JPH09286011A - Manufacture of inorganic plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve productivity by preventing a filter medium from clogging so as to smoothly dewater excessive water. SOLUTION: In a method for manufacturing an inorganic plate, a water base slurry 4 having a cement as a main component is made to flow into a mold and molded by press molding so as to remove excessive water included in the water base slurry 4 through a filter medium 3. After inorganic aggregates 5 such as perlite, sepiolite, and pebble and others are laid on the filter medium 3 as a filter aid, the water base slurry 4 is made to flow in, and dewatering and molding are performed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an inorganic plate, and more particularly to a method for manufacturing an inorganic plate useful for building boards and the like.

[0002]

2. Description of the Related Art Conventionally, as a method for manufacturing an inorganic plate,
Along with the papermaking method and the extrusion method, a method has been adopted in which an aqueous slurry containing cement as a main component is poured into a mold, and the excess water contained in the aqueous slurry is removed while press-forming this aqueous slurry. Then, if necessary, an inorganic plate is manufactured by subjecting a sheet formed from the above-mentioned aqueous slurry in a green plate shape to autoclave curing or steam curing.

[0003]

However, in the case where the aqueous slurry is poured into the mold and the excess water is removed by press molding as described above, the excess water is dehydrated through the filter medium, but the filter medium It tends to be clogged, and the time required for press molding to remove excess water tends to be long, and increasing the press molding pressure does not lead to a reduction in the time required for press molding, and there is a limit. It was a thing. In addition, it takes a long time to demold the green plate-shaped product after pouring the aqueous slurry and press-molding, which is not good in terms of productivity in any case.

The present invention has been made in view of the points described above, and an object thereof is to smoothly dehydrate excess water to improve productivity.

[0005]

In order to solve the above-mentioned problems, the method for producing an inorganic plate of the present invention is such that an aqueous slurry containing cement as a main component is poured into a mold and press-formed to be contained in the aqueous slurry. In the method for producing an inorganic plate for removing excess water that has passed through a filter medium, pearlite,
It is characterized in that an inorganic aggregate such as sepiolite or pebbles is laid as a filter aid on the filter material, and then an aqueous slurry is poured in to perform dehydration molding. By pouring the aqueous slurry after laying the inorganic aggregate on the filter material as a filter aid, it is possible to prevent clogging of the filter material and dehydrate the excess water of the aqueous slurry, which is necessary for dehydration by press molding. Time can be shortened and productivity can be improved.

It is also preferable that the filter aid is a lightweight inorganic aggregate such as perlite.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The lower mold 1 is in the shape of a container, and has a large number of water drainage holes 2 at the bottom. The bottom of the lower mold 1 is covered with a filter material 3 that allows only water to pass through. As the filter material 3, there is a material such as felt, but any material that allows water to pass through may be used. The aqueous slurry 4 is mainly composed of cement as a raw material,
If necessary, an aggregate, a reinforcing agent and a fiber component are mixed, and water is mixed to form a slurry. Before the aqueous slurry 4 is poured into the lower mold 1, an inorganic aggregate 5 such as perlite, sepiolite, or pebbles is laid as a filter aid on the filter material 3. As the inorganic aggregate 5, a lightweight one such as perlite is preferable. After the inorganic aggregate 5 is laid, the aqueous slurry 4 is poured into the lower mold 1 and pressed by the press board 6, and the surplus water is discharged through the filtering material 3 and the water draining hole 2 so that the aqueous The slurry 4 is dehydrated. At this time, since the inorganic aggregate 5 is laid on the filter material 3 as a filter aid, the filter material 3 can be smoothly removed without clogging, and the time required for pressing can be shortened to improve productivity. Can be improved. Excess water is dehydrated from the aqueous slurry 4 to form a green plate-like material called a green sheet, which is cured by autoclave curing or steam curing to obtain a cured inorganic plate. At this time, if a lightweight material such as pearlite is used as the inorganic aggregate 5, the weight of the inorganic plate can be reduced, and if it is porous such as pearlite, the inorganic plate can have a heat insulating property. It is also preferable that the aqueous slurry 4 is cured by autoclave curing to form tobermorite. That is, when the autoclave is cured, silica and calcium in the cement are bonded to each other to form a strong tobermorite gel or quasicrystal. When the tobermorite is formed in this way, a strong inorganic plate can be formed.

