JPH09150410A - Manufacture of ceramic construction board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reuse generated cut chips by mixing the chips in large quantities into a raw material by cutting and trimming a mat prepd. by forming of a mixture of hydraulic raw materials contg. a cement, a silica fine powder and a reinforcing fiber material under a semi-cured condition and curing thereafter it completely by autoclave aging. SOLUTION: A mixture of raw materials contg. a Portland cement, a silica fine powder and a reinforcing fiber material is dispersed in water to make a slurry and a mat is formed by paper manufacturing way, suction and dehydration and after it is pressed, a plurality of sheets of the mats are piled and left as they are to perform the primary curing. The primarily cured mat is cut and trimed and the generated cut ships is ground to reuse it by mixing it into the mixture of the raw materials. After cutting and trimming processes, the mat is aged in an autoclave under heating to approximately completely cure it and coating and decoration are applied to prepare a product. Chips of the products generated in the final classification process are ground and reused by mixing them into a mixture of the raw materials.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a ceramic building board used as, for example, a roof material or an outer wall material.

[0002]

2. Description of the Related Art The above-mentioned ceramic-based building board is mainly composed of cement and a silicic acid component such as silica powder, and a reinforcing fiber material, and the demand for it as a roofing material or an outer wall material is recently increasing.
Conventionally, in order to manufacture the ceramic building board, a ceramic building board raw material containing a cement hydraulic material is molded into a mat, and the mat is cured and cured, and then cut to a predetermined size, and actual processing,
A method is applied in which cutting and trimming such as small piece processing and sanding processing is performed, and a product is obtained after a drying and painting step and a commercialization step. The cutting waste generated from the cutting and trimming step is about 7 to 8% by weight in the case of flat roof tiles, about 6 to 7% by weight in the case of outer wall materials, and 8 to 9 in the case of interior materials.
If the product waste generated from the commercialization process after the coating and makeup process is added to the weight%, the scrap material generated from the manufacturing process of the above ceramic-based building board is 12 to 15% by weight with respect to the raw material.
Also. Moreover, in addition to the scrap material generated from the manufacturing process of the above-mentioned ceramic-type building board, when dismantling the building in which this ceramic-type building board is used, the scrap material of a ceramic-type building board generate | occur | produces. Therefore, effective reuse of scrap materials and waste materials of the above ceramic building boards is desired, and at present, it is considered to use the scrap materials and waste materials by mixing them with ceramic building board raw materials (special features (Kaihei 4-238844, JP-A-5-208854).

[0003]

In the above-mentioned conventional means for reusing waste materials from ceramic-based building boards, a great amount of crushing energy is required because the cement hydraulic material in the waste materials is almost completely hardened. Since it is necessary and does not contribute to the curing of the product, a large amount of addition causes a decrease in the performance of the product, and there is a problem that only 10% by weight can be added to the raw materials for the ceramic construction board at the maximum. .

[0004]

[Means for Solving the Problems] As a means for solving the above-mentioned conventional problems, the present invention provides a mat obtained by forming a hydraulic raw material mixture containing cement, silica fine powder and a reinforcing fiber material in a semi-cured state. An object of the present invention is to provide a method for manufacturing a ceramic building board, which is subjected to cutting trimming and then completely cured by autoclave curing. In the present invention, the cutting waste generated in the cutting and trimming step is mixed with the raw material mixture for the mat and reused.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION As a raw material for a ceramic building board of the present invention, for example, Portland cement, or blast furnace cement obtained by mixing Portland cement with blast furnace slag, fly ash cement obtained by mixing fly ash, cement such as alumina cement, etc. Hydraulic materials such as silica powder, silica stone powder, silica fume, diatomaceous earth, silica fine powder such as clay, wood powder, wood wool, wood chips, wood fibers, wood pulp, wood fiber bundles and other wood reinforcing fiber material, Sepiolite,
A mixture of a reinforcing fiber material such as an inorganic reinforcing fiber material such as wollastonite and glass fiber, and a light aggregate such as pearlite, shirasu balloon, expanded shale, expanded clay, and coal waste, if desired, is used. In the raw material mixture, usually, cement is 28 to 40% by weight (hereinafter simply referred to as%), silica fine powder is 28 to 40%, and reinforcing fiber material is 5 to 40%.
When the lightweight aggregate is mixed, it is used in an amount of 3 to 10%.

