JP2003300767A - Inorganic board and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic board and a manufacturing method therefor realizing an improvement in the water permeability resistance of an inorganic board product without applying excess coating and an improvement in its productivity as the inorganic board obtained by spraying a surface layer raw material on the surface of a base layer mat, and a manufacturing method therefor. <P>SOLUTION: In the inorganic board and the manufacturing method therefor, slurry having cement and a reinforcing fiber material as major components is caused to flow down in a form placed on a water permeable sheet and dehydrated to form a base layer, and a powdery mixture having the cement and the reinforcing fiber material as major part is sprayed and layered on the surface of the base layer, and dehydrated, aged and hardened to obtain the inorganic board. In such a case, the powdery raw material mixture in the surface layer contains flyash, an inorganic board recycled raw material and the reinforcing fiber material composed of short fibers and is sprayed and layered on the base layer. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic plate used as a building material such as an outer wall material and a roof material, and a method for manufacturing the same.

[0002]

2. Description of the Related Art An inorganic plate of this type is prepared by dispersing a raw material mixture mainly composed of a hydraulic material such as cement and a reinforcing fiber substance such as pulp in water to form a slurry, and then mixing the raw material mixture on a water-permeable sheet. Is made to flow into a mat shape, dehydrated by a press machine, cured, and dried. These inorganic plates are manufactured by integrally molding a flat plate without a pattern and sometimes an uncured plate having a real part by dehydrating and molding an uncured mat with a press machine. In addition to this method, an embossed pattern is provided on the surface of the inorganic plate in order to give a three-dimensional change. In order to give this embossed pattern, when the mat is pressed and dehydrated, a press machine equipped with a template with a pattern formed on the surface is used. The conventional method is generally used, and various pattern patterns are applied to the inorganic plate.

Recently, in order to obtain a deep embossed pattern on the surface of an inorganic plate, a raw material mixture mainly composed of a hydraulic material such as cement and a reinforcing fiber substance such as pulp is dispersed in water to form a slurry. There is provided a multi-layer type inorganic plate which is sprayed in a layered manner on a water-permeable sheet, and then a raw material mixture having a different composition is further sprayed on the upper surface thereof in a layered manner and press-formed. As a method for obtaining such a deep embossed pattern, a powder material in which a surface layer material has a water content of 40% or less and a lightweight aggregate is blended in a specific range is spray-laminated and pressed to form a deep surface. Embossed patterns are used. (JP-A 61-149312)
In addition, in order to make the product surface smooth and dense, as a method of spreading the powder material on the surface raw material, the surface layer is made dense by spraying powder cement with a small particle size and then pressing. The method of doing is taken. (JP-A 6-1
90818)

[0004]

However, according to the above-mentioned conventional example, an embossed pattern having a certain depth can be applied to the surface of an uncured inorganic plate by using a press, but the raw material used for the surface layer is Since the water content is low and the fluidity is insufficient, it corresponds to the part that constitutes the convex part of the inorganic plate at the time of pressing, especially when molding with a press machine with a template with an embossed pattern formed on the surface It is difficult for the raw material to move to the concave portions of the embossed pattern template, and the surface has a low specific gravity, so that porous portions are likely to occur.
Further, when the slurry is flowed down into the mold placed on the water-permeable sheet to form the base layer, and when the surface layer is further sprayed on the base layer, the spray raw materials are not uniformly mixed and flocs remain. During spraying, uneven spraying is likely to occur in the plate, and a portion thinner than usual is likely to be porous. As a result, after pressing, a pinhole, a so-called burrow, is generated on the surface of this porous portion, and this burrow deteriorates the surface quality of the inorganic plate,
Water absorption from it becomes easy. If the inorganic plate is used as the outer wall material, water tends to be absorbed into the burrows due to rainfall or the like, which adversely affects the water permeation resistance of the inorganic plate. Also, this burrow not only reduces the compactness and design of the surface of the inorganic plate, but also cracks occur on the plate surface due to expansion and contraction of the inorganic plate due to repeated water absorption drying, and freeze-thaw resistance deteriorates. , The durability of the product was significantly deteriorated.

