JP3480657B2 - Method for producing inorganic molded plate - Google Patents

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 an inorganic molded plate by press molding a laminated inorganic mat having a three-layer structure.

[0002]

2. Description of the Related Art In recent years, an inorganic molded plate has been widely used as a housing exterior material or roof material. The method for producing this inorganic molded plate is as follows. A molding raw material in which cement and fibers are mixed is used to mold an inorganic mat by a wet method (papermaking method) or a dry method, and this is press-molded to form an uneven pattern on the surface. A certain inorganic molded plate is molded. In order to press-mold a highly carved deep concave-convex pattern, it is necessary to increase the thickness of the inorganic mat, and it is also desired to improve the strength of the inorganic molded plate from the viewpoint of improving durability.

Therefore, as disclosed in JP-A-4-364902, it has been proposed to press-mold a laminated inorganic mat having a three-layer structure to produce an inorganic molded plate. In the method for producing a laminated inorganic mat of this publication, a cement slurry containing reinforcing fibers is supplied in layers on a molding belt to form a back surface layer, and a dried cement composition is supplied in layers on the upper surface of the back surface layer. To form an intermediate layer, and further, on the upper surface of this intermediate layer, similarly to the back layer, cement cement containing reinforcing fibers is supplied in layers to form a surface layer to form a three-layer laminated inorganic mat. I have to.

[0004]

In the above-mentioned method for forming a laminated inorganic mat, both the back layer and the surface layer are formed of cement slurry, so that it is necessary to dehydrate both the back layer and the surface layer. The back side cement slurry can be dehydrated through the forming belt, but the surface layer cement slurry is difficult to dehydrate through the forming belt, so the surface layer cement slurry contains moisture in the middle layer dry cement formulation. Only a small amount of the surface layer can be supplied, and the thickness of the surface layer becomes extremely thin. Further, when the amount of the dry cement mixture in the intermediate layer is increased, the amount of water necessary for wetting the dry cement mixture also increases, but when the amount of the cement slurry in the surface layer is increased to secure this amount of water, the cement slurry is increased. Flows out from the middle layer. Therefore, the dry cement composition of the intermediate layer cannot be increased too much, and the intermediate layer also becomes thin. As a result, the overall thickness of the laminated inorganic mat becomes thin,
Concavo-convex pattern Formability and strength are deteriorated.

The present invention has been made in view of the above circumstances, and therefore an object thereof is to provide an inorganic molded plate which can easily form a thick laminated inorganic mat and can improve both the uneven pattern formability and the strength. It is to provide a manufacturing method.

[0006]

In order to achieve the above object, according to the method for producing an inorganic molded plate of claim 1 of the present invention, the main raw materials are mixed in a dry state or in a state of water content of 60% or less. The backing layer is formed by spraying the forming raw material on the forming conveyor, the slurry prepared by mixing the main raw material with water is formed into a sheet by the sheet making device to form an inorganic sheet material, and the inorganic sheet material is crushed. While being roughly crushed by a dispersing means, dispersed and laminated on the upper surface of the back surface layer to form an intermediate layer, and on the upper surface of the intermediate layer, the main raw material is in a dried state or a water content of 60% or less, like the back surface layer. The molding raw material mixed in the above is sprayed to form a surface layer to form a laminated inorganic mat having a three-layer structure, and the laminated inorganic mat is press-molded and cured and cured.

According to this manufacturing method, both the back surface layer and the surface layer are formed in a dry state or a forming raw material having a water content of 60% or less. Therefore, it is possible to easily form the back surface layer and the front surface layer having a required thickness without causing the problems of the dehydration of the slurry and the problem of the outflow of the slurry as in the back surface layer and the front surface layer. Further, for the intermediate layer, the inorganic sheet-shaped material produced by paper-making the slurry with a paper-making apparatus is roughly crushed to form an intermediate layer by dispersing and laminating on the upper surface of the back surface layer, thus forming the intermediate layer by paper-making of the slurry. The raw materials are sufficiently mixed to form a uniform intermediate layer with little density variation, and the intermediate layer does not require dehydration treatment or wetting treatment, so that the intermediate layer having a required thickness can be easily formed.

Further, as in claim 2, the fibers to be mixed with the forming raw material for forming the back surface layer and the surface layer have a length of 5 m.