JPH08244020A - Production of gypsum particle board - Google Patents

Abstract

PURPOSE: To simply produce a gypsum particle board suitable as an interior material. CONSTITUTION: Water is added to ground wood pieces to bond a gypsum hemihydrate powder (g) to the wood pieces and, thereafter, a mat 1A is formed on a horizontally leveled flowable gypsum aq. liquid gw to be temporarily pressed and a flowable gupsum aq. liquid gw is allowed flow along the upper surface of the mat 1A to be horizontally leveled to be cured.

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 gypsum particle board suitable for interior materials such as floor materials, walls and ceilings.

[0002]

2. Description of the Related Art Generally, a particle board formed by molding a wood piece into a plate shape with an adhesive such as a urea resin, a phenol resin, or a melamine resin, or a wood chip cement board formed by molding a wood piece into a plate shape using cement as a binder is known. ing. In addition, gypsum board containing 1 to 10% of natural fiber or chemical fiber as a reinforcing material is commercially available.

[0003]

However, the above-mentioned particle board has small specific gravity and high strength and is excellent in workability, but has a drawback that it is inferior in fire resistance and dimensional stability. Further, although the wood chip cement board and the gypsum board are excellent in fireproofness, they have drawbacks that they have large specific gravity, low strength, and low workability.

It has been attempted to form a wood piece into a plate shape using gypsum as a binder, but there is a problem that the adhesion between the gypsum and the wood piece is low and the strength and water resistance are lower than those of other competing products. is there. That is, gypsum is obtained by adding more water than water to be crystal water to hemihydrate gypsum to change it to dihydrate gypsum, but usually a mixed solution of hemihydrate gypsum and water is in a fluid state, When the wood chips are mixed with the mixed solution, they are hardened in a dumpling shape, so that it is difficult to uniformly mix them. In particular, it is extremely difficult to process the edges.

The present invention has been made in view of the above problems, and it is possible to continuously manufacture gypsum particleboard, which is a composite material of gypsum and wood chips, which is suitable as an interior material, regardless of size. A method for manufacturing a gypsum particle board is provided.

[0006]

According to the present invention, hemihydrate gypsum powder is adhered by adding water to a hemihydrate gypsum powder after flowing a fluid gypsum water solution in a flowing state and leveling it horizontally. By classifying the ground crushed wood pieces, hemihydrate gypsum powder is deposited on the surface layer, and at the same time, a large crushed wood piece to a small crushed wood piece are sequentially deposited on the core layer toward the surface layer to form a mat. After temporary pressing, a fluid gypsum water solution is flowed on it to be leveled and hardened.

[0007]

In the present invention, water is added to crushed wood pieces to deposit hemihydrate gypsum powder, and then classified on a horizontally leveled fluid gypsum water solution to form a mat. After temporarily holding the mat, flow a fluid gypsum water solution on it to level it horizontally and harden it to continuously and easily produce plaster particle boards suitable for interior materials regardless of size. can do.

In this case, by mixing a sizing agent or a resin in the gypsum aqueous solution, the strength deterioration of the gypsum layer due to the infiltration of water can be suppressed, so that the strength can be further improved.

[0009]

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. This gypsum particle board 1
The gypsum layer 2 made of gypsum dihydrate G is formed on the surface layer, and the wood piece layer 3 is formed on the core layer in order from the large crushed wood piece C to the small crushed wood piece C toward the surface layer.

The gypsum particle board 1 has the advantage that it has small expansion and contraction and excellent dimensional stability as well as excellent fire resistance because the plaster layer 2 having a high density is formed on the surface layer. That is, the temperature does not exceed 100 ° C. until the water of crystallization contained in gypsum dihydrate is dehydrated, and a certain time can be secured before firing. Moreover, since the wood piece layer 3 that is light and has high rigidity is formed on the core layer, the specific gravity is low, the strength is high, the nail holding power is high, and the workability and construction at the site are excellent, and the heat insulating property is high. Good sound insulation. As a result, interior materials such as
Suitable for flooring, walls and ceilings.