In order to eliminate these burrows, a measure has been taken to improve the fluidity at the time of press molding by containing a large amount of water in the powder raw material of the surface layer. If mixed with, the reinforcing fiber material is relatively long fibers and easily aggregates in a ball shape, and since it is a non-uniform mixture, it takes time to dehydrate during molding, resulting in partial dehydration failure. However, there has been a problem that the surface property of that portion is lowered and the productivity is lowered. In addition, although a means of improving water resistance by coating the surface of the inorganic plate is taken, a certain amount of coating is required to completely hide the burrows, improving the water resistance of the product. However, there was a problem in that the coating cost would increase.

Further, in order to make the surface of the product dense, a means for further dispersing a powder material having a small particle diameter such as powder cement on the surface layer raw material is taken, but the raw material having a small particle diameter is used as the surface layer. Since it is sprayed, it is easy for fine powder material to adhere to the surface of the template after molding, which will rather deteriorate the surface properties of the molded product, and new equipment is required to spray raw materials with a small particle size. Therefore, the manufacturing equipment becomes large-scaled, and there is a problem that the manufacturing cost is increased.

Further, since the powder raw material mixture for the surface layer lacks bulkiness, it is not possible to secure a sufficient amount for spraying on the base layer, and the base layer is likely to appear on the surface, resulting in poor dehydration only in that part. There is a drawback that holes are likely to occur. In order to avoid this, a method of spreading and laminating a large amount of surface layer raw material on the base layer can be taken, but due to the different expansion and contraction rates of the base layer and the surface layer, warpage occurs when the inorganic plate is used for a long period of time. There was a problem that

On the other hand, in the method of manufacturing an inorganic plate using a mold, when the press speed is increased to improve the production efficiency, the slurry is ejected from the gap between the mold and the press, or water is sprayed on the surface after the press. As a result, the design property of the product surface is deteriorated and the press speed cannot be increased so much. In order to solve this, until now, although a means for increasing the pressing speed has been adopted by decreasing the water content of the surface layer raw material so that the water content of the base layer slurry is easily absorbed by the surface layer, the surface layer raw material has been adopted. Since there is no water-absorbing hole for sufficiently absorbing the water in the base layer slurry, there is a certain limit in improving the productivity of the inorganic plate in the mold pressing method. That is, it has been an important issue in terms of the character of the product to improve the productivity of the inorganic plate so far, and to cause the surface of the inorganic plate to have no densities of smoothness and denseness, and particularly to improve the water permeation resistance of the inorganic plate. there were. The present invention has been made in order to solve the above problems, in the inorganic plate obtained by spraying the surface layer raw material on the surface of the base layer mat and press dehydration molding and its manufacturing method, without applying excessive coating It is an object of the present invention to provide an inorganic plate that improves the surface property of a plate product and improves productivity, and a method for manufacturing the same.

[0009]

In order to achieve the above object, the present invention relates to a first aspect of the present invention, wherein a slurry containing cement and a reinforcing fiber material as main components is placed in a formwork placed on a water permeable sheet. An inorganic plate obtained by performing dehydration and then curing to form a base layer, spraying and laminating a powder mixture containing cement and a reinforcing fiber substance as a main component on the upper surface of the base layer, and dehydrating and curing. The powder mixture contains fly ash, a recycled material for an inorganic plate, and a reinforcing fiber material of short fibers, to provide an inorganic plate.
According to the above configuration, fly ash, an inorganic plate recycled raw material, and a reinforcing fiber substance of short fibers are contained in a bulky state and are easily dispersed, so that the surface layer containing these raw materials has a high compression pressure. In addition, when the embossed pattern is pressed, the raw material easily moves to the concave part of the template having the embossed pattern on the surface, so that the surface layer material becomes dense and there is no pitted inorganic plate. Becomes Further, since these raw materials are bulky and the fibrous substance is short fibers, they are easily dispersed during mixing, and the fibers do not become entangled with each other to form a fiber ball. As a result, there is no unevenness in the application of the powder raw material, so that the surface of the inorganic plate has no cavities. In addition, since the surface layer becomes a raw material with increased dehydration pores due to its bulkiness,
It becomes easier to absorb water in the base layer slurry, and the inorganic plate has excellent productivity.

