JPH08207025A - Production of inorganic cement panel - Google Patents

Abstract

PURPOSE: To produce an inorg. cement panel having good deep carving uneven patterns without lowering productivity. CONSTITUTION: In a method for producing an inorg. cement panel by subjecting an aq. slurry based on cement, aggregate and a fiber component to papermaking processing to obtain a green sheet, upper and lower molds 1, 2 at least one of which has uneven patterns are arranged up and down within the aq. slurry and gradually clamped while the aq. slurry interposed between the upper and lower molds 1, 2 is dehydrated under reduced pressure and, thereafter, the upper and lower molds 1, 2 are released in pressure outside the aq. slurry to obtain a green sheet 6 having uneven patterns.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an inorganic cement board used as a ceramic exterior material, a roof tile material, an exterior member or the like.

[0002]

2. Description of the Related Art Conventionally, an aqueous slurry containing cement, aggregate, and fiber components as main components is formed into a green sheet, and the green sheet is press-molded to give an uneven pattern on the surface and then cured. It is then hardened to produce an inorganic cement board. Conventionally, in a papermaking process, an aqueous slurry is dehydrated under reduced pressure to form a green sheet having a solid content concentration of 63% by weight or more (water content of 60% by weight or less), and the green sheet is press-molded to form an uneven pattern on the surface. Granted.

[0003]

However, in the conventional method for producing an inorganic cement board, since the water content of the green sheet is low, the flowability of the inorganic material forming the green sheet is low, and the green sheet is press-molded. Then, when a deeply rugged uneven pattern having a large undulation is applied, there is a problem that cracks are generated in a tightly carved portion of the uneven pattern.

On the other hand, when the water content of the green sheet obtained in the papermaking process is increased to increase the fluidity of the inorganic material, it becomes possible to give a good deep rugged pattern. It is easy to lose its shape and the handleability deteriorates. Also, it is necessary to perform press molding for a long time so that the inorganic material does not leak out between the upper and lower molds during press molding, which lowers productivity. There was a problem.

The present invention has been made in view of the above circumstances, and provides a method for producing an inorganic cement board capable of imparting a good deep rugged pattern without lowering productivity. is there.

[0006]

A method for producing an inorganic cement board according to claim 1 is a method for producing an inorganic cement board for producing a green sheet by making an aqueous slurry containing cement, an aggregate and a fiber component as main components. In the method, an upper die and a lower die having a concavo-convex pattern on at least one side of the aqueous slurry are arranged vertically, and the aqueous slurry present between the upper and lower dies is dehydrated under reduced pressure and gradually tightened between the upper and lower dies. After pressing, the upper and lower molds are decompressed outside the aqueous slurry to obtain a green sheet having an uneven pattern.

A method for producing an inorganic cement board according to a second aspect is the method for producing an inorganic cement board according to the first aspect, wherein the lower die circulates inside and outside the aqueous slurry by means of a conveyor, and at the same time above this lower die. In addition, the upper mold is circulated in the inside and outside of the aqueous slurry by a conveyor in conjunction with the lower mold.

[0008]

According to the method for producing an inorganic cement board as set forth in claim 1, an aqueous slurry in which an upper die and a lower die having a concavo-convex pattern on at least one side are arranged vertically in the aqueous slurry and are interposed between the upper and lower dies. Since the upper and lower molds are gradually tightened and compressed while being dehydrated under reduced pressure, the aqueous slurry is dehydrated under reduced pressure while filling the space between the upper and lower molds and loses fluidity to form a green sheet. Therefore, this green sheet is in a state in which an uneven pattern is provided, and by further depressurizing the upper and lower molds outside the aqueous slurry, a green sheet having a good uneven pattern is obtained without cracks. Obtainable.

According to the method for producing an inorganic cement board according to claim 2, in the method for producing an inorganic cement board according to claim 1, the lower mold circulates inside and outside the aqueous slurry by means of a conveyor, and at the same time, above the lower mold. Since the upper die circulates inside and outside the aqueous slurry in conjunction with the lower die by the conveyor, it is possible to continuously produce a green sheet provided with a good uneven pattern, and the productivity is good. .

