JPH06144911A - Extrusion molding method for fiber reinforced inorganic product - Google Patents

Abstract

PURPOSE:To improve bursting resistance by kneading a cement, a silica fume/ silica sand mixture, a synthetic fiber, a treated pulp fiber, a microbaloon and a water reducing agent and after molding, steam curing and autoclave curing. CONSTITUTION:A silica constituent composed of a mixture having (15-25)/(85-75)wt.% silica fume having >=8000cm<2>/g particle size to silica sand are mixed with the cement by a prescribed weight ratio. Into the mixed material, 0.05wt.% more reinforcing fiber than asbestos such as PR fiber, 5-7wt.% pulp fiber on which a silica particulate is previously fixed, 6-10 volume % aggregate such as the micorbaloon made of polyvinylidene chloride and 0.5-1.5wt.% cement based water reducing agent such as naphthalenesulfonic acid-formaldehyde condensation product to (cement + silica) are added and kneaded. Next, the high strength and bursting resistant fiber reinforced inorganic product is obtained by extruding the kneaded material and after steam curing the molded material, autoclave curing in >=4kg/cm<2> condition and air drying.

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 fiber-reinforced inorganic products, and more particularly to an improvement in extrusion molding method for fiber-reinforced inorganic products containing asbestos.

[0002]

2. Description of the Related Art Conventionally, an extrusion molding method is well known as a molding method for inorganic products such as fiber reinforced cement products. Asbestos has been traditionally used as a reinforcing fiber for these inorganic products, but asbestos is a cause of pollution and is required to be completely abolished due to resource depletion. Various fibers have been proposed and tried.

[0003]

[Problems of the prior art] However, the reinforcing effect of asbestos fibers is far superior to the fibers that have been considered so far, and reinforcing fibers other than asbestos that can exhibit the same strength as the use of asbestos have not been found. Not issued. Therefore, in order to obtain the same strength as the use of asbestos, in extrusion molding, it is necessary to increase the bonding strength of the cement matrix, and for this reason, high pressure extrusion molding with an extrusion pressure of 40 kg / cm ² or more is required. There is a problem that a large horsepower is required for the above and the manufacturing cost is high. In addition, in order to increase the dimensional stability of these extruded products, the products are often autoclaved, but due to the synergistic effect of the high extrusion pressure and autoclave curing, the product structure becomes too compact and the strength is high, but explosion occurs during a fire. There was a drawback that the product was easy to do.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention can obtain the same strength as that of using asbestos while being a non-asbestos blend, and has excellent explosion resistance and low manufacturing cost. The purpose of the present invention is to provide an extrusion molding method for fiber-reinforced inorganic products.

[0005]

That is, the method of extrusion molding a fiber-reinforced inorganic product according to the present invention comprises cement, silica content,
Silica fume as the silica component and silica sand with a particle size of 8,000 cm ² / g or more in the extrusion molding of fiber-reinforced inorganic products containing reinforcing fibers other than asbestos, lightweight aggregates and extrusion aids, silica fume: silica sand = 15-25: 85-75 mixture as a reinforcing fiber other than asbestos, 0.05% or more of the synthetic fiber and 5-7% of the same amount of silica fine powder pre-fixed on the surface of the above-mentioned mixture for extrusion molding. Pulp fiber and 6 to 10% by volume of microballoon as the aggregate and 0.5% of cement and silica content.
A cement water reducing agent of up to 1.5 wt% is added and kneaded, and the kneaded product is extrusion-molded, steam-cured, and then autoclaved at 4 kg / cm ² or more.

[0006]

In the present invention, the amounts of cement, silica, reinforcing fibers other than asbestos, lightweight aggregates and other extrusion aids used as an extrusion molding compound are the same as in the prior art. However, among these materials used, the content of silica and the content of reinforcing fibers are different.

That is, in the method of the present invention, the silica content is silica fume and silica sand having a particle size of 8,000 cm ² / g or more, and a mixture of silica fume: silica sand = 15-25: 85-75 is used. Silica sand with a particle size of 8,000 cm ² / g or more is the same as before, but silica fume: silica sand = 15 to 25: 8
Add and mix silica fume so as to be 5 to 75.

The reason why silica fume is added in such a ratio is to optimize the CHS autoclave hydration reaction of the cement matrix and to develop a suitable strength. Silica fume: silica sand = 25: 75 When the fume is increased, the structure of the cement matrix becomes too dense and the strength is improved, but the explosion resistance cannot be obtained. On the other hand, when silica sand is increased from the ratio of silica fume: silica sand = 15: 85, the hydration reaction is insufficient and the bond strength of the cement matrix becomes insufficient, making it difficult to obtain a product having sufficient strength.

Next, as a reinforcing fiber other than asbestos, a synthetic fiber which does not melt and decompose even in an autoclave curing condition of 4 kg / cm ² or more with respect to the above extrusion compounding is used as an uncured product. This is because the shape retention property is imparted to, and the shape retention property that cannot be obtained with pulp is supplemented. In addition, as the heat resistance condition of this synthetic fiber, the autoclave curing condition is 4
The reason why the material that does not melt and decompose even under the condition of kg / cm ² or more is used is to contribute to the product strength even after curing and curing. Is. As such synthetic fibers, polypropylene fibers, polynosic rayon fibers, etc. are officially used. The amount of addition is 0.05% or more with respect to the composition for extrusion molding, because if it is less than this, the effects such as shape retention cannot be obtained.

