JPH09100176A - Production of plaster board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce plaster boards of high interlaminar strength. SOLUTION: Plaster kneaded product for forming the outer layer is fed on the belt conveyer 4 to form the first layer 11, another foamed plaster kneaded product is cast on the first layer 11 to form the second layer, further plaster kneaded product for forming the outer layer is fed on the second layer to form the third layer 13. Jigs 21 and 22 are vertically stroked to allow the jig 21 to thrust through the second layer 12 to the half-way of the first layer 11, while the jig 22 is allowed to thrust through the third layer 13 to the half- way of the second layer 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gypsum board manufacturing method, and more particularly to a method of manufacturing a three-layer structure gypsum board.

[0002]

2. Description of the Related Art As shown in FIG. 3, a gypsum board having a three-layer structure has a pair of dense outer layers 1 and 3 with a lightweight intermediate layer 2 containing bubbles interposed therebetween.

As shown in FIG. 2, this gypsum board having a three-layer structure supplies a gypsum kneaded material for forming an outer layer onto a belt conveyor 4 to form a first layer 11, and the gypsum board is formed on the first layer 11. Supplying a gypsum kneaded material containing bubbles to form a second layer 12, and further supplying a gypsum kneaded material for forming an outer layer thereon to form a third layer 13, and then hardening the gypsum. Is manufactured by.

The gypsum kneaded product for forming the outer layer is obtained by kneading calcined gypsum, glass fiber and water in the mixer 5.

The gypsum kneaded material for forming the intermediate layer is a material in which bubbles are supplied to the kneaded material so as to contain air bubbles. This foam is obtained by stirring a mixed liquid of polyvinyl alcohol (PVA) and water together with air in the foaming machine 6 to foam.

Reference numerals 7, 8 and 9 in FIG. 2 denote plates (forming spatula) for pressing and kneading the kneaded material.

[0007]

However, according to the above-mentioned conventional method for producing a gypsum board, there is a problem that the produced gypsum board is likely to be peeled off between layers.

An object of the present invention is to provide a method for producing a gypsum board having a high bond strength between layers.

[0009]

The method for producing a gypsum board of the present invention is a method for producing a gypsum board having a three-layer structure in which a lightweight intermediate layer containing bubbles is interposed between a pair of dense outer layers. The gypsum kneaded product for forming the outer layer is supplied onto the conveyor to form the first layer, and the bubble-containing gypsum kneaded product for forming the intermediate layer is supplied onto the first layer to form the second layer. In a method for producing a gypsum board in which a gypsum kneaded product for forming an outer layer is supplied onto the second layer to form a third layer, after forming the second layer or the third layer, the upper side of the second layer or the third layer It is characterized in that the jig is put in and out so as to reach the layer below it to enhance the bondability between the layers.

The gypsum kneaded product preferably contains reinforcing fibers such as glass fibers. Further, this jig is preferably made of a rod-shaped body or a plate-shaped body.

In the method for producing gypsum board, the plaster kneaded products of the upper and lower layers are mixed in the vicinity of the layer interface by taking in and out the jig, and the bondability between the layers is enhanced.

In particular, when the gypsum kneaded material contains reinforcing fibers such as glass fibers, the fibers of the gypsum kneaded material of the upper layer are pushed into the lower layer by taking in and out the jig, and the fibers are spread over both the upper layer and the lower layer. Existing in the upper layer and the lower layer through this fiber.

In the present invention, the gypsum slurry contains gypsum, glass fibers having a fiber length of 3 mm or more, a water reducing agent and water, and the blending amount of the glass fibers is 100 gypsum in the slurry.
It is preferably 0.3 to 2.0 parts by weight with respect to parts by weight.

If the fiber length of the glass fiber is less than 3 mm, the reinforcing effect by the glass fiber cannot be sufficiently obtained. If the glass fiber is longer than 30 mm, the glass is likely to be clogged inside the mixer, and the slurry has poor fluidity, so that the surface of the plate has irregularities. Therefore, the length is preferably 30 mm or less. If the content of the glass fiber is less than 0.3 part by weight with respect to 100 parts by weight of gypsum, the reinforcing effect by the glass fiber cannot be sufficiently obtained, and the glass tends to be damaged during processing. It worsens and the reinforcing effect reaches the ceiling.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a cross-sectional view for explaining an embodiment method, in which a first jig 21 is provided in the vicinity of a molding spatula 8 so that a second layer can be projected from above, and a third jig is provided. A second jig 22 is provided near the forming spatula 9 so that the layer can be projected from above.

The jigs 21 and 22 are made of a rod-shaped body or a plate-shaped body, and are vertically moved by an appropriate reciprocating drive device such as a solenoid, an air cylinder, and a motor rotary crank mechanism.
The jig 21 penetrates the second layer 12 and is stroked to reach the middle of the first layer 11, and the jig 22 penetrates the third layer 13 and is stroked to reach the middle of the second layer 12. .

The depth of penetration of the jig 21 or 22 into the first layer 11 or the second layer 12 is preferably 1 to 4 mm. In the belt feeding direction, the jig 21 or 22
It is preferable that the distance between the points is 5 to 100 mm.

When the jigs 21 and 22 are rod-shaped bodies, the diameter of the rod-shaped bodies is preferably about 2 to 10 mm. Jigs 21 and 2
When 2 is a plate, the plate has a thickness of 0.5 to 10
mm, and the width is preferably about 1 to 10 mm.

