JP2574182B2 - Extrusion molding method of inorganic plate - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extrusion method for an inorganic plate, and more particularly, to an improvement in an extrusion method for an inorganic plate containing no asbestos.

[Conventional technology]

Conventionally, building materials such as wallboards formed by fiber-reinforced cement have been used very widely.

An extrusion molding method is widely used as a method for producing these fiber-reinforced cement building materials.

It is widely known that asbestos is very effective as this fiber-reinforced cement building material reinforcing fiber.However, asbestos is a carcinogenic substance, and its use is strongly required to be restricted or abolished. At the present stage, pulp fibers and synthetic resin fibers are being widely used as effective.

[Problems of the prior art]

However, no matter which fiber is used, if the building material is formed by extrusion, the structure of the molded product becomes dense, so the obtained product becomes very heavy and hard, and saw cutting, which is required as a building material, The workability for nailing is very poor, and in the case of extruded wall boards, etc., when nailing at a position along the edge, the chipping of the edge occurs, making it impossible to fix with the nail itself. As a fatal drawback.

In particular, when the use of asbestos is completely abolished, the above-mentioned drawbacks become more remarkable because the reinforcing effect cannot be obtained. On the other hand, a lightweight aggregate is added to the cement compound for the purpose of reducing the weight of the inorganic plate and imparting workability. It is disclosed in JP-A-59-131405, but this method also results in poor surface smoothness due to the surface exposure of the lightweight aggregate and the reduction of extrusion resistance is also sufficient. In addition, there is a problem that a sufficiently satisfactory nailing property of the cured product cannot be obtained.

[Problems to be solved by the invention]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides an extruded inorganic plate having good extrudability, excellent surface smoothness, and excellent nailability even when extruded with a compound containing no asbestos. It was done to get the method.

[Technology that solved the problem]

That is, the extrusion method of the inorganic plate according to the present invention is performed by using a silica powder 10 to 70 wt.% Containing 10 to 60% by weight of cement and 5 to 15% of impurities such as clay mineral and talc, which are relatively uniform in particle size.
100% by weight of a blend composed of 1% to 10% by weight of a reinforcing fiber such as pulp, and an extrusion aid such as methylcellulose. It is characterized by adding 10 to 50% by volume of a material, dry-homogeneously mixing, adding an appropriate amount of water, kneading, extruding into a predetermined shape, and then curing in an autoclave.

[Action]

As the cement of the present invention, various portland cements, blast furnace cements, fly ash cements and the like can be used without any particular limitation.

The lightweight aggregate is used to improve the nailing performance at the same time as reducing the weight of the plate. As the lightweight aggregate, styrene foam or the like can be used in addition to the artificial lightweight aggregate. The reason why this lightweight aggregate is mixed in an amount of 10 to 50% by volume with respect to 100 parts by weight of the cement compound is to ensure nailability within 3 cm of the corner portion of the plate material. No improvement in hitting performance was achieved,
Conversely, if it exceeds 50% by volume, the bonding strength of the matrix becomes insufficient and the strength as a building material cannot be obtained.

The amount of the lightweight aggregate varies depending on the type of the lightweight aggregate. For example, in the case of perlite, 30 to 50% by volume is used.
Required, for styrene resin foam beads, 10-30
Volume% is required.

As the silica powder, one containing 5 to 15% of impurities other than SiO ₂ , feldspar, mica, calcium carbonate, clay mineral, talc and the like in the particles is used. That is, as shown in FIG. 2, the above-mentioned impurity 1 is not separated from the silica powder particles 2 but is incorporated in one particle of the silica powder 2 as shown in FIG. Is used. As the impurities, those containing clay minerals and talc are used because the extrusion resistance can be expected to be reduced due to the viscosity and the shape characteristics such as the flat shape of these impurities. If the content of minerals, talc, etc. is less than 5%, the surface smoothness and nailing properties will decrease due to the increase in extrusion resistance, and if it exceeds 15%, the strength will decrease.

The silica powder having a relatively uniform particle size refers to a particle having a particle size distribution in which the average particle size is concentrated at the center and is symmetrical with respect to the right and left, and particularly preferably a particle having a normal distribution.

Reinforcing fibers such as pulp include wood pulp, waste paper pulp, mineral fibers other than asbestos fibers, carbon fibers, glass fibers,
Synthetic fibers such as polypropylene fibers can be used. These fibers can be used alone or in combination.

〔Example〕

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

Portland cement as cement and silica powder having a particle diameter of 12 microns, containing clay minerals, talc, etc. in addition to SiO _{2 in} the proportions shown in the left column of Table 1 are added at the proportions shown in Table 1 respectively. And mixed uniformly.

In Table 1, the pulp was beaten, and as the lightweight aggregate, expanded polystyrene beads and perlite were used.
Methyl cellulose was used as an extrusion aid.

Water was further added to the mixture uniformly mixed at the ratios shown in Table 1, and the mixture was kneaded, extruded by an extruder, and extruded to a thickness of 10 mm.
Got something.

Next, this was subjected to autoclave curing under the conditions of a pressure of 8 kg / cm ² , a temperature of 178 ° C. and 12 hours.

The current (ampere) required for the extruder was measured as the surface state and extrusion pressure during extrusion molding, and the nailability of the product was measured.

 The results are as shown in the lower part of Table 1.

In addition, A and B in Table 1 show the particle size distribution of the powder to be added as shown in FIGS. 1A and 1B, and A shows the wide range particle size distribution shown in FIG. 1A. What you have.

B shows a normal distribution in which the particle sizes are concentrated as shown in FIG.

The evaluation of the surface state is as follows: ◎: the surface is very smooth,…: the surface is smooth, △: some scale-like scabs are generated.

The evaluation of nailing property is ◎: good, ○: good, ×: poor.

The nailing performance was determined by cracking when a nail was driven into the corner 3cm x 3cm.

〔effect〕

As described above, the present invention does not use asbestos, but uses a silica mineral powder containing particles of clay mineral, talc and the like as reinforcing fibers using pulp fibers and the like, so that the surface is smooth and extruded. It is a molding method that is easy to extrude due to a decrease in pressure, and since it contains a lightweight aggregate, it is possible to produce an inorganic plate having an effect such as excellent nailability.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) show the particle size distribution of the silica powder used in the examples. FIG. 2 and FIG. 3 are explanatory diagrams showing the state of particles of silica powder.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI Technical display location C04B 16:02 26:28) 111: 12

Claims (1)

(57) [Claims] 1. 10 to 60% by weight of cement, 10 to 70% by weight of silicalite powder having relatively uniform particle size, 5 to 15% of impurities such as clay mineral and talc in particles, and reinforcement of pulp and the like. Fiber 1
10 to 50% by volume of a lightweight aggregate such as an inorganic foam such as pearlite or foamed synthetic resin is added to 10% by weight and 100% by weight of a blend comprising an extrusion aid such as methylcellulose. A method for extruding an inorganic plate, comprising mixing uniformly, adding an appropriate amount of water, kneading the mixture, extruding the mixture into a predetermined shape, and then curing the mixture in an autoclave.