JPH0577221A - Roof tile manufacturing method - Google Patents

Abstract

(57) [Summary] [Purpose] A roof tile made of a fiber reinforced hydraulic inorganic composition can be formed without impairing fluidity, and a method of manufacturing a roof tile having high strength and durability is provided. To do. A method for manufacturing a roof tile, which comprises: extruding a slurry containing a hydraulic inorganic substance, water, an inorganic filler, and reinforcing fibers into a corrugated plate by extrusion molding, cutting, and then curing and curing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a roof tile made of a fiber-reinforced hydraulic inorganic composition.

[0002]

2. Description of the Related Art Conventionally, as roof tiles, clay tiles such as Yuzu leaf tiles and Ibushi tiles have been well known for a long time and are most often used. However, recently, the quality of clay has decreased, and it has become difficult to mass-produce good-quality clay. Therefore, roof tiles using so-called hydraulically cured inorganic materials such as thick-type slats and cement roof tiles are produced. However, since these use a large amount of water with respect to the stoichiometry in order to improve moldability, it takes time for dehydration and demolding steps, and it is difficult to increase productivity. Further, since these have a small bending strength, the weight of the roof tile must be increased in order to obtain a sufficient withstand load, which is disadvantageous in terms of operation and cost.

By the way, since the tensile strength of a molded body made of a hydraulic inorganic substance is lower than that of the compressive strength, a method of incorporating a reinforcing material is often used. For example, in a cement molded product, asbestos is mixed as a reinforcing material in order to improve the moldability during molding and to increase the mechanical strength after curing. However, in recent years, the problem of carcinogenicity caused by using asbestos has been pointed out. Therefore, various synthetic fibers have been used as a reinforcing material to replace asbestos.

As a method for producing a roof tile from a fiber reinforced cement mixture using synthetic fibers as a reinforcing material, it is shaped by pressing dehydration molding as described in, for example, JP-A-63-222806. The method for producing roof tiles of various shapes, and as described in Japanese Patent Publication No. 1-23427, a plurality of layers are laminated so that paper is scooped from water mixed with fiber reinforced cement material, and then There is a so-called paper-making method in which pressing is performed with a wavy roll or the like.

Further, Japanese Patent Publication No. 57-19009 discloses that
A method in which 0.5 to 10 parts by weight of short fibers and 17 to 35 parts by weight of water are mixed with 100 parts by weight of cement, kneaded, extruded into a plate shape by an extrusion molding machine, and subsequently pressed into a roof tile shape by a pressing machine. Is disclosed.

Therefore, in order to obtain a high-strength hydraulic inorganic molded article, as described in Japanese Patent Application Laid-Open No. 2-160650, silica sand having a brain value of 3,000 cc / g or more (mean particle size) 5 to 10 microns or less, but there is no exact correspondence because it differs in shape.) Composition in which water is added in an amount as close as possible to the stoichiometry of 20 to 35 parts by weight to 100 parts by weight of cement mixed. There is disclosed a method of filling the above voids with fine particles, such as molding a high-strength lightweight roof tile by extrusion molding using a material.

[0007]

However, in the press dehydration molding method described in JP-A-63-222806 and the paper-making method described in JP-A-1-23427, the fineness of the structure is It has a drawback that it is difficult to be made into a solid material and has poor durability such as frost damage resistance.
According to the method described in JP-A-19009, the amount of mixed short fibers is set to 0.5 to 10 parts by weight, but the most remarkable mixing effect is 2 to 5 parts by weight, and 5 parts by weight or more. When mixed, there is a problem that dispersion becomes poor and the mechanical properties of the molded product deteriorate.

Further, in the production method described in JP-A-2-160650, since the water-cement ratio is small and the specific surface area of the fine particles is very large, water is adsorbed by the fine particles and the fluidity of the composition is increased. However, there is a problem in that a molded product having a simple shape such as a flat plate as described in the above publication can be shaped, and it cannot be applied to a molded product having a complicated shape.

When the roof tile is loaded from above, bending stress is generated, and tensile stress is generated below the roof tile. The molded product using the hydraulic inorganic cured product has excellent compressive strength, but has low tensile strength. Therefore, in order to withstand the above-mentioned loads, a compact having a simple shape such as a flat plate requires a considerable thickness. Further, in order to form by press molding using the kneaded product described in the same publication, it is necessary to perform the molding under an extremely high pressure, and since the kneaded product has low fluidity, a large-sized molded product can be obtained. Was extremely difficult.