In order to manufacture such a gypsum particle board 1, wood, for example, lauan is first cut with a chipper to a thickness of 0.5 mm and a length of 50 mm, and then,
Crush with a hammer mill. In addition, some large pieces of wood
Grind with a Pearlman mill. These crushed wood pieces have a water content of 100 to 13 without undergoing a drying process.
Adjust by adding water to 0%. And hemihydrate gypsum powder is made to adhere to these crushed wood pieces.

On the other hand, water is added to the hemihydrate gypsum powder to prepare a fluid gypsum aqueous solution, which is flowed on a caul plate and leveled horizontally, and then the above-mentioned crushed wood pieces are classified on the gypsum aqueous solution. That is, as shown in FIG. 2, a mixture of crushed wood chips C _{g to} which hemihydrate gypsum powder g is attached and hemihydrate gypsum powder g is used as a hopper 1.
1, when air is ejected from the blowing device 13 in the front-back direction (left-right direction in FIG. 2), a large crushed wood piece C _g containing water and to which hemihydrate gypsum powder g is adhered is affected by the air. A small crushed piece of wood C containing water and containing hemihydrate gypsum powder g
_g is blown away, and hemihydrate gypsum powder g is blown away further.

Here, the caul plate 12 is moved forward (see the arrow in FIG. 2).
Direction), with respect to the moving direction of the caul plate 12
In the rear, gypsum water liquid g_WHemihydrate gypsum powder deposited on top
The gypsum hemihydrate g
Crushed wood chips C attached_gOf which, a small piece of wood C_gTo large
Wood piece C_gWill be deposited in order. And blow
Contrary to the above, when passing over the feeding device 13, a large piece of wood
C_g, A small piece of wood C_g, Hemihydrate gypsum powder g are deposited in this order
Will be. As a result, the flow evenly distributed on the caul plate 12
Dynamic gypsum water solution g_WFirst, hemihydrate gypsum powder g was deposited.
Then small crushed wood chips C_gFrom the core layer
Therefore, a large crushed wood piece C_gAfter being deposited in order,
Crushed wood chips C_gPowder from the bottom to the surface
Ground wood C _gAre sequentially deposited, and then hemihydrate on the surface again
The mat 1A is formed by depositing plaster powder g.
It

Then, after the mat 1A is temporarily pressed, a fluid gypsum water solution g _W is poured on the surface layer, that is, the hemihydrate gypsum powder g, and is leveled and hardened. During this time, hemihydrate gypsum powder g uptake excessive water moisture and fluidized gypsum water solution g _W contained in the pulverized wood chips C _g, it changes to the gypsum G with fluidized gypsum water solution g _W, gypsum The particle board 1 will be manufactured.

As a result, the gypsum particle board 1 which is excellent in fireproofness, dimensional stability, workability, and is light and has high strength can be continuously and easily manufactured regardless of its size.

In particular, the gypsum water solution g _W forms a surface layer to obtain a dense and smooth surface, and when a corrugated pattern is formed on the caul plate 12, a sharp and beautiful surface plaster particle board having the concavo-convex pattern is formed. 1 can be manufactured.

When a sizing agent or resin is mixed in the gypsum layer 2, the resin or sizing agent described above diffuses into the crystal boundaries of the gypsum G in a three-dimensional network, and the water content of the gypsum layer 2 is reduced. It is possible to suppress the strength deterioration due to infiltration and further improve the strength. Specifically, a sizing agent equivalent to 0.1 to 4% of the hemihydrate gypsum powder g, for example, paraffin emulsion is added to the fluid gypsum aqueous solution g _W , or 0.5 g of the hemihydrate gypsum powder g is added. Water-soluble EVA (ethylene-vinyl acetate copolymer) equivalent to 10%, PAE
By adding (polyacrylic acid ester) or SBR (styrene / butadiene rubber), it is possible to increase the strength while suppressing the cost increase. In this case, the paraffin emulsion having smaller particles has better dispersibility, and the strength reduction can be suppressed with a small addition amount, and the resin is preferably SBR from the viewpoint of water resistance.