[0008]

[Examples] In Examples 1 and 2, cement, fly ash, and silica stone were each used as 100 to form a matrix.
It is used in an amount of 100 parts by weight, 100 parts by weight, and 40 parts by weight, and NBKP pulp is dry defibrated at a ratio of 15 parts by weight and a concentration of 20 parts by adding water and kneading
A wt% aqueous slurry was obtained. In Examples 3 and 4, cement, fly ash, and
Granulated blast furnace slag was used in an amount of 100 parts by weight, and NBKP pulp was added thereto at a ratio of 20 parts by weight, and water was added to knead the mixture to obtain an aqueous slurry having a concentration of 20 wt%. As shown in FIG. 1, the aqueous slurries of Examples 1 to 4 were put into a lower mold so that the thickness after pressing was 15 mm, and dehydrated from the filter material on the lower surface. This filter material is a filter cloth made of cloth. In the case of Examples 1 to 4, after perlite (manufactured by Mitsui Kinzoku Co., Ltd.) was filled to a thickness of 5 mm on the filter material,
Fill with aqueous slurry, then press pressure 3-5 MPa
Was dehydrated and press molded. In addition, it is better to bond perlite with an acrylic resin or the like for fixing. In Examples 1 and 2, the molded body press-molded as described above was heated at a temperature of 8
After curing for 10 hours in an atmosphere of 0 ° C. and 100% humidity, a cured product was obtained by curing in an autoclave at a temperature of 170 ° C. for 10 hours. In Examples 3 and 4, the molded body was heated to a temperature of 80.
A cured product was obtained by curing for 100 hours in an atmosphere of ℃ and 100% humidity. Then, each cured product was dried at a temperature of 60 ° C. All of the above Examples 1 to 4 are good cured products,
Moreover, it was a composite having a pearlite heat insulating layer on the back surface.

The dewatering time by the press of Examples 1 to 4 is shown in Table 1 below. Comparative Example 1 was manufactured in the same manner as in Example 1 except that pearlite was not charged, and Comparative Example 2 was manufactured in the same manner as in Example 3 except that pearlite was not charged.

[0010]

[Table 1]

[0011]

As described above, according to the present invention, since inorganic aggregates such as pearlite, sepiolite, and pebbles are laid on the filter material as a filter aid, the aqueous slurry is poured to perform dehydration molding. It is possible to prevent the above phenomenon and dehydrate the excess water of the aqueous slurry, and it is possible to shorten the time required for dehydration by press molding and improve the productivity.

Further, in the invention of claim 2 of the present invention, since the above-mentioned filter aid is a lightweight inorganic aggregate such as perlite, a lightweight inorganic plate can be obtained even if the inorganic aggregate is added. In addition, if it is porous such as pearlite, it is possible to obtain heat insulation.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an apparatus for performing the method of the present invention.

[Explanation of symbols]

 1 Lower mold 3 Filter material 4 Aqueous slurry 5 Inorganic aggregate

Claims (2)

[Claims] 1. A method for producing an inorganic plate, which comprises pouring an aqueous slurry containing cement as a main component into a mold and press-molding to remove excess water contained in the aqueous slurry through a filter medium. A method for producing an inorganic plate, which comprises laying an inorganic aggregate such as sepiolite or pebbles on a filter medium as a filter aid, and then pouring an aqueous slurry into the mixture for dehydration molding. 2. The method for producing an inorganic plate according to claim 1, wherein the filter aid is a lightweight inorganic aggregate such as perlite.