The present invention will be described in detail below. In the present invention, the aqueous slurry is mainly composed of an inorganic material composed of cement, aggregate and fiber component, and water is added thereto and mixed by stirring to have a solid content concentration of 50% by weight or less (water content is 100%).
% By weight). As the above cement, Portland cement, blast furnace cement, etc.,
Commonly used cement can be used.
The aggregate is not particularly limited and may be selected according to the intended use of the inorganic cement board, and commonly used mineral aggregates, inorganic aggregates, and organic aggregates are used. Examples thereof include silica stone powder, silica sand, silica, gravel, fly ash, perlite, glass balloons, and shirasu balloons. Further, the fiber component is not particularly limited, such as organic fiber, inorganic fiber, metal fiber, and, for example, pulp, cotton, hemp, vinylon (trademark), asbestos and the like can be used.

Further, in the present invention, press molding is started in the aqueous slurry and decompression is performed outside the aqueous slurry. That is, the upper die and the lower die are arranged in the aqueous slurry so as to face each other vertically and gradually tightened, and at the same time, the aqueous slurry present between the upper die and the lower die is dehydrated under reduced pressure. Then, the water content of the aqueous slurry decreases in a state where the space between the upper mold and the lower mold is filled, and gradually loses fluidity, and the inorganic material is solidified to form a green sheet.
At this time, the upper and lower molds may be clamped with an appropriate pressing pressure so that the shape of the green sheet is stable. Then, by depressurizing the upper and lower molds outside the aqueous slurry, a green sheet having a good uneven pattern without cracks on the surface can be obtained. In the present invention, only the depressurization of the upper and lower molds may be performed outside the aqueous slurry, or the upper and lower molds may be temporarily clamped in the aqueous slurry and then discharged outside the aqueous slurry in this state. After performing the clamping, the upper and lower molds may be depressurized. Here, the term "temporary compression" refers to a state in which the upper and lower molds have been closed and dehydration under reduced pressure has progressed to a certain extent, and the aqueous slurry between the upper and lower molds has become a substantially green sheet, and an uneven pattern is generally formed on the surface thereof. Is.

In the present invention, at least one of the upper mold and the lower mold is provided with an uneven pattern. The shape of this uneven pattern is not particularly limited, but the effect of the present invention becomes remarkable when it is a deeply uneven uneven pattern having large undulations. In addition, it is preferable that at least one of the upper mold and the lower mold is provided with a drain hole for draining water at the time of vacuum dehydration. In order to prevent the material from being clogged, a wash-out prevention layer such as felt may be provided on the mold surface.

In the method for producing an inorganic cement board according to the present invention, an inorganic cement board can be obtained by curing the obtained green sheet by curing, and the curing method is not particularly limited, and it is known. Can be used.

[0014]

Embodiments of the present invention will be described below. FIG. 1 is a side view showing a method of manufacturing an inorganic corner accessory according to an embodiment of the present invention. FIG. 2 is an enlarged side view of an essential part of the method for manufacturing the inorganic cement board shown in FIG.

In the method for manufacturing an inorganic cement board according to this embodiment, as shown in the figure, the lower mold 2 is vertically rotated and circulated by a lower conveyor 13 having a plurality of conveying rolls 4, and the lower mold 2 A plurality of transport rolls 3 so that they are interlocked upward
The upper mold 1 is vertically rotated and circulated by the upper conveyor 12 provided with the upper mold 1 and the lower mold 2 are the aqueous slurry 7
Are arranged so as to face each other in the aqueous slurry tank 70 filled with.

The lower conveyor 13 enters the aqueous slurry tank 70 from below and has a two-step upslope and conveys the lower mold 2 from the bottom to the top. In the two-stage upward gradient of the lower conveyor 13 in the aqueous slurry tank 70, the upper gradient is gentler than the lower gradient, and further, the lower conveyor 13 goes out of the aqueous slurry tank 70 and then The mold 2 is conveyed horizontally. Lower mold 2
Has a drainage hole 10 which has a smooth molding surface and penetrates from this molding surface to the back surface. A felt 8 is laid on the surface of the molding surface of the lower mold 2 and is conveyed integrally with the lower mold 2.