In the present invention, the mat of the above raw material mixture is first formed. The mat is formed by a wet method of forming a mat by forming a slurry in which the above raw material mixture is dispersed in water, and forming on the template. There is a dry method in which the above raw material mixture is sprayed to form a mat. The mat formed as described above is pressed or pressed and conventionally heated and primary cured to be subjected to autoclave curing, but in the present invention, the primary curing is performed under non-heated and normal pressure, and the autoclave curing step is performed. Cutting trimming is performed before. In the primary curing step, the mats are stacked in a plurality of stages and semi-cured by leaving them in the closed room for 6 to 30 hours, and in the cutting and trimming step, the mat semi-cured by the primary curing step. To the specified size, for outer wall materials, the connecting end is actually processed, and for flat roof tiles, the corners etc. of the square mat are cut off to form polygonal or curved parts. For interior materials, the surface is sanded to make the thickness uniform. Since the mat is in a semi-cured state as described above, it is easy to cut and cut, and the cutting and trimming process can be easily performed. Although cutting scraps are generated from the cutting and trimming step, the amount thereof is about 7 to 8% in the case of a flat roof tile, about 6 to 7% in the case of an outer wall material, and an interior material as compared with the ceramic building material as described above. In the case of, it is 8-9%.

Following the cutting and trimming step, the semi-cured mat is heated and cured in an autoclave to be hardened almost completely. The conditions in the autoclave curing step are usually a curing temperature of 160 to 180 ° C. and a curing time of 6 to
15 hours. The mat, which has been almost completely cured by the autoclave curing step, is coated on its surface to be a product. Product waste such as a damaged plate or a defective surface plate is generated in the above-mentioned commercialization process. As described above, in the manufacturing process of the ceramic building board, two kinds of waste materials are generated: cutting scraps generated in the cutting and trimming process and product scraps generated in the commercialization process.

The above cutting waste is pulverized and mixed with the ceramic-based building board raw material for reuse, but since it is generated from the mat in a semi-cured state after the primary curing step under non-heated and normal pressure, the energy required for pulverization is Compared to the case of crushing completely hardened waste material, it is greatly reduced and it retains hydraulic property.Therefore, if it is reused by mixing it with the ceramic building board raw material mixture, the primary hardening process and autoclave curing are performed. In the process, it is hardened by the calcium silicate reaction together with the lime component and the silicic acid component in the raw material mixture and contributes to the strength development of the product. Therefore, the cutting waste can be added to the raw material mixture without deteriorating the performance of the product, and the amount of the product waste can be increased.

When mixed with the raw material mixture, the cutting waste is usually pulverized into a powder having a particle diameter of 1 mm or less, and the amount of the cutting waste added is usually 3 to 9% in the raw material mixture.
The above-mentioned product waste is also crushed and mixed with the ceramic-based building board raw material for reuse, but by adding the above-mentioned cutting waste, the limit addition amount of the product waste can be increased from the conventional 10% to 15%. .

Further, in the present invention, in addition to the above product scraps or in place of the above product scraps, a ceramic-based building board waste material generated by dismantling of a building is crushed and mixed with a ceramic-based building board raw material for reuse. Good. When mixing the above-mentioned product waste and / or ceramic-based building board waste material with ceramic-based building board raw materials, it is usually desirable to grind into powder of 1 mm or less.

The crushed material of the cutting waste generated before curing the autoclave and the crushed material of the product waste generated after the autoclave curing are each dispersed in water to form a slurry having a solid content of 10%, and a mat formed by papermaking suction dehydration is formed. After pressing by the surface pressure shown in Table 1, it was cured in an autoclave at 165 ° C. for 8 hours to be cured to prepare a plate-shaped sample. Table 1 shows the results of measuring the specific gravity and bending strength of the plate-shaped sample.

[Table 1]

As shown in Table 1, the bending strength is 19.2 MPa when a cutting pressure of 25.5 MPa is applied using cutting chips having a grain size of 1 mm or less, which is the same as that of a normal ceramic building board that does not use scrap materials or waste materials. Since the bending strength is about 30 MPa, it can be confirmed that the strength of the sample reaches about 64% of the strength of the ordinary ceramic construction board even if only the cutting waste is used. On the other hand, in the case of product waste, use a crushed product with a grain size of 1 mm or less to 25.5.
Even when a pressing pressure of MPa is applied, the strength of the sample reaches only about 34% of the strength of the ordinary ceramic construction board. Therefore, the cutting waste remains semi-hardened as described above, but the hydraulic property remains, but the product waste is almost completely hardened, and it is confirmed that the hydraulic property hardly remains.

