2 can be freely adjusted, a composite plate having the strength and weight required as a composite plate can be easily obtained.

In the above, the three-layer composite board having the wood fiber layers 1 and 1 obtained from softwood on the front and back surfaces and having the wood chip layer 2 between them has been described.
A wood fiber layer 1 obtained from softwood is arranged only on the surface,
The present invention may be configured as a two-layer composite plate having a wood chip layer 1 on its back surface.

Hereinafter, a preferred embodiment of the present invention will be described in order to more specifically explain the present invention. (Manufacture of coniferous wood fiber) 1 radiata pine chip
The mixture was boiled at 60 ° C. and 7 kg / cm 2 for 5 minutes to perform degreasing and softening treatment. The chips were defibrated by a defibrator type refiner, and the obtained coniferous wood fibers were dried.

This coniferous wood fiber is charged into a blender, and 4% of the wood fiber content in the blender is calculated.
After adding and mixing a wax sizing agent and a 10% phenol resin adhesive, the mixture was conveyed to a forming apparatus. (Manufacture of wood chips) Raw radiata pine wood or waste material was charged into a flaker to obtain flake-shaped wood chips. After the wood chips were dried, they were sorted to obtain appropriate flake-shaped wood chips.

The wood chips were put into a continuous mixer, and 1% of a wax sizing agent and 8% of a phenol resin adhesive were added and mixed with the wood chips in the mixer, and then conveyed to a forming device. . (Mat formation / Hot pressing) The coniferous wood fiber and the wood chip conveyed as described above are placed on a screen conveyor from the downstream side in the conveying direction of the conveyer, from a conifer wood fiber forming device 3, a wood chip. Is formed on a screen conveyor by a square forming device installed in the order of the forming device 4 and the forming device 3 for coniferous wood fibers, and is stacked from the surface side in the order of conifer wood fiber mat / wood chip mat / conifer wood fiber mat. 3 consecutive
A layer mat was formed.

The continuous three-layer mat is cut into a predetermined size by a cutting machine 5 in a width and a length, and then inserted into a hot press 6 and hot-pressed at 200 ° C. for 5 minutes, each having a length of 5 m.
A composite board having an overall thickness of 25 mm and a size of 3 ′ × 6 ′ was obtained, in which a wood cutting layer 2 having a thickness of 15 mm was disposed between the front and back wood fiber layers 1 and 1 having a thickness of m.

The specific gravity of the wood fiber layers 1 and 1 in the obtained composite board was 0.7, the specific gravity of the wood chip layer 2 was 0.5, and the specific gravity of the entire composite board was 0.6. .

[0039]

According to the present invention, inexpensive wood chips are used,
By providing a wood fiber layer obtained from a softwood material exhibiting excellent surface smoothness and a white color on the surface or front and back surfaces of the wood chip layer, the cosmetic property is particularly good when applying a surface cosmetic treatment by painting, In addition, it is possible to provide an excellent composite board which solves problems such as expansion and shrinkage due to water absorption and moisture possessed by the wood chipboard through the restraining action of the wood fiber layer obtained from homogeneous softwood.

Further, since the thin and long coniferous wood fibers are entangled with each other to form a wood fiber layer, a composite board having excellent tensile strength and bending strength is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a composite board according to one embodiment of the present invention.

FIG. 2 is a view showing a manufacturing process of the composite board of the present invention.

FIG. 3 is an explanatory view schematically showing a line from forming to hot pressing in the manufacturing process of FIG. 2;

[Explanation of symbols]

 1 Wood fiber layer obtained from coniferous wood 2 Wood chipping layer

Claims (2)

[Claims] 1. A method in which a wood fiber layer is provided only on the front surface or on the front and back surfaces, and a wood chip layer is provided on the back surface of the front wood fiber layer or between the front and back wood fiber layers. A composite board characterized by being a wood fiber layer obtained from the above. 2. A wood fiber layer in which a wood fiber layer is provided only on the front surface or on the front and back surfaces and a wood chip layer is provided on the back surface of the front wood fiber layer or between the front and back wood fiber layers. A composite board, characterized by being a wood fiber layer obtained from (1), wherein the surface of the wood fiber layer has been subjected to a cosmetic treatment by painting.