JP2557350Y2 - Board material - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate made of medium-density fiberboard used for a wide range of applications such as wall materials, floor materials, fitting members, construction members, furniture members and the like.

[0002]

2. Description of the Related Art Medium specific gravity fiberboard has a specific gravity of 0.4 to 0.8.
Although it is relatively lightweight, it has excellent strength properties and good workability, so it is possible to apply optional makeup to the surface as necessary, and to make wall surfaces, floor materials, fittings, construction members,
Widely used for various applications such as furniture members.

In the case of the medium specific gravity fiberboard, for example, when a dry method is used, an adhesive is applied to wood fibers obtained by defibrating wood, and this is formed and temporarily pressed to form a fiber mat.
This fiber mat is obtained by cutting the fiber mat into a fixed size to form a fixed size mat, and then heating and pressing.

[0004]

Although the medium specific gravity fiberboard generally has satisfactory overall performance as described above, it is desired to further improve various physical properties while maintaining its light weight. I have.

[0005] For example, when used in an application in which a large load acts on the surface, it is desired to further increase the bending strength and minimize the amount of deflection change with respect to the load.

Further, since the medium specific gravity fiber board is relatively soft, it has a drawback that expansion and contraction are likely to occur due to a change in water content. Therefore, it is desired to suppress this and improve dimensional stability.

[0007] Hard fiber boards, generally called hard boards, are widely industrially produced, are high specific gravity fiber boards having a specific gravity of 0.8 or more, and are excellent in bending strength and dimensional stability. Light weight is impaired, and there is a problem in workability and handling.

[0008]

SUMMARY OF THE INVENTION Accordingly, the present invention is to provide a novel plate material which is a plate material having a medium specific gravity fiber board as a base material, but whose physical properties are enhanced, and which is suitably used for a wide range of applications. Aim.

That is, the plate material according to the present invention has an overall specific gravity.
0.4-0.8 medium specific gravity fiberboard,
And a hard layer with a specific gravity of 0.8 to 1.4 inside
It is characterized by becoming.

[0010]

It is preferable that the inner hard layer has a greater thickness than the hard layers on the front and back sides.

A plurality of internal hard layers can be provided as necessary.

A non-permeable layer made of synthetic resin or the like can be formed on the surface of the plate, if necessary.

[0014]

[Function] Since it is a plate made of a medium-density fiberboard having a specific gravity of 0.4 to 0.8, it is lightweight and excellent in workability and handling.

The plate material is reinforced by the hard layers having a specific gravity of 0.8 to 1.4 on the front and back portions and inside, and the dimensional stability is improved.

[0016]

FIG. 1 shows the structure of a plate material according to an embodiment of the present invention. The medium specific gravity fiberboard has a hard layer of a front hard layer 1, a back hard layer 2, and a single internal hard layer 3. Consisting of The hard layers 1 and 2 on the front and back portions can be exposed on the front and back surfaces of the plate material as shown.

The overall specific gravity of the medium specific gravity fiberboard is 0.4 to 0.8.
Where each hard layer has a specific gravity of 0.8 to 1.4.

As described above, in the medium specific gravity fiberboard, a hard layer having a high specific gravity, and excellent in tensile strength and compressive strength is formed on the front and back portions and inside of the board, so that the bending strength is large while being lightweight. The amount of deflection change with respect to load is small.

The thickness of each hard layer is generally 0.3 to 5 mm. However, by making the thickness of the inner hard layer 3 larger than that of the front and back hard layers 1 and 2, the strength properties of the plate material are further improved. You.

By forming a hard layer having a high specific gravity and a water-impermeable property on the front and back portions, absorption of water from the front and back surfaces is substantially prevented. In addition, since the inner hard layer acts like a reinforcing bar, the occurrence of expansion and contraction due to a change in water content is suppressed. As a result, a plate having extremely excellent dimensional stability can be obtained.

A plate having such a configuration can be manufactured as follows.

That is, in general, a medium-density fiberboard is prepared by, for example, adding a bonding agent or the like in a manufacturing process of a wood fiberboard by a dry method and depositing the dried woodfiber on a screen conveyor by a forming apparatus. The wood fiber mat is temporarily pressed to obtain a wood fiber mat, which is then cut to a fixed size to obtain a fixed-length wood fiber mat, which is obtained by heating and pressing the wood fiber mat. By increasing the amount of the adhesive to be added or increasing the water content of the wood fiber, the thickness of the hard layer on the front and back sides is increased. In addition, water is applied to the upper or lower surface of the fixed-length wood fiber mat, or a water-retainable sheet such as nonwoven fabric, paper, or cloth is placed on the upper or lower surface of the wood fiber mat. When heating is performed in this state, the heating and pressing are performed in a state where the water content of the front and back portions is increased, so that the thickness of the hard layer increases. In this way, a medium-density fiberboard having a hard layer having a predetermined thickness on the front and back sides is obtained.

In the obtained medium specific gravity fiber board, a low specific gravity thin surface layer is formed by pre-curing of an adhesive at the time of heating and pressing, and if necessary, sanding is performed to remove the low specific gravity thin surface layer. The layer is exposed on both sides.

The medium-density fiberboard thus obtained is laminated with an adhesive, and two sheets are laminated by pressure-bonding to obtain a medium-density fiberboard having a hard layer on each of the front and back and inside. A plate according to the present invention as shown in FIG. 1 is obtained.

In the plate material obtained by the above method,
Since the inner hard layer is formed as a composite of the laminated back hard layer of the upper middle specific gravity fiber board and the front hard layer of the lower middle specific gravity fiber board, the inner hard layer is more rigid than the front and back hard layers of the plate material. Inevitably, the layer thickness is increased, and a material having favorable strength is obtained.

The internal hard layer 3 can be formed in a plurality of layers as required. FIG. 2 shows an example of a configuration in which three internal hard layers are formed.

As the plate material having a plurality of internal hard layers 3, a plurality of medium specific gravity fiber boards having hard layers on the front and back manufactured by the method described above are used, and in the embodiment of FIG.
They can be manufactured by laminating and bonding them.

[0028]

[Effect of the Invention] Since the hard layers having a high specific gravity are disposed on the front and back portions and inside of the medium specific gravity fiberboard, a plate material which is lightweight and has excellent dimensional stability and strength characteristics is provided.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a plate according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a plate according to another embodiment of the present invention;

[Explanation of symbols]

 Reference Signs List 1 front hard layer 2 back hard layer 3 internal hard layer

Claims (2)

(57) [Scope of request for utility model registration] 1. A medium-density fiberboard having an overall specific gravity of 0.4 to 0.8.
And the specific gravity of 0.8-
A plate material comprising the hard layer of 1.4. 2. The plate according to claim 1, wherein the inner hard layer is formed to be thicker than the hard layers on the front and back sides.