By the way, in the above-mentioned embodiment, the hemihydrate gypsum powder g and the crushed wood pieces C _g to which the hemihydrate gypsum powder g is adhered are classified by using the wind force, but gravity sorting is used. You can also For example, as shown in FIG. 3, hemihydrate gypsum powder g and hemihydrate gypsum powder g from the hopper 11
It is also possible to form the mat 1A by dropping the crushed wood chips C _g to which is attached to the inclined plate 15 via the guide plate 14 and utilizing the difference in repulsive force. That is, the crushed wood pieces C _g that have fallen on the inclined plate 15 bounce up and fall far away, while the hemihydrate gypsum powder g slides along the inclined plate 15 and falls right below the lower edge thereof. Therefore, by flowing the fluid gypsum water solution g _W on the caul plate 12 and leveling it horizontally, the caul plate 12 is moved to move the caul plate 12 to the rear side with respect to the inclined plate 15. Hemihydrate gypsum powder g is deposited at a position just below the lower end of the, and small wood pieces C _g and large wood pieces C _g are deposited in this order on the hemihydrate gypsum powder g that was previously deposited as the caul plate 12 moves. Further, when passing over the other inclined plate 15, contrary to the above, large pieces of wood C _g , small pieces of wood C _g and hemihydrate gypsum powder g are deposited in this order.

Also in this case, the hemihydrate gypsum powder g is deposited on the surface layer on the fluid gypsum water solution g _W leveled on the caul plate 12, and the crushed wood pieces are large on the core layer toward the surface layer. The small crushed wood pieces C _g are sequentially deposited from C _g to form the mat 1A. Hereinafter, as described above, after the mat 1A is temporarily pressed, a fluid gypsum water solution g _W is poured on the surface hemihydrate gypsum powder g to level it horizontally.
The gypsum particle board 1 can be manufactured by hardening.

In addition to this, classification by sieving may be used, or these may be used in combination.

[0022]

As described above, in the present invention, water is added to crushed wood chips to attach hemihydrate gypsum powder, and then the mat is prepared by classifying the gypsum powder on a horizontally level fluid gypsum water solution. Formed, then, after temporarily pressing the mat, flow a fluid gypsum water solution on it to level it horizontally, and continuously harden the gypsum particle board suitable as an interior material by curing, regardless of size, And it can be easily manufactured.

[Brief description of drawings]

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

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

FIG. 3 is an explanatory view showing another classification step when manufacturing the gypsum particle board of the present invention.

[Explanation of symbols]

1 gypsum particle board 1A mat 2 gypsum layer 3 wood piece layer 11 hopper 12 call board 13 blowing device 14 guide plate 15 inclined plate G gypsum (dihydrate gypsum) g hemihydrate gypsum powder C crushed wood pieces C _g hemihydrate gypsum powder is attached Crushed wood pieces g _W gypsum water solution

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area E04C 2/26 E04C 2/26 P

Claims (3)

[Claims] 1. A fluid gypsum water solution in which water is added to hemihydrate gypsum powder is poured and leveled horizontally, and then water is added to classify crushed wood pieces to which hemihydrate gypsum powder is adhered. , A hemihydrate gypsum powder is deposited on the surface layer, and from the large crushed wood pieces to small crushed wood pieces are sequentially deposited on the core layer toward the surface layer to form a mat, and then the mat is temporarily pressed, and then the mat is temporarily pressed. A method for producing a gypsum particle board, which comprises flowing a liquid gypsum water solution, leveling the solution horizontally, and curing the solution. 2. The method for producing gypsum particle board according to claim 1, wherein a sizing agent is mixed in the gypsum aqueous solution. 3. The method for producing gypsum particle board according to claim 1, wherein a resin is mixed in the gypsum water solution.