According to the second aspect of the present invention, a slurry containing cement and a reinforcing fiber material as main components is made to flow into a mold placed on a water-permeable sheet and then dehydrated to form a base layer. A method for producing an inorganic plate, in which a powder mixture containing cement and a reinforcing fiber substance as main components is sprayed and laminated on the upper surface and cured by curing after dehydration molding, which is a fly ash, a recycled material for an inorganic plate, and a reinforcing fiber substance for short fibers. The present invention provides a method for producing an inorganic plate, characterized in that the powder mixture containing and is dispersed and laminated on a base layer. According to the above configuration, since fly ash, a recycled raw material for an inorganic plate, and a reinforcing fiber substance of short fibers are contained and made bulky, a high pressing pressure is uniformly applied to the surface layer, and an embossed pattern is also formed. At the time of press molding, the raw material easily moves to the concave portion of the template having the embossed pattern, so that the surface layer material becomes dense and it is possible to easily manufacture the inorganic plate having no cavities. Further, since the surface layer raw material is bulky and the fiber-reinforcing substance is a short fiber, it can be easily dispersed during mixing, and a uniform raw material can be prepared. When this is sprinkled in the mold, the thickness can be made extremely uniform, so that it is possible to easily manufacture an inorganic plate without burrows. Further, since the base layer becomes a raw material whose dehydration pores are increased due to its bulkiness, it becomes easier to absorb water in the base layer slurry, and the inorganic plate can be manufactured with high productivity.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below. The inorganic plate according to the present invention is composed of a base layer and a surface layer, and a slurry in which a raw material mixture mainly composed of a hydraulic material such as cement and a reinforcing fiber substance such as pulp is dispersed in water is layered on a water-permeable sheet. The base material is a mat that flows down and is dehydrated to form a base layer, and on top of that, a raw material is prepared by layering a powder raw material mixture of a different composition mainly composed of a hydraulic material such as cement and a reinforcing fiber substance such as pulp in a surface layer. And an inorganic plate obtained by press dehydration molding. Here, examples of the hydraulic material include Portland cement, blast furnace slag cement, silica cement, fly ash cement, and alumina cement. As the reinforcing fiber substance, for example, wood chips, wood pulp, wood fiber bundles, wood wool, wood powder, synthetic fibers, etc. are used, but polyester fibers, polyamide fibers, acrylic fibers, polyvinylidene chloride fibers, acetate fibers, etc. Other organic fibers or inorganic fibers such as sepiolite, wollastonite, and glass fibers may be used.

Further, in the present invention, in addition to the above components, for example, silica gel, silica stone powder, silica fume, blast furnace slag, fly ash, silas balloon, perlite, bentonite, inorganic fillers such as silicic acid-containing substances such as diatomaceous earth, Anhydrous or crystallized chloride such as calcium chloride, magnesium chloride, iron chloride, aluminum chloride, sodium chloride, potassium chloride, lithium chloride, aluminum sulfate, alum, iron sulfate, lithium sulfate, sodium sulfate, potassium sulfate, magnesium sulfate Anhydrous or crystallized product of sulfate, etc., nitrate such as calcium nitrate, calcium nitrite, inorganic compound or crystallized product of nitrite, formate such as calcium formate, calcium acetate, anhydride or crystallized product of acetate, aluminate Cement hardening accelerator for soda, water glass, etc. Waxes, paraffins, water repellent agents such as silicon, expandable thermoplastic plastic beads such as foamed polystyrene beads may be added.