A vacuum dewatering machine 5 is provided on the lower surface of the lower conveyor 13 from the upper sloped portion to the horizontal portion so that excess water is removed from the aqueous slurry 7 through the drain holes 10 of the lower mold 2. It has become.

The upper conveyor 12 enters the aqueous slurry tank 70 from above and turns upward, and conveys the upper mold 1 along the upper slope of the lower conveyor 13 in the aqueous slurry tank 70. The upper mold 1 has a concavo-convex pattern on the molding surface, and has air holes 11 penetrating from the molding surface to the back surface. The concavo-convex pattern of the upper mold 1 is provided with a concave portion (convex portion) having a depth (height) of 10 mm and a width of 10 mm. The upper mold 1 faces the lower mold 2 in the upper sloping portion of the lower conveyor 13, and the interval between the upper mold 1 and the lower mold 2 becomes gradually narrower as it goes up along the slope. The temporary squeezing of the aqueous slurry 7 (green sheet 6) interposed between the upper mold 1 and the lower mold 2 in the aqueous slurry tank 70 is carried to the outside of the aqueous slurry tank 70, and is finally pressed. It has become.

Further, in the confronting portion of the upper mold 1 and the lower mold 2, the aqueous slurry 7 leaks from between the upper mold 1 and the lower mold 2 on both sides of the upper mold 1 and the lower mold 2. A side plate 9 for preventing the sticking out is provided.

The operating state of the manufacturing process in this embodiment will be described. First, as shown in FIG.
The aqueous slurry 7 interposed between the upper mold 1 and the lower mold 2 is
While being conveyed upward by the upper conveyor 12 and the lower conveyor 13 in a state in which the space between the lower mold 2 and the lower mold 2 is filled, excess water is dehydrated by the reduced pressure dehydrator 5 and fluidity is gradually lost, and at the same time, the upper mold is pressed from above and below. As it is clamped by the mold 1 and the lower mold 2 and comes out of the aqueous slurry tank 70, FIG.
As shown in (b), the green sheet 6 is formed by temporary compression. After that, as shown in FIG. 3C, the aqueous slurry tank 7
Outside 0, the pressing pressure of the upper mold 1 and the lower mold 2 is increased to perform final compression, and the green sheet 6 is solidified and its shape is stabilized.
Further, as shown in FIG. 3D, the lower mold 2 is the lower conveyor 1
The green sheet 6 is demolded from the upper mold 1 by releasing the pressure at the point where it is conveyed in the horizontal direction by 3 and simultaneously applying air pressure from the air holes 11 provided in the upper mold 1, and A green sheet 6 having a good uneven pattern is obtained.

Next, in Example 1 shown below, a green sheet provided with a concavo-convex pattern was produced in accordance with the above-mentioned production process, while in Comparative Examples 1 and 2, the green sheet was produced by the conventional production method. It was made.

Example 1 50% by weight of ordinary Portland cement, 25% by weight of silica stone powder, 19% by weight of silica sand (No. 6), pulp (NUK)
P) 6% by weight was mixed with an inorganic material to which water was added so that the solid content concentration was 20% by weight (water content was 400% by weight), and the mixture was stirred and mixed to prepare an aqueous slurry 7. The aqueous slurry 7 is filled in the aqueous slurry tank 70, the upper conveyor 12 and the lower conveyor 13 are operated, and the green is provided with a concavo-convex pattern by temporary pressing, main pressing, and demolding under the following conditions. Sheet 6 was manufactured. At this time, when the temporary compression is performed, the aqueous slurry 7 has a solid content concentration of 61% by weight (a water content of 6%).
(5% by weight) to form a green sheet 6, and dehydration under reduced pressure was carried out, and the pressing pressure at the time of temporary compression was 5 kg / cm ² . Further, the pressure was increased to 30 kg / cm ² from the state of this temporary compression in a pressure increase time of 20 seconds, and then the pressure was maintained for 5 seconds to perform the main compression. Molding oil is applied to the molding surface of the upper mold 1 in advance, and the mold is released by applying air pressure from the air holes 11 of the upper mold 1 to obtain a solid content concentration of 82% by weight (water content 22% by weight). The green sheet 6 of was obtained. No crack was observed in the uneven pattern of the green sheet 6.

