JPH07206544A - Method for extrusion molding of lightweight inorganic building material - Google Patents

Abstract

PURPOSE:To provide a method for extrusion molding of a lightweight inorganic building material capable of efficiently attaining lightening of a product. CONSTITUTION:In an extrusion blending material of a lightweight inorganic building material by blending 100wt.% of a cement blend comprising cement, a siliceous raw material, an aggregate and reinforcing fibers with 0.5-0.8wt.% of an extrusion auxiliary by an outer weight ratio, 10-20wt.% of a lightweight aggregate and 55-60wt.% of water, 100wt.% of the cement blend is mixed with 0.5-1.2wt.% by outer weight ratio of ground foamed styrol which is not reduced in volume during grinding by heat or obtained by removing ground foamed styrol reduced in volume and has <=0.02 bulk specific gravity and <=1.2mm particle size. The mixture is extrusion molded into a desired shape and the molded article is cured by an autoclave at >= the melting temperature of the ground foamed styrol.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion molding method for lightweight inorganic building materials.

[0002]

2. Description of the Related Art Conventionally, inorganic building materials made of fiber reinforced cement have been very widely used. As a method for producing these inorganic building materials, an extrusion molding method is known in which a cement mixture composed of cement, a silica raw material, an aggregate and a reinforcing fiber is kneaded with an appropriate amount of water, and this is extruded from a molding die. By the way, in the case of the extrusion molding method of this inorganic building material, since the extrusion pressure above a certain level is applied to the molding material, the product tends to have high density and high hardness, which is convenient in terms of improving the product strength, but the product is heavy and nailed. There was a problem that the workability of punching and saw cutting was poor. Therefore, in order to solve such a problem, an inorganic foamed lightweight aggregate such as pearlite or an organic foamed lightweight aggregate such as expanded styrene beads is added to the extrusion compounding material to make the product structure porous to reduce the specific gravity and processability. Improvements are being made.

[0003]

However, in the case of the former method of adding the inorganic foam lightweight aggregate among the above-mentioned weight-reducing techniques, the inorganic foam lightweight aggregate is often crushed in the extruder, and therefore, the addition is not recommended. There is a problem that it is difficult to achieve a suitable weight reduction, and in the latter method of adding organic foam lightweight aggregate, after being compressed and passing through the molding die, the organic foam lightweight aggregate contained in the material is springback. Due to the phenomenon, the product expands and restores, which causes fine irregularities on the product surface, resulting in a problem that the product surface is not smooth. However, such problems can be solved by crushing the organic foamed lightweight aggregate until it becomes a very fine powder, but the organic foamed by the heat due to the impact or friction during the pulverization applied to the organic foamed lightweight aggregate. There is a problem in that the lightweight aggregate causes a phenomenon of reducing the volume, and as a result, the bulk specific gravity is increased, and even if the phenomenon such as the springback described above can be eliminated, sufficient weight reduction cannot be achieved.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide an extrusion molding method for an inorganic building material, which is an extrusion molding method for a lightweight inorganic building material, which can efficiently reduce the weight of a product. It was made as.

[0005]

That is, the method for extrusion molding a lightweight inorganic building material of the present invention is to provide a cement, a siliceous raw material,
0.5 to 0.8% by weight of extrusion aid, 10 to 20% by weight of lightweight aggregate and 55 to 60% by weight of water are added to 100% by weight of cement mixture consisting of aggregate and reinforcing fiber in an external weight ratio. Extruded and compounded materials for lightweight inorganic building materials, extruded styrofoam that has not been reduced in volume or reduced in volume due to heat during pulverization, and has a bulk specific gravity of 0.02 or less and a particle size of 1.2 mm or less. 0.5 to 1.2% by weight of the crushed styrene foam of
It is characterized in that it is added, the kneaded product is extruded into a predetermined shape, and then the autoclave is cured at a temperature equal to or higher than the melting temperature of the styrofoam crushed product.

[0006]

The extruding compounding material of the lightweight inorganic building material used in the present invention is an extruding aid of 0.5 to 100% by weight with respect to 100% by weight of the cement compounding mixture consisting of cement, siliceous raw material, aggregate and reinforcing fiber. It is a composition obtained by adding 0.8% by weight, 10 to 20% by weight of lightweight aggregate, and 55 to 60% by weight of water, which is the same as the conventional one, and there is no particular point on this point.

In the present invention, a styrofoam crushed product with respect to the above composition, which has not been reduced in volume by heat during pulverization or has been reduced in volume, has a bulk specific gravity of
A styrene foam crushed product with a particle size of 0.02 or less and a particle size of 1.2 mm or less is 0.5% by weight based on 100% by weight of the above cement mixture.
Add ~ 1.2% by weight. The reason for adding this styrofoam resin is to achieve weight reduction of the extrusion molded product. This styrofoam resin is obtained by removing one that has not been reduced in volume by heat during pulverization or one whose volume has been reduced. It has a bulk specific gravity of 0.02 or less and a particle size of 1.2 mm or less. The reason for this is that the volume reduced by the heat during pulverization has a bulk specific gravity of more than 0.02, and therefore even if added, the weight reduction cannot be sufficiently achieved. The particle size is 1.2 mm or less in order to prevent the springback phenomenon after extrusion molding. If it is larger than 1.2 mm, the surface smoothness due to the springback phenomenon cannot be obtained.