In order to produce the inorganic plate of the present invention, the mixture of the above raw materials is dispersed in water to form a slurry, and the slurry is supplied onto a water-permeable sheet and suction-dehydrated from the back surface of the sheet to form a mat. A method is adopted in which the powder raw material is sprinkled in layers on the upper surface, press-dehydrated and then cured and cured. Cements and silicic acid-containing substances are preferably used as raw materials used for the base layer of the inorganic hardened layer, and the total amount of the cements and the silicic acid-containing substance is 60 to 95 wt% in the base layer raw material. And the ratio of the cements to the silicic acid-containing substance is usually 70:30 to 30:70 by weight. The reinforcing fiber substance dispersed in the base layer raw material is usually 5% in the raw material.
It is added in an amount of ˜15% by weight, and when synthetic fibers are added, it is usually added in an amount of 5% by weight or less in the raw material. The silicic acid-containing substance allows the inorganic plate to be smoothly and completely cured by the reaction between cement and calcium silicate, and the dimensional stability of the obtained product is improved.

Further, when the lightweight aggregate is added, the lightweight aggregate is usually 1 to 15% by weight in the raw material, and when the inorganic plate recycling raw material is added, the normal aggregate is 1 to 20% by weight, It is desirable to use the ones listed below. These raw materials are desirable raw materials to be used because they reduce the weight of the inorganic plate to be produced and make the slurry bulky, but when the content exceeds the required amount in the mixture, the specific gravity is lowered and the reinforcing fiber substance is used. The strength of the inorganic plate obtained by the aggregation of is likely to decrease.

On the other hand, the surface layer of the inorganic hardened layer is a semi-dry powder raw material mixture to which a small amount of water is added, and is formed on the upper surface of the base layer. Similar to the base layer, the surface layer is mainly composed of cements and reinforcing fiber substances, desirably the cements and the silicic acid-containing substance are used, and the total amount of the cements and silicic acid-containing substance is 60 to 95% by weight. %
And the ratio of the cements to the silicic acid-containing substance is usually 70:30 to 30: 7 by weight.
It is set to 0. Further, in the present invention, it is essential that the powder raw material mixture contains fly ash, an inorganic plate recycling raw material, and a reinforcing fiber substance of short fibers, and the fly ash is usually contained in the raw material in an amount of 1 to 24% by weight. It is preferable that the recycled raw material of the inorganic plate is 1 to 30% by weight, and the reinforcing fiber substance of the short fiber to be dispersed is 1 to 10% by weight.
Regarding the amount of each of the base layer and the surface layer, the base layer slurry is 70 to 95% of the total solid content, and the surface layer powder raw material is 5 to 30%.
It is desirable to set it as%. Here, the bulk specific gravity of fly ash is preferably 0.5 to 1.4 g / cm3, and in order to improve the bulkiness, a bulk specific gravity of approximately 0.5 to 0.8 g / cm3 is desirable. The fiber length of the reinforcing fiber material is preferably 0.1 to 1.0 mm for wood pulp and 2.0 to 4.5 mm for synthetic fiber. At this time, the above-mentioned blending amount is used for the following reason. That is, if the blending amounts of fly ash and the inorganic recycle raw material are too small, the bulkiness cannot be exhibited, and the dispersibility during mixing deteriorates. Therefore, it becomes difficult to disperse uniformly on the base layer, and the high clamping pressure is not evenly applied to the surface layer at the time of press molding, and the inorganic plate is likely to have burrows. Further, if the blending amount of fly ash and the inorganic recycle raw material is too large, the specific gravity is lowered and the strength is likely to be lowered. On the other hand, if the amount of the reinforcing fiber substance of the short fiber is too small, the strength will be reduced because there are few fibers to be bonded to the cement, and if the amount of the reinforcing fiber substance of the short fiber is too large. However, since many fibrous substances appear on the surface, the water permeation resistance deteriorates.

The reason why the fiber length of the reinforcing fiber material is set as above is as follows. That is, if it is a reinforcing fiber of long fibers, it is difficult to uniformly disperse with a hydraulic material such as cement during mixing, and in addition to the phenomenon that some fibers float, fiber is entangled with each other to form a fiber ball. Therefore, when the raw material is sprinkled in the mold, the thickness cannot be made uniform, and the inorganic plate is likely to have burrows.