When the rod-shaped bodies are used, the distance between the rod-shaped bodies is 8 to 30 mm, and in the case of a gypsum board having a width of 600 mm,
It is preferable to use about 75 to 20 in total. When using a plate, the total is 5 for a gypsum board with a width of 600 mm
It is preferable to use ~ 30 plate-shaped bodies. The orientation of the plate surface of the plate-shaped body is arbitrary.

The jigs 21 and 22 are most preferably made of stainless steel, fluororesin, or polyethylene, which does not easily adhere to the gypsum-kneaded material, but brass, copper, nickel, synthetic resin, or the like, which does not easily corrode, may be used. The other configuration of FIG. 1 is the same as that of FIG. 2, and the same reference numerals are given to the same portions and the description thereof will be omitted.

The jig 21 mixes the interface between the first layer 11 and the second layer 12, and the jig 22 mixes the interface between the second layer 12 and the third layer 13. The bondability can be enhanced. Also, each layer 11, 1
Glass fibers are mixed in 2 and 13, and the second layer 12
Of the glass fibers therein, those existing near the interface with the first layer 11 are pushed by the jig 21 and are pushed into the first layer 11 to be present across both layers 11 and 12. . In addition, the second layer 12 out of the glass fibers in the third layer 13
What was present in the vicinity of the interface with and is pushed by the jig 22 and pushed into the second layer 12 so as to be present over both layers 12 and 13. As a result, between the layers 11 and 12,
And the bond between the layers 12, 13 is further enhanced.

When the jig 21 penetrates the second layer 12 and is pushed into the first layer 11, the plaster of the first layer 11 has not reached the end. Of course, the second layer 1 just formed
No. 2 has sufficient fluidity. Therefore, by moving the jig 21 up and down so as to reach the first layer 11 from the second layer 12, the vicinity of the interface between both layers 11 and 12 is sufficiently mixed, and the trace of pulling out the jig 21 remains. It does not remain on the second layer 12. Of course, even if the first layer is pierced by the jig 21, it does not cause cracks or the like.

The second layer 12 and the third layer 1 through the third layer 13
The same applies when the interface with 3 is pierced by the jig 22.

The second jig 22 is stroked so as to reach only the second layer 12 because the first layer 11 which has reached the installation position of the second jig 22 has already been considerably hardened. This is because it is too hard to be struck by the jig 22. However, if the setting of the first layer 11 has not been completed even at the set positions of the second jig 22, for example, by adding a setting retarder to the first layer 11, the second jig 22 is The stroke may be continued until the first layer 11 is reached. In this case, the first jig 21 may be omitted and only the second jig 22 may be used. However, in the normal case, it is preferable to use both the jigs 21 and 22 as shown in FIG.

[0025]

EXAMPLE A specific manufacturing example will be described below.

Example 1 Width 600 mm, thickness 60 mm, outer layer thickness 5 m each
A gypsum board having a thickness of m and an intermediate layer thickness of 50 mm was manufactured as shown in FIG. 1 using the following materials. The following composition is the composition amount per 2.4 m of gypsum board.

Composition of outer layer: 10 kg of gypsum, 9 kg of water, 50 g of glass fiber Composition of intermediate layer: 10 kg of gypsum, 8 kg of water, 1 glass fiber
00g, PVA10g Belt conveyor feed rate: 1.8 m / min Jigs 21, 22: 30 mm stainless steel rod with a diameter of 5 mm
20 conveyors arranged at intervals with a width direction of 18 times / min
The stroke was made by the air cylinder. The penetration depth of the jig 21 into the first layer 11 was 2 mm, and the penetration depth of the jig 22 into the second layer 12 was 3 mm.

As a result, the peel strength between layers is 4.3 k on average.
It was possible to produce g / cm ² gypsum board.

Comparative Example 1 A gypsum board was manufactured in the same manner as in Example 1 except that the jigs 21 and 22 were stopped. The peel strength between the layers of the obtained gypsum board was 2.1 kg / cm ^{2 on} average.

[0030]

As described above, according to the gypsum board manufacturing method of the present invention, it is possible to efficiently manufacture a gypsum board having a very high bonding strength between layers.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a method of manufacturing a gypsum board according to an example.

FIG. 2 is a cross-sectional view showing a method for manufacturing a gypsum board according to a conventional example.

FIG. 3 is a cross-sectional view of a gypsum board.

[Explanation of symbols]

 1,3 Outer layer 2 Intermediate layer 5 Mixer 6 Foaming machine 10 Heater 11 First layer 12 Second layer 13 Third layer 21 First jig 22 Second jig

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B28B 5/02 B28B 5/02

Claims (3)

[Claims] 1. A method for producing a gypsum board having a three-layer structure in which a lightweight intermediate layer containing air bubbles is interposed between a pair of dense outer layers, wherein a plaster kneaded product for forming the outer layer is placed on a conveyor. To form a first layer, the bubble-containing gypsum kneaded product for forming an intermediate layer is supplied onto the first layer to form a second layer, and the gypsum kneaded product for forming an outer layer is further supplied onto the second layer. In the method for producing a gypsum board as a third layer, after forming the second layer or the third layer, the jig is reached from above the second layer or the third layer to a layer below the jig. A method for manufacturing a gypsum board, characterized in that it is put in and out to enhance the bondability between layers. 2. The gypsum board according to claim 1, wherein each of the gypsum kneaded products contains a reinforcing fiber, and the reinforcing fiber enters the adjacent layer through a layer interface when the jig is taken in and out. Manufacturing method. 3. The method for manufacturing a gypsum board according to claim 1, wherein the jig is a rod-shaped body or a plate-shaped body.