JP3271687B2 - Gypsum particle board and its manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gypsum particle board suitable for an interior material such as a floor material, a wall or a ceiling, and a method for producing the same.

[0002]

2. Description of the Related Art In general, there is known a particle board in which a piece of wood is formed into a plate using an adhesive such as a urea resin, a phenol resin, or a melamine resin, and a cement board in which a piece of wood is formed into a plate using cement as a binder. ing. Gypsum boards containing about 1 to 10% of natural fibers or chemical fibers as reinforcing materials are also commercially available.

[0003]

However, the above-mentioned particle board has a low specific gravity, a high strength, and is excellent in workability, but has a disadvantage that it is inferior in fire resistance and dimensional stability. Although the wood chip cement board is excellent in fire resistance and dimensional stability, it has disadvantages of high specific gravity, low strength, and low workability. Further, gypsum board has excellent fire resistance, dimensional stability, workability, and low specific gravity, but has a drawback of low strength.

It has been attempted to form a piece of wood into a plate using gypsum as a binder. However, there is a problem in that the adhesion between the gypsum and the piece of wood is low, and the strength and water resistance are lower than other competitive products. is there. That is, gypsum is obtained by adding more water than water that becomes crystallization water to hemihydrate gypsum and changing it into gypsum, but the mixture of hemihydrate gypsum and water is usually fluid, When wood chips are mixed with the mixed solution, it is difficult to uniformly mix both as a result of hardening into a dumpling shape. In particular, it is extremely difficult to treat the edge.

The present invention has been made in view of the above problems, and provides a gypsum particle board which is a composite material of gypsum and a piece of wood which is suitable as an interior material. It is intended to provide a method for producing a gypsum particle board which can be produced continuously without using the same.

[0006]

The gypsum particle board of the present invention is characterized in that wood pieces are uniformly mixed in a gypsum layer made of gypsum dihydrate.

The method for producing gypsum particle board of the present invention is characterized in that wood and dihydrate gypsum are crushed, high-temperature steam is supplied to the crushed wood pieces and gypsum and mixed with stirring.
Water is supplied to the mixed wood chips and hemihydrate gypsum, and the mixture is cooled and pressed into a plate shape.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a gypsum particle board 1 of the present invention.
Is a plate formed by uniformly mixing wood chips C in a gypsum layer 2 made of dihydrate gypsum G.

This gypsum particle board 1 has the advantages of gypsum and wood. That is, gypsum having a high density has a small expansion and contraction, is excellent in dimensional stability, and is also excellent in fire resistance. In other words, the temperature does not exceed 100 ° C. until the water of crystallization contained in the gypsum dihydrate G is dehydrated, and a certain time can be secured before the burning. In addition to being light and having high rigidity, the wood has low specific gravity, high strength, high nail holding power, excellent processing and construction on site, and good heat insulation and sound insulation. As a result, it is suitable for interior materials, for example, floor materials, walls, and ceilings.

In order to manufacture such a gypsum particle board 1, a gypsum (dihydrate gypsum) G and a wood W are crushed by a crusher C.
r (see FIG. 2 (a)), the mixture is formed by stirring and mixing with the mixer M while supplying high-temperature steam of 80 ° C. or more to the ground gypsum G and the wood chips C (FIG. 2 (a)). b)). At this time, gypsum (dihydrate gypsum) G
In water, the water of crystallization is separated by hot steam and turns into gypsum hemihydrate. Next, water is supplied to the mixture of the gypsum (semihydrate gypsum) and the wood chips C, and the mixture is cooled and molded into a plate shape via the molding device F (see FIG. 2C). As a result, the gypsum hemihydrate gypsum takes in the separated water and changes again into gypsum gypsum G, so that the gypsum particle board 1 in which the wood chips C are uniformly mixed in the gypsum G can be manufactured.

As a result, the gypsum particle board 1 having excellent properties of fire protection, dimensional stability, workability, lightness and high strength can be manufactured continuously and easily regardless of the size.

In this case, since waste gypsum board can be used as the gypsum G and waste wood can be used as the wood W, waste which had to rely on landfill or incineration can be recycled. Can be used.

If a sizing agent or a resin is mixed in the gypsum layer 2, the sizing agent or the resin described above is diffused in a three-dimensional network at the crystal boundary of the gypsum G, and the water infiltration of the gypsum layer 2 is prevented. The strength can be prevented from deteriorating, and the strength can be further improved. Specifically, when a mixture of hemihydrate gypsum and wood chip C is subjected to pressure molding, a sizing agent corresponding to 0.1 to 4% of gypsum, for example, a paraffin emulsion is added to water for cooling the mixture. Of gypsum.
Water-soluble EVA (ethylene-vinyl acetate copolymer), PAE (polyacrylate) equivalent to 5 to 10%
By adding SBR (styrene / butadiene rubber), the strength can be increased while suppressing the increase in cost. In this case, the paraffin emulsion having smaller particles has good dispersibility, can suppress the strength reduction with a small amount of addition, and the resin is preferably SBR from the viewpoint of water resistance.

[0015]

As described above, in the gypsum particle board according to the first aspect, the strength of the gypsum particle board is higher than that of a wood chip cement board or a gypsum board due to the fact that wood chips are uniformly mixed in the gypsum layer made of gypsum dihydrate. In addition to the large particle size, it has higher dimensional stability than particle board and excellent fire protection. In addition, heat insulation and sound insulation are good, and on-site processing and construction are easy.

In the method for producing gypsum particle board according to the second aspect of the present invention, the wood and the dihydrate gypsum are pulverized, and high-temperature steam is supplied to the pulverized wood pieces and the dihydrate gypsum, followed by stirring and mixing. By supplying water to the wood piece and the hemihydrate gypsum and cooling it into a plate while pressing it, a gypsum particle board in which wood pieces are uniformly mixed in a gypsum layer made of gypsum dihydrate is continuous regardless of size And can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gypsum particle board of the present invention.

FIG. 2 is an explanatory view showing a manufacturing process of the gypsum particle board of the present invention.

[Explanation of symbols]

 1 gypsum particle board 2 gypsum layer C ground wood chips G gypsum (dihydrate gypsum)

Claims (2)

(57) [Claims] 1. A gypsum particle board characterized in that wood pieces are uniformly mixed in a gypsum layer made of gypsum dihydrate. 2. A grinding the wood and gypsum was ground
Gypsum particles characterized in that high-temperature steam is supplied to a piece of wood and gypsum and mixed with stirring, and then water is supplied to the mixed piece of wood and gypsum hemihydrate to form a plate while being cooled and pressed. Board manufacturing method.