Next, the facility for manufacturing the inorganic plate according to the present invention will be described. As shown in FIG. 2, the manufacturing facility comprises a base layer slurry pouring device 2, a surface layer powder sprinkling device 3, a pressing dehydration molding device 4, a movable water permeable sheet 5, a suction dehydration device 8, a conveyor belt 9 and the like. ing. That is, the base layer slurry pouring device 2 is provided with a slurry storage tank 21, the surface layer powder spraying device 3 is provided with a powder mixture storage tank 22, and the suction dewatering device 8 is provided with a suction machine. There is. On the other hand, the press dehydrator 4 has a press 51, and the press 51 includes an upper plate 52 and a lower plate 54. Here, the lower plate 54 is equipped with a suction dehydrator and is fixed to the main body of the press 51, while the upper plate 52 is fixed with an embossed mold plate 53 having a pattern formed on the surface thereof, which can be driven up and down. Supported by. A water-permeable sheet 5 is rotatably stretched around the slurry pouring device 2, the surface-layer powder-dispersing device 3, the pressing dehydration molding device 4, and the suction dehydration device 8 in order. A conveyor belt 9 is stretched in the vicinity of to be rotatably driven.

The base layer raw material is usually made into a slurry by adding and mixing water so that the water content is 300 to 400%. The kneaded slurry is poured into a mold 10 placed on a mesh-shaped water permeable sheet 5 in a predetermined amount and supplied, and after the slurry is leveled, a suction dehydrator 8 is applied from the back surface of the water permeable sheet.
The suction device is driven to suck and dehydrate from the lower surface of the slurry. After dehydration, the water content of the slurry has been reduced to such a degree that the shape is maintained, and the water content is usually 150 to 200%.
The flat-plate mat 11 is formed in the mold. afterwards,
The water permeable sheet 5 is rotated and transferred to the vicinity of the surface layer raw material spraying device 3, and the powder raw material 12 is uniformly sprayed on the base layer mat. Here, it is desirable that the application rate of the powder raw material is 5 to 30% by weight based on the solid content of the base material. After spraying the surface layer, the mold 10 is removed and only the mat is left on the water permeable sheet, and the water permeable sheet 5 is rotatively moved to transfer the mat to the vicinity of the press dehydration molding device 4, and then on the press dehydration molding device. The upper plate is lowered by a predetermined stroke while being positioned between the plate 52 and the lower plate 54. By pressing with such a press dehydration molding apparatus, it is dehydrated and molded into a plate shape, and if desired, a pattern is attached to the mat surface by the template 53 fixed to the upper plate. The inorganic plate manufactured in this way is transferred to a curing step and hardened, but is cut into a predetermined size before or after the curing. For curing, the mat is usually left unheated or left under heating and atmospheric pressure for 6 to 30 hours in a closed chamber for primary curing, and then usually 160 to 180.
A two-stage curing method is used in which autoclave curing is performed at 6 ° C. for 6 to 15 hours to completely cure. After curing and curing, the cured mat is subjected to trimming, painting, etc., if desired, to give an inorganic plate product.

[0019]

EXAMPLES Examples of the present invention will be described below. Example 1 A raw material mixture having the following composition is prepared as a raw material for a base layer. 40% by weight of Portland cement, 39% by weight of silica stone powder,
Perlite 6.7% by weight, inorganic plate recycled raw material 6.
7% by weight, 6.7% by weight of pulp, and 1% by weight of synthetic fiber. The above raw material mixture is mixed with water and uniformly stirred to adjust the slurry to have a water content of 300%. The raw material slurry is poured into a mold placed on a water permeable sheet, leveled, and dehydrated for a certain period of time by a suction dehydrator installed on the lower surface of the water permeable sheet so that the water content of the slurry is 150%.

