JPH0733298B2 - Method for producing inorganic extrudate - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing an inorganic extruded product.

[Conventional technology]

Conventionally, it is well known that asbestos is very useful as a reinforcing fiber for inorganic products such as cement.In the extrusion molding method, asbestos imparts lubricity to a kneaded product to improve the extrudability, and after extrusion molding. It also has the advantage of imparting the shape retention property of

However, since asbestos causes pollution, it is strongly requested to restrict or abolish its use, various fibers to replace it are sought, and pulp fibers are promising because they are excellent in heat resistance and alkali resistance. .

[Problems of conventional technology]

However, when pulp fibers are dry-mixed with a cement mixture, there is a problem that pulp fibers tend to be entangled with each other to form fiber balls, and so-called lumps cannot be obtained to provide a reinforcing effect commensurate with the addition. However, there was a problem in that the extrudability could not be sufficiently improved, the surface of the extruded product was rough, and the product surface was not smooth.

Further, since pulp fibers have water absorption, there is a problem that the freeze-thaw property of the product is adversely affected.

[Problems to be Solved by the Invention]

In view of the above problems, the present invention maintains the performance due to the addition of conventional extrusion aids, and the pulp fibers do not become so-called lumps during the kneading of the compound, without rough skin during extrusion molding,
It was made for the purpose of producing an extruded product having a good freeze-thaw property.

[Technology that has solved the problem]

That is, the method for producing an inorganic extruded product of the present invention is as follows: 3 parts by weight of pulp as reinforcing fibers, 0.5 to 1.0 parts by weight of methyl cellulose and 0.5 to 2.0 parts of cellulose powder, relative to 100 parts by weight of a semmeto compound consisting of cement, silica sand and clay. By mixing 1 part by weight, adding water, further kneading, extruding into a plate shape, and further shaping by pressing, primary curing of the shaped product shaped product, then applying and drying the paint, then autoclaving It is characterized by being cured.

[Action]

The cellulose powder used in the present invention may be either natural cellulose or regenerated cellulose, but fine particles having a particle size of 25 mesh of 1% or less and a particle size of 150 mesh of 30% or more are used.

By using this cellulose powder, as compared with the conventionally used pulp, densification of the structure is promoted, adverse effects such as roughening of the surface of the molded product at the time of extrusion are prevented, and more uniform mixing into the material is achieved. Fiber ball formation is prevented.

Further, since the particle size is reduced, the water absorption of the pulp itself can be reduced, which contributes to the improvement of the water absorption resistance and frost damage resistance of the product.

As a reinforcing fiber, only cellulose powder,
Since the fiber length is insufficient as a reinforcing fiber, ordinary pulp is also used together for the purpose of improving bending strength and the like.

In the present invention, the addition amount of the above-mentioned cellulose powder is regulated because if it is 0.5 parts by weight or less, freeze-thaw property and rough skin at the time of extrusion cannot be solved, and if it is 2.0 parts by weight or more, physical properties are deteriorated.

〔Example〕

 Next, an embodiment of the present invention will be described.

Based on 48 parts by weight of cement, 42 parts by weight of silica sand, 10 parts by weight of clay, and 3 parts by weight of conventionally used pulp (KLBP), cellulose powder (Example) or methylcellulose (Comparative Example) was used as a base compound. The ingredients other than water shown in the table are mixed with a dry mixer, and then the mixture shown in Table 1 is further mixed with a kneader blender while uniformly adding the water, and extruded using an extruder. The obtained shaped body is cut to obtain a test piece having a thickness of 15 mm, a length of 150 mm and a width of 200 mm, and the test piece is immediately cured at 30 ° C. to 60 ° C. at a relative temperature of 95% for 12 to 14 hours. Further, the autoclave was cured at 8.5 atm for 10 hours to cure and cure.

And about these, the test was done about the test item shown in Table 2.

In Table 1, the pulp is a hardwood bleached kraft pulp with a particle size of 35 mesh of 5% or less (manufactured by Kojinsha, trade name HP
-202) was used.

Also, as cellulose powder, water content is 10% or less, particle size is 25
A mesh having a residual amount of 1% or less, a material passing through 150 mesh of 30% or more, and a bulk specific gravity of 0.15 g / cc or more was used.

[Effect] As is clear from the results shown in Table 2, by adding cellulose powder, it is possible to produce a plate material having rough skin during extrusion of an inorganic plate material and excellent freeze-thaw performance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C04B 24/38 A 28/02 41/61

Claims (1)

[Claims] 1. A mixture of 100 parts by weight of a senmet compound consisting of semmet, silica sand and clay, 3 parts by weight of pulp as reinforcing fibers, 0.5 to 1.0 parts by weight of methyl cellulose and 0.5 to 2.0 parts by weight of cellulose powder, and watered. Further, the mixture is kneaded, extruded into a plate shape, and further shaped by a press to perform primary curing of the shaped product, and then the coating material is applied and dried, followed by autoclave curing. Method for manufacturing molded body.