Comparative Example 1 An aqueous slurry 7 prepared in the same manner as in Example 1 was made into paper by a fourdrinier papermaking method to prepare a green sheet having a solid content concentration of 63% by weight (water content 60% by weight). Is pressed between upper and lower molds having the same shapes as the upper mold 1 and the lower mold 2 in Example 1, and press-molded,
A green sheet having a solid content concentration of 79% by weight (water content of 27% by weight) and having an uneven pattern was obtained. Cracks were observed in the uneven pattern of this green sheet.

Comparative Example 2 An aqueous slurry 7 blended in the same manner as in Example 1 was made into paper by the Fourdrinier papermaking method to obtain an inorganic material having a lower solid content concentration (higher water content) than that of Comparative Example 1. A green sheet having fluidity was produced, and this green sheet was pressed slowly between the same upper and lower molds as in Comparative Example 1 and press-molded so that the inorganic material did not leak out between the upper and lower molds. Although no cracks were found in the uneven pattern of the green sheet, it took about 30% extra time to manufacture the green sheet.

From the results of producing the green sheets in Example 1, Comparative Example 1 and Comparative Example 2, in Example 1, the obtained green sheet was free from cracks as in Comparative Example 1 and the Comparative Examples The productivity did not decrease as in 2. Therefore, in Example 1, it is possible to manufacture an inorganic cement board provided with a good deep rugged pattern without lowering productivity.

[0026]

According to the method for producing an inorganic cement board according to the first aspect, an upper mold and a lower mold having an uneven pattern on at least one side are arranged vertically in an aqueous slurry, and are interposed between the upper and lower molds. Since the upper and lower molds are gradually tightened and pressed while dehydrating the aqueous slurry under reduced pressure, the aqueous slurry is dehydrated under reduced pressure while filling the space between the upper and lower molds to lose fluidity and form a green sheet. Therefore, this green sheet is in a state in which an uneven pattern is provided, and by further depressurizing the upper and lower molds outside the aqueous slurry, a green sheet having a good uneven pattern is obtained without cracks. Obtainable.

According to the method for producing an inorganic cement board according to claim 2, in the method for producing an inorganic cement board according to claim 1, the lower mold circulates inside and outside the aqueous slurry by means of a conveyor, and at the same time, above the lower mold. Since the upper die circulates inside and outside the aqueous slurry in conjunction with the lower die by the conveyor, it is possible to continuously produce a green sheet provided with a good uneven pattern, and the productivity is good. .

[Brief description of drawings]

FIG. 1 is a side view showing a method of manufacturing an inorganic corner accessory according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of an essential part of the method for manufacturing the inorganic cement board shown in FIG.

3 (a), (b), (c), and (d) sequentially show steps of a method for producing an inorganic cement board according to an embodiment of the present invention, and (a) is a sectional view taken along line AA of FIG. And (b) is shown in FIG.
2B is a cross-sectional view taken along the line BB of FIG. 1, FIG. 3C is a cross-sectional view taken along the line CC of FIG. 1, and FIG.

[Explanation of symbols]

 1 Upper mold 2 Lower mold 5 Vacuum dewatering machine 6 Green sheet 7 Aqueous slurry 12 Upper conveyor 13 Lower conveyor

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C04B 111: 00

Claims (2)

[Claims] 1. A method for producing an inorganic cement board for producing a green sheet by making an aqueous slurry containing cement, an aggregate and a fiber component as main components, in a method for producing an inorganic cement plate, wherein at least one of the aqueous slurry has an uneven pattern. The upper and lower molds are arranged vertically, and the aqueous slurry interposed between the upper and lower molds is dehydrated under reduced pressure, and the upper and lower molds are gradually tightened and compressed, and then the upper and lower molds are decompressed outside the aqueous slurry to produce unevenness. A method for producing an inorganic cement board, which comprises obtaining a green sheet having a pattern. 2. The lower mold is circulated inside and outside the aqueous slurry by a conveyor, and at the same time, the upper mold is circulated inside and outside the aqueous slurry by a conveyor in conjunction with the lower mold above the lower mold. The method for producing an inorganic cement board according to claim 1.