On the other hand, a raw material mixture having the following composition is prepared as a surface layer raw material. 32% by weight of Portland cement, 32% by weight of silica stone powder, 10% by weight of fly ash, 7% by weight of pearlite, 15% by weight of recycled inorganic plate, 3% by weight of pulp (fiber length 0.5 mm), 1% by weight of synthetic fiber
(Fiber length is 4 mm) and water is added so that the water content is 20% to obtain a powder raw material. Then, 25% of this powder raw material is dispersed on the base layer with respect to the total solid content, and this is subjected to pressure dehydration molding with a pressing device equipped with a template having a pattern pattern on the surface so as to have a set thickness . The mat thus molded is subjected to primary curing at 60 to 80 ° C. for 6 to 30 hours and secondary curing at 160 to 180 ° C. for 6 to 15 hours in an autoclave to obtain a predetermined inorganic plate.

Example 2 The composition of the surface layer raw material is adjusted as follows. A powder raw material is obtained with 32% by weight of Portland cement, 32% by weight of silica stone powder, 10% by weight of fly ash, 7% by weight of perlite, 15% by weight of a recycled raw material of an inorganic plate and 4% by weight of pulp (fiber length 0.5 mm). Others are the same as the conditions used in Example 1, and an inorganic board is manufactured.

Comparative Example 1 A raw material mixture having the following composition is prepared as a surface layer raw material. 42% by weight of Portland cement, 42% by weight of silica stone powder,
Perlite 7% by weight, inorganic plate recycled material 5% by weight, pulp 3% by weight (fiber length 2.5 mm), synthetic fiber 1% by weight (fiber length 6 mm) to obtain a powder material. Others are the same as that used in Example 1, and an inorganic board is manufactured. Comparative Example 2 A raw material mixture having the following composition is prepared as a surface layer raw material. Portland cement 37% by weight, silica stone powder 37% by weight,
10% by weight of fly ash, 7% by weight of perlite, 5% by weight of recycled inorganic plate material, 3% by weight of pulp (fiber length 2.5 mm) and 1% by weight of synthetic fiber (fiber length 6 mm) to obtain a powder material. Others are the same as that used in Example 1, and an inorganic board is manufactured. Comparative Example 3 A raw material mixture having the following composition is prepared as a raw material for the surface layer. Portland cement 37% by weight, silica stone powder 37% by weight,
Perlite 7% by weight, inorganic plate recycled material 15% by weight, pulp 3% by weight (fiber length 2.5 mm), synthetic fiber 1% by weight (fiber length 6 mm) to obtain a powder material. Others are the same as that used in Example 1, and an inorganic board is manufactured. Comparative Example 4 A raw material mixture having the following composition is prepared as a surface layer raw material. 42% by weight of Portland cement, 42% by weight of silica stone powder,
Perlite 7% by weight, inorganic plate recycled raw material 5% by weight, pulp 3% by weight (fiber length 0.5 mm), synthetic fiber 1% by weight (fiber length 6 mm) to obtain a powder raw material. Others are the same as that used in Example 1, and an inorganic board is manufactured. Comparative Example 5 A raw material mixture having the following composition is prepared as a raw material for the surface layer. 42% by weight of Portland cement, 42% by weight of silica stone powder,
Perlite 7% by weight, inorganic plate recycled material 5% by weight, pulp 3% by weight (fiber length 0.5 mm), synthetic fiber 1% by weight (fiber length 4 mm) to obtain a powder material. Others are the same as that used in Example 1, and an inorganic board is manufactured. Comparative Example 6 A raw material mixture having the following composition is prepared as a raw material for the surface layer. 32% by weight of Portland cement, 32% by weight of silica stone,
Fly ash 25% by weight, perlite 7% by weight, pulp 3% by weight (fiber length 0.5 mm), synthetic fiber 1% by weight (fiber length 4 mm) to obtain a powder raw material. Others are the same as that used in Example 1, and an inorganic board is manufactured.