The object of the present invention is to solve the above problems, and even a roof tile made of a fiber reinforced hydraulic inorganic composition can be molded without impairing the fluidity, has high strength and is excellent in durability. It is intended to provide a method for producing a hard inorganic molded body.

[0011]

The hydraulic inorganic substance used in the present invention is not particularly limited as long as it is an inorganic substance which shows a hardening property when kneaded with water. For example, ordinary Portland cement, special Portland cement, alumina cement, Examples include plain cements such as Roman cement, acid-resistant cements, fire-resistant cements, special cements such as water glass cements, and air-hardening cements such as gypsum, lime, and magnesia cements. Particularly, in terms of strength and water resistance, Portland cement and alumina cement are preferably used.

If the amount of water used in the production method of the present invention is less than 15 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance, the hydraulic inorganic substance is not sufficiently cured, and
The dispersibility of the reinforcing fibers and the inorganic filler decreases, and when the amount exceeds 60 parts by weight, the mechanical strength of the obtained molded product decreases, so that the amount is preferably 15 to 60 parts by weight.

The inorganic filler used in the production method of the present invention does not dissolve in water, does not inhibit the curing reaction of the hydraulic inorganic substance, and remarkably functions of all the constituent materials used in the production method of the present invention. There is no particular limitation as long as it does not inhibit, for example, aggregate for cement mortar such as silica sand and river sand, fly ash, silica flower, silica fu
Examples include mixed cement admixtures such as aluminum, bentonite, and blast furnace slag, and natural minerals such as sepiolite, wollastonite, calcium carbonate, and mica. These may be used alone or in combination of two or more kinds.

The above-mentioned inorganic filler has an average particle size of 0.03.
If it is less than μm, the dispersibility of the particles of the inorganic filler between the reinforcing fibers is not further improved, and only the difficulty in production is raised. Since it becomes difficult for the particles to disperse and the reinforcing fibers tend to aggregate, 0.03 to 500 μm is preferable. When the amount of the inorganic filler is less than 2 parts by weight with respect to 100 parts by weight of the hydraulic inorganic substance, particles of the inorganic filler are difficult to disperse between the reinforcing fibers, so that the reinforcing fibers easily aggregate, and when the amount exceeds 200 parts by weight. It is preferably 2 to 200 parts by weight because the strength of the obtained molded article is reduced.

As the reinforcing fiber used in the present invention, any reinforcing fiber can be used according to the performance to be imparted to the molded product, and examples thereof include vinylon, polyamide, polyester,
Polypropylene, carbon, synthetic fibers such as aramid,
Glass fiber, pulp, etc. can be used. Particularly when synthetic fibers are used, the flexibility is remarkably improved. If the thickness of the above-mentioned reinforcing fiber is too thin, it reaggregates during mixing, fiber fibers are likely to be formed due to entanglement, and the strength of the obtained molded product is not further improved, either too thick or too short. And a reinforcing effect such as improvement in tensile strength are small, and if it is too long, the dispersibility and orientation of the fibers are deteriorated, so that the thickness is 0.
5 to 40 denier and a length of 1 to 15 mm are preferable. The amount of the reinforcing fibers was 0.
If it is less than 1 part by weight, the reinforcing effect is small, and if it exceeds 20 parts by weight, the dispersibility of the fiber is lowered, so 0.1 to 20 parts by weight is preferable.

In the present invention, a water-soluble polymer substance may be added if necessary. The water-soluble polymer substance dissolves in water to impart viscosity, enhances dispersibility of the inorganic filler and reinforcing fiber, enhances fluidity of the mixture to improve shapeability, and also cement hardening It is not particularly limited as long as it is a polymer substance that can absorb excess water in the body and serve as a binder to fill voids between cement particles, and examples thereof include methyl cellulose, hydroxymethyl cellulose, hydroxyethyl cellulose and carboxymethyl. Examples thereof include cellulose ethers such as cellulose and hydroxypropylmethyl cellulose, polyvinyl alcohol, and polyacrylic acid.