The pulp fibers to which silica fine powder is fixed beforehand are used as the pulp fibers in order to improve the chemical bonding property between the pulp fibers and the cement matrix. Water that has been added with a fixing agent, mixed and then dried is used.
This is because the addition amount of this pulp fiber is the same as that of the conventional formulation, and if it is less than 5% with respect to the formulation for extrusion molding, the reinforcing effect cannot be obtained, and if it is more than 7%, the fire resistance of the product is impaired.

The reason why the microballoons are used as an aggregate in the composition for extrusion molding is to reduce the weight of the product and to form the voids in the matrix to impart explosion resistance, and the microballoons made of polyvinylidene chloride are preferable. Used for. The amount of the microballoons added to the mixture for extrusion molding is 6 to 10% by volume, when the amount is less than 6% by weight, sufficient weight reduction cannot be achieved. This is because the addition amount of is reduced and a sufficient bond strength of the matrix cannot be obtained.

The use of the cement-based water reducing agent improves the fluidity of the cement slurry in combination with the extrusion aid to reduce the extrusion pressure and enhances the dispersibility of the powder such as cement and silica sand. The dispersion of the subsequently agglomerated particles is improved to eliminate coarse voids in the matrix and enhance the strength. As this cement-based water reducing agent, naphthalene sulfonic acid formalin condensate is preferably used. The amount of addition of 0.5 to 1.5% by weight relative to the cement and silica content is not effective if it is less than 0.5% by weight, and even if it is more than 1.5% by weight, no further effect can be expected and it is wasted. Because.

40 kg / cm by using the above silica fume and silica sand with a particle size of 8,000 cm ² / g or more, synthetic fiber, pulp fiber in which fine silica powder is fixed on the surface beforehand, use of microballoon and use of cement-based water reducing agent. A product with sufficient strength can be obtained even by molding with an extrusion pressure of ² or less, and explosion resistance is realized due to the appropriate bond strength of the matrix.

[0014]

Embodiments of the present invention will be described below. Cement, silica fume and silica sand as silica component, pulp fiber and polynosic rayon as reinforcing fiber other than asbestos, hollow particles of polyvinylidene chloride resin as microballoon (Matsumoto Yushi-Seiyaku Co., Ltd .: trade name "Microsphere"), cement-based A naphthalene sulfonic acid formalin condensate (Kao Corporation: trade name "Mighty 150") was prepared as a water reducing agent.

First, 40% by weight of defibrated pulp has a particle size of 10,0.
Add 60% by weight of silica fine powder of 00 cm ² / g, add 30% by weight of water with 5% concentration of fixing agent to the outside, mix evenly with a mixer, dry and sieve to fix silica fine powder on the surface. The pulp fiber which was made to obtain was obtained. Also, silica fume and grain size of 8,000
Silica fume: silica sand = 15:85 (silica A), 25:75 (silica B), silica fume and particle size 9, 0 cm ² / g
Silica content was adjusted by setting 000 cm ² / g of silica sand to silica fume: silica sand = 15: 85 (silica C) and 25:75 (silica D).

The above materials were added in the composition shown in Table 1, water was added so that the extrusion pressure was in the range of 18 to 25 kg / cm ² , the cement slurry was adjusted, and this slurry was extrusion-molded to obtain the thickness. A plate-like body having a width of 12 mm, a width of 200 mm and a length of 1,000 mm was formed. At this time, the amount of sag of a 150 mm span of the molded product immediately after discharge was measured. The extruded product was steam-cured at 30 to 60 ° C. for 12 hours, then autoclaved at 6 kg / cm ² × 8 hours, and then air-dried for 7 days to obtain a test plate. The test plate thus obtained was tested for bending strength and explosive seconds. The results shown in Table 2 were obtained.

[0017]

[Table 1] In Table 1, * 1 Matsumoto Microsphere * 3 Only fly ash is used * 2 Only silica sand with a particle size of 3,500 cm ² / g is used * 4 No silica fixing treatment

[0018]

[Table 2] In Table 2, * 1 The test plate was exposed to a flame of 925 ° C for 10 minutes by the test method based on the Slate Association method, and the number of seconds until explosion occurred during that time was measured. * 2 This is a measurement of the amount of sag at the center, with the uncured plate material immediately after extrusion supported by a span of 150 mm.

As is clear from Tables 1 and 2, it was found that the examples of the present invention can obtain a product strength despite the low extrusion pressure and can form a product which is less likely to explode.

[0020]

As described above, by selecting and treating the reinforcing fiber, and combining silica sand and silica fume, which is a silica component, micro balloons, and a water reducing agent, it is possible to obtain high strength and durability that cannot be realized by the conventional extrusion molding method. It has become possible to extrude fiber-reinforced inorganic products having explosive properties.

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display area C04B 16:06 Z 2102-4G 16:02 2102-4G 14:04 Z 2102-4G 18:14 Z 2102-4G 14:16 2102-4G 24:22) A 2102-4G

Claims (1)

[Claims] 1. A compound for extrusion molding of a fiber-reinforced inorganic product containing cement, silica content, reinforcing fiber other than asbestos, lightweight aggregate and extrusion aid, with silica fume as the silica content and a particle size of 8,000 cm ² / g or more. Silica fume: silica fume: silica sand = 15 to 25:85 to 75 as a reinforcing fiber other than asbestos in a content of 0.05% with respect to the composition for extrusion molding.
The above synthetic fibers and 5 to 7% of the pulp fibers having the fine silica powder fixed on the surface in advance are used as the aggregate and 6 to 10% by volume of the microballoon with respect to the above-mentioned composition, and the cement. A fiber characterized by adding 0.5 to 1.5% by weight of a cement-based water reducing agent to silica and kneading, extruding the kneaded product, steam curing, and autoclave curing under conditions of 4 kg / cm ² or more. Extrusion molding method for reinforced inorganic products.