[0008] The addition amount of this styrofoam crushed resin is 0.5-1.
If 2% by weight is added, less than 0.5% by weight will not achieve sufficient weight reduction, and if it is more than 1.2% by weight, it will be convenient in terms of weight reduction, but the relative volume of addition of ground polystyrene foam resin will be large. This is because the bond strength of the cement matrix is weakened, and at the same time, the product is distorted due to the springback phenomenon of the entire extrusion molded body.

In the above, when crushing Styrofoam, the means for not reducing the volume by the heat during crushing depends on the conditions such as the tooth gap of the crusher, the number of revolutions, and the particle size of the coarse crushing, but common effective means. For this, crushing teeth with a cooling jacket inside are used.

[0010]

Embodiments of the present invention will be described below.

First, a styrofoam resin is crushed by using a crusher equipped with a cooling jacket inside the teeth to prevent a temperature rise during crushing, and a bulk specific gravity of 0.02 or less and a particle size of 1.2 mm.
The following styrofoam pulverized product was obtained. (Example 1) Cement 42% by weight, silica sand 40% by weight, aggregate 13
Wt%, pulp fiber 5 wt% total 100 wt%,
0.7% by weight of methyl cellulose as an extrusion aid,
As the inorganic lightweight aggregate, the basic composition is a composition obtained by adding 15% by weight of perlite to the outer part and 55 to 60% by weight of water to the outer part. Below, a styrene foam pulverized product with a particle size of 1.2 mm or less is 0.
5% by weight was added, and the kneaded product was extrusion-molded into a cross-sectional shape having a thickness of 2 cm and a width of 20 cm to obtain a plate-shaped test piece having a length of 50 cm.

(Example 2) A plate-shaped test piece was obtained in the same manner as in Example 1 except that the amount of the finely ground polystyrene foam resin added in Example 1 was 1.0% by weight relative to 100% by weight of the cement mixture. It was

(Example 2) A plate-like test piece was obtained in the same manner as in Example 1 except that the amount of the finely ground polystyrene foam resin added in Example 1 was 1.2% by weight relative to 100% by weight of the cement mixture. It was

(Comparative Example 1) A plate having the same shape as that of Example 2 except that a styrofoam crushed product having a volume specific gravity of 0.05 or less and a particle size of 1.2 mm or less was used to reduce the volume by heat during crushing. A test piece was obtained.

(Comparative Example 2) Example 2 was repeated except that a styrene foam pulverized product having a volume specific gravity of 0.05 or less and a particle size of 1.2 mm or less was used by reducing the volume by heat during pulverization and the addition amount thereof was 2.0% by weight. A plate-shaped test piece having the same shape as in Example 2 was obtained in the same manner as in.

(Comparative Example 3) The same procedure as in Example 2 was carried out except that 1.0% by weight of a styrene foam pulverized product having an average particle size of 2 mm and a bulk specific gravity of 0.02 was added, although the volume was not reduced by heat during pulverization. A plate-shaped test piece having the same shape as 2 was obtained.

The above Examples 1 to 3 and Comparative Examples 1 to 3 were naturally cured at room temperature for 6 hours, and then autoclaved at 180 ° C. for 12 hours to be cured. The obtained test piece was subjected to bending strength, specific gravity, nailing test, and surface state observation test, and the results shown in Table 1 were obtained.

In Table 1, "bending strength" means JIS.
It is based on the No. 4 bending test, and the unit is kg / cm ² . The "nailability" is the number of nails that are driven into the corners of the test plate 20 mm x 20 mm and which does not cause cracks and chips, relative to the number of test objects. "Surface condition" refers to the presence or absence of unevenness due to springback. ○ indicates that the surface is smooth and good, △ indicates slight unevenness but a smooth surface is maintained, and × indicates unevenness. Shows what is seen in.

As is apparent from Table 1, all the test pieces obtained by the present invention have a specific gravity within the range of 1.015 to 1.011 to achieve weight reduction and have sufficient bending strength. did. It should be noted that Comparative Example 1 is excellent in strength but is not capable of nailing at all, Comparative Example 2 is unacceptable in terms of strength, specific gravity and surface condition, and Comparative Example 3 is excellent in terms of specific gravity but not in surface condition at all. Met.

[0020]

[Table 1]

[0021]

As described above, according to the present invention, in the conventional extrusion molding compounding of a lightweight inorganic building material, as an additive material for reducing the weight, one which has not been reduced in volume by heat during pulverization or one whose volume has been reduced Since the styrofoam pulverized product from which is removed is used, it is possible to achieve a sufficient weight reduction with a small amount of addition and to sufficiently eliminate surface defects due to springback.

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Claims (1)

[Claims] 1. An extrusion aid of 0.5 to 0.8% by weight and a lightweight aggregate of 10 to 20% by weight based on 100% by weight of a cement mixture consisting of cement, a siliceous raw material, an aggregate and a reinforcing fiber. For extruded compounding materials of lightweight inorganic building materials made by adding 55 to 60% by weight of water, it is a styrene foam pulverized product,
Those that have not been or have been reduced in volume by the heat of crushing, and have a bulk specific gravity of 0.02 or less and a particle size of 1.2 mm or less are crushed styrofoam, and the outer weight is based on 100% by weight of the above cement mixture. A method for extrusion-molding a lightweight inorganic building material, comprising adding 0.5 to 1.2% by weight of the mixture, extruding the kneaded product into a predetermined shape, and then curing the autoclave at a temperature equal to or higher than the melting temperature of the styrofoam crushed product.