In the method of manufacturing a roof tile according to the present invention, first, a slurry obtained by kneading the above-mentioned hydraulic inorganic substance, water, an inorganic filler and a reinforcing fiber is extruded into a corrugated plate-shaped mold and applied. It is characterized in that it is shaped, cut and then cured and cured.
When the thickness of the extrusion passage of the mold is too thin, the strength of the obtained molded product is low, and when it is too thick, the weight of the molded product obtained is increased, so 3 to 10 mm is preferable. If the curvature of the extrusion passage is too small in the mold, the moldability is lowered, and if it is too large, the strength of the obtained molded product is lowered, so that the curvature is 20 to 60.
mm is preferred. If the length of the die in the extrusion direction is too short, the molding strain applied to the molded product increases, and if it is too long, the back pressure required for extrusion molding increases, so that the length is preferably 50 to 300 mm. As the extruder used in the present invention, any conventionally known extruder can be used.
It can be molded with a back pressure of -80 kg / cm ² .

The continuous molded body obtained by the above molding method is cut into a required size. As the cutting method, any conventionally known method can be used, for example, a diamond cutter or a water jet can be used. Mechanical properties can be improved by performing curing by a conventionally known method such as further heating and humidifying the molded body obtained by the above molding method.

[0019]

EXAMPLES The details of the present invention will be described in more detail with reference to Examples. Example A predetermined amount of ordinary Portland cement shown in Table 1, vinylon fiber (thickness 2 denier, length 6 mm), JIS No. 9 silica sand (particle size 100 μm), hydroxypropylmethylcellulose (2% aqueous solution at 20 ° C.) Has a viscosity of 30,000
(0 cps) and water were put into a mixer having a capacity of 10 liters and mixed. After that, the mixture which is kneaded and integrated by a clay kneader has an extrusion passage having a thickness of 5 mm, a width of 600 mm and a curvature of 3
Back pressure of 23 kg / cm ² with a vent type extruder with a barrel diameter of 200 mm in a 100 mm long mold with a corrugated shape of 0 mm.
And extruded with a water jet to cut it to a length of 400 mm, and the temperature was 60 ° C and the relative humidity was 95%.
After curing for 6 hours, corrugated roof tiles were obtained.

Comparative Example 1 A kneaded product obtained in the same manner as in Example had an extrusion passage having a thickness of 5
Extruded in the same manner as in the example into a metal mold having a width of 600 mm, a width of 600 mm and a length of 100 mm, and a flat roof tile was obtained from the obtained molded product in the same manner as in the example.

Comparative Example 2 A predetermined amount of Portland cement, vinylon fiber, silica sand, hydroxypropylmethyl cellulose and water shown in Table 1 were obtained in the same manner as in Example 1 to obtain a kneaded product, which was then subjected to the dewatering press method. The roof tile of the same shape was obtained.

Comparative Example 3 A kneaded product was obtained in the same manner as in Example 1 except that the prescribed amounts of Portland cement, vinylon fiber, silica sand, hydroxypropylmethylcellulose and water shown in Table 1 were used. Got the roof tile of.

The molded articles of Examples and Comparative Examples 1 to 3 obtained above were subjected to the following tests. The above results are also shown in Table 1.

[0024]

[Table 1]

Evaluation of Physical Properties Bending Fracture Load A load was applied to the center of the obtained molded body to measure the fracture load. Freezing and thawing performance Evaluated according to the ASTM C-666A method, JIS A
The number of cycles in which the bending strength measured according to the method of 1408 reached 90% was shown.

[0026]

As described above, the method for producing a roof tile according to the present invention is carried out by extruding a slurry containing a hydraulic inorganic substance, water, an inorganic filler, and a reinforcing fiber into a corrugated plate by extrusion, followed by cutting and curing. Since it is hardened, it is possible to obtain a material having excellent load resistance as compared with a flat roof tile. In addition, because it is formed by extrusion molding, the structure can be made denser than conventional pressure dehydration molding and papermaking methods, and roof tiles that are not only excellent in load bearing but also durable in frost damage resistance etc. Obtainable.

Claims (1)

[Claims] 1. A method for producing a roof tile, comprising a step of extruding a slurry containing a hydraulic inorganic substance, water, an inorganic filler, and reinforcing fibers into a corrugated plate by extrusion molding, followed by cutting and curing and curing.