JPH03120007A - Manufacture of inorganic plate - Google Patents

Abstract

PURPOSE:To eliminate the difference between the longitudinal and transverse strengths of a plate molded continuously to obtain an inorganic plate of average strength by roll-pressurizing an unhardened inorganic plate in two directions differing 90 deg. crosswise from each other before cure-hardening the unhardened inorganic plate. CONSTITUTION:Before an unhardened inorganic plate molded from a cement compound with reinforcing fibers added thereto is cure-hardened, the unhardened inorganic plate is roll-pressurized in two directions differing 90 deg. crosswise from each other. When an unhardened inorganic plate is roll-pressurized in one direction in general, the reinforcing fibers are arranged in that direction and a flexural strength in the fiber arranging direction is improved in combination with hardening of compaction of cement matrix. Therefore, when this roll pressurization is performed in the longitudinal and transverse two directions differing 90 deg. from each other, the fibers find to be arranged in the two directions. Thus, the difference between longitudinal and transverse strengths decreases so much and it possible to obtain a plate of uniform strength.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a method for manufacturing an inorganic plate material.

[Conventional technology]

BACKGROUND ART Conventionally, it has been widely practiced to mold architectural board materials such as exterior wall boards and flat roofing materials from fiber-reinforced cement compounds.

In addition, as a continuous manufacturing method for the above-mentioned inorganic board materials, there is a paper-making method in which a compound is extracted from cement milk and this paper-formed film is laminated to a predetermined thickness, or a dry powder raw material is supplied in layers onto a forming heald and water is added. A dry method for leveling to a constant thickness is well known.

In any of the above-mentioned manufacturing methods, in order to impart bending strength and flexibility to the molded plate material, the process includes a pressurizing step in which pressurization with a roll is performed once or twice.

[Problems with conventional technology]

By the way, since the above-mentioned pressure is applied during the continuous forming process, roll pressure is applied only in one direction along the feeding direction of the molded product. Only an improvement in bending strength can be obtained, and the strength in the width direction tends to be insufficient, resulting in the problem that warping of the plate cannot be effectively prevented.

In addition, in the case of flat roofing materials with a shape with a vertical and horizontal dimension ratio close to 1, care must be taken when transporting and handling them due to the above-mentioned difference in strength between the vertical and horizontal directions. There was a problem in that it was more likely to occur.

[Problem to be solved by the invention]

In view of the above-mentioned problems, the present invention has been made with the object of providing a method for manufacturing an inorganic plate material having a strength that is the average of the longitudinal and lateral strength differences of continuously molded plate materials.

[Technology that led to solving the problem]

That is, the method for producing a quality-free plate material of the present invention (prior to curing and curing an uncured inorganic board material formed from a cement mixture containing m strong fibers), It is characterized by applying roll pressure in the direction.

[Effect]

-C, when roll pressure is applied to uncured inorganic board material in one direction, reinforcing fibers are arranged in that direction, and the bending strength in the direction of fiber arrangement is improved by synergizing with the compaction effect of the cement matrix. .

Therefore, if this roll pressure is applied in two different vertical and horizontal directions in the 90'' direction, the fibers will tend to be arranged in the above two directions, and the difference in vertical and horizontal strength will be reduced accordingly, resulting in a plate material with uniform strength.

〔Example〕

Next, the present invention will be explained in detail.

Example 1 A cement mixture consisting of 30% by weight of cement, 66% by weight of aggregates such as silica, and 4% by weight of reinforcing pulp fibers was mixed with a large amount of water to prepare cement milk, and a thickness of 4.51 mm was prepared by a papermaking method. The plate material was molded.

After pressing the obtained raw original plate flat with a press, it is 45 cm long.
+o, cut with a cutter to a width of 90 cm, and this board material 1
As shown in FIG. 1, while being transferred by the conveyor 2, it is continuously pressurized with a linear pressure of 300 kg/cra by the roll 3.3, and then transferred to the second conveyor 4 disposed orthogonally to the conveyor 2, and then transferred again to the roll 3. Pressure was applied with the same linear pressure as above, and roll pressure was applied a total of one time in the vertical direction and one time in the horizontal direction.

Example 2 A cement mixture consisting of 40% by weight of cement, 57% by weight of aggregate such as silica, and 3% by weight of reinforcing valve fibers was mixed in a dry state and fed in a layer onto a molded heald moistened with water,
After further sprinkling water on the layer, it was leveled with a binker roll and a forming roll, and a plate material with a thickness of 4.5 mm was formed by a dry method.

The formed plate was transferred by a conveyor and continuously pressed with a linear pressure of 300 kg/cm by a pressure roll, and then cut into lengthwise pieces of 45 CIIS Ja 90 mm by a cutter, and this plate material was transferred to a second conveyor disposed orthogonally as in Example 1. Then, pressure was applied again using the pressure roll at the same linear pressure as above, and roll pressure was applied a total of countersunk times in the vertical direction and one time in the horizontal direction.

Comparative Example 1 In Example 1, the plate material was formed by only applying roll pressure in the first round without rotating the plate material 90''.

Comparative Example 2 In Example 2, the plate material was formed without rotating the plate material 90' (only by applying roll pressure in the first plate turn).

The plates obtained in Example 1.2 and Comparative Example 1.2 were both cured at room temperature for 12 hours, and then subjected to high temperature and high pressure air curing in an autoclave.

1 for JI No. 33 for 3 days old material! Accordingly, a bending test and a deflection test were conducted, and the results shown in Table 1 were obtained.

Table I JI No. 53 bending test As is clear from Table 1, the strength ratio of the length and breadth of the method of this invention is close to Pa1 in both Examples I and 2, and the difference in strength in the length and breadth is small compared to the comparative example. It has been found.

(Effects) As explained above, according to the method of the present invention, the bending strength of the plate material in the vertical direction and the horizontal direction are equal, and a plate material with no directionality and uniform strength can be obtained.

[Brief explanation of drawings]

FIG. 1 is a plan view of an apparatus for carrying out the method of the invention.

Claims (1)

[Claims] (1) Prior to curing and curing an uncured inorganic board formed from a cement mixture containing reinforcing fibers, the unhardened inorganic board is rolled and pressed in two directions 90 degrees apart in length and width. Method of manufacturing plate materials.