The various inorganic plates thus obtained (Examples 1 and 2 and Comparative Examples 1 to 6) were confirmed for surface dispersion variation, surface properties, strength, brittleness, productivity and freeze-thaw resistance. . The results are shown in Table 1. Each evaluation was performed as follows. In other words, the surface layer dispersion variation is the ratio of surface layer dispersion within the plate, the surface quality is the appearance evaluation and the number of pinholes per square meter, and the strength is the bending strength of the surface layer material. The production time (sec) when manufacturing the product is JIS A 143
According to item 5, the appearance of the surface was observed after 200 cycles, and the measurement was performed.

[Table 1]

As is clear from Table 1, the inorganic plate obtained as in Example 1 can be provided with an embossed pattern having a dense surface and no burrows. Further, since the surface layer raw material becomes bulky and the dehydration holes increase, drainage can be improved and an inorganic plate can be produced with good productivity. In addition, since the surface layer raw material does not cause flocs, the surface layer can be scattered and laminated to a uniform thickness, so it is possible to manufacture an inorganic plate with good surface properties, improving the design of the product surface and the durability of the product. Can be made. Further, also in Example 2, it is possible to similarly obtain an inorganic plate having improved surface properties and productivity.

[0025]

Therefore, according to the present invention, the raw material forming the surface layer becomes bulky and the pressure at the time of pressing becomes high. Therefore, when press-molding the embossed pattern, the raw material is formed in the concave portion of the template having the embossed pattern. Becomes easy to move, the surface layer material becomes dense and becomes an inorganic plate with no cavities. Further, since the surface layer raw material becomes bulky, it is easily dispersed at the time of mixing to form a uniform slurry, so the surface layer material is dispersed in a uniform thickness,
It is possible to manufacture an inorganic plate having a good surface property. In addition, since the surface layer becomes a material in which the dehydration pores are increased due to the bulkiness, it becomes easier to absorb the water in the base layer slurry and the productivity can be improved.

[Brief description of drawings]

FIG. 1 (A) is a sectional view of a mat of an inorganic plate of the present invention before pressure dehydration molding. (B) A cross-sectional view of a conventional inorganic plate before press dehydration molding.

FIG. 2 is a side view showing a facility for manufacturing an inorganic plate according to the present invention.

FIG. 3 is a perspective view of a conventional product.

[Explanation of symbols]

2 Underlayer slurry pouring device 3 Surface powder disperser 4 Press dehydration molding device 5 Water-permeable sheet 6 cleaning equipment 7 Wastewater storage receiver 8 Suction dehydrator 9 Conveyor belt 10 Formwork 11 Base layer mat 12 Surface powder raw material 21 Base layer slurry storage tank 22 Surface powder mixture storage tank 51 Press 52 Upper board 53 template 54 Lower plate

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C04B 14:38 C04B 14:38 Z 18:08 18:08 Z 18:16 18:16 16:06 16: 06 A 16:02 16:02 Z 16:06) 16:06 EF term (reference) 4G012 PA22 PA27 PA30 PE06 4G052 AB30 AB42 4G054 AA01 AA15 AA20 AB01 BA00 BA02 BA24 BA27 BA62

Claims (2)

[Claims] 1. A slurry containing cement and a reinforcing fiber material as main components is made to flow down into a mold placed on a water-permeable sheet and then dehydrated to form a base layer, and the cement and the reinforcement are reinforced on the upper surface of the base layer. An inorganic plate obtained by spraying and laminating a powder mixture containing a fibrous material as a main component, dehydration molding and curing and curing, wherein the powder mixture is fly ash, a recycled material for the inorganic plate, and a reinforcing fiber substance for short fibers. An inorganic plate characterized by containing and. 2. A slurry containing cement and a reinforcing fiber substance as main components is made to flow down into a mold placed on a water-permeable sheet and then dehydrated to form a base layer, and the cement and the reinforcement are reinforced on the upper surface of the base layer. A method for producing an inorganic plate in which a powder mixture containing a fibrous substance as a main component is sprayed and laminated, and dehydration-molding is followed by curing and curing, wherein fly ash, an inorganic plate recycling raw material, and a reinforcing fiber substance of short fibers are contained. A method for producing an inorganic plate, which comprises spattering and laminating the powder mixture on a base layer.