[Examples 1 to 4 and Comparative Examples 1 to 4] Table 2
The raw material mixture having the composition shown in is dispersed in water to obtain a solid content of 10
% Of the slurry, the slurry is subjected to paper-making suction dewatering to form a mat, and the mat is pressed at a surface pressure shown in Table 2. Then, a plurality of the mats are stacked and placed in a closed chamber.
It is left to stand for 4 hours to be primary cured, and the cutting waste generated by cutting and trimming the primary cured mat in this way is 1
It is pulverized to a particle size of not more than mm and mixed and reused in the raw material mixtures of Examples and Comparative Examples in the amounts shown in Table 2. After the cutting and trimming process, the mat is cured in an autoclave at 165 ° C for 8 hours to be hardened almost completely, and the surface of the completely hardened mat is painted and made into a product, but the product waste generated in the final sorting process Is pulverized to a particle size of 1 mm or less and mixed with the raw material mixtures of Examples and Comparative Examples in the amounts shown in Table 2 and reused. Sample 1 of Examples 1 to 4 manufactured as described above
Table 4 shows the results of measuring various physical properties of Samples 5 to 8 of Comparative Examples 1 to 4 and Comparative Examples 1 to 4.

[0014]

[Table 2]

In Table 2, referring to Comparative Examples 1 to 3 in which cutting waste is not used, the sample 6 containing 10% of product waste has a bending strength substantially equal to that of the sample 5 containing neither cutting waste nor product waste. 70% and specific strength of about 76% are secured, but the bending strength of Sample 7 containing 15% of product waste is about 5 as compared with Sample 5.
It can be seen that the specific strength is 6% and the specific strength is about 67%.
On the other hand, in Examples 1 to 4 in which cutting waste was mixed, product waste was 15%.
The bending strength of the mixed sample 4 is about 62% as compared with the sample 5,
About 73% of the specific strength is secured. However, in Sample 8 of Comparative Example 4 in which 16% of product waste was mixed, even if 9% of cutting waste was mixed, the bending strength was reduced to 60% or less and the specific strength was decreased to 70% or less compared to Sample 5.

[Examples 5 to 10 and Comparative Examples 5 to 8] Examples 5 to 10 and Comparative Examples 5 to 8 relate to low specific gravity samples using lightweight aggregate. Using the raw material mixture having the composition shown in Table 3, Samples 9 to 18 were prepared in the same manner as in Examples 1 to 4 and Comparative Examples 1 to 4, and various physical properties were measured.

[0017]

[Table 3]

In Table 3, referring to Comparative Examples 5 to 7 in which cutting waste is not used, the sample 16 containing 10% product waste has a bending strength of approximately 10% as compared with the sample 15 containing neither cutting waste nor product waste. 70% and specific strength of about 78% are secured, but in the sample 17 in which 15% of product waste is mixed, the bending strength is decreased to about 52% and the specific strength is decreased to about 63% as compared with the sample 15. Recognize. On the other hand, in Examples 5 to 10 in which cutting scraps are mixed, even in Sample 12 containing 15% of product scraps, a bending strength of approximately 62% and a specific strength of approximately 73% are secured as compared with Sample 5. However, in the case of the sample 18 of the comparative example 8 in which the product waste was mixed by 16%, the bending strength was 55% as compared with the sample 15 even if the cutting waste was mixed by 9%.
Hereinafter, the specific strength decreases to 65% or less.

[0019]

Therefore, since the cutting waste generated by the present invention is in a semi-hardened state, it can be reused after being mixed with a large amount of the raw material for the ceramic construction board, and by adding the cutting waste, It is also possible to increase the amount of waste material mixed in the ceramic construction board without deteriorating the performance of the product.

[Procedure amendment]

[Submission date] May 17, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction contents]

In Table 3, referring to Comparative Examples 5 to 7 in which cutting waste is not used, Sample 16 containing 10% product waste does not include cutting waste and product waste.
The bending strength is about 70% and the specific strength is about 78% as compared with the sample No. 5, but the bending strength of the sample 17 containing 15% of product waste is about 52% and the specific strength is more than that of the sample 15. It can be seen that it has dropped to about 63%. On the other hand, in Examples 5 to 10 in which cutting waste was mixed, sample 12 containing 15% of product waste was mixed.
But flexural strength compared to Sample 15 approximately 60%, the specific strength is approximately
70% is ensured. However, in the case of the sample 18 of Comparative Example 8 in which the product waste was mixed by 16%, the sample 1 was mixed with the cutting waste by 9%.
Bending strength is 55% or less, and specific strength is 65% or less.

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Claims (2)

[Claims] 1. A ceramic system characterized in that a mat formed with a hydraulic raw material mixture containing cement, silica fine powder and a reinforcing fiber material is cut and trimmed in a semi-hardened state, and then completely cured by autoclave curing. Building board manufacturing method 2. The method for producing a ceramic building board according to claim 1, wherein the raw material mixture contains 3 to 9% by weight of cutting waste generated from the cutting and trimming step and 0 to 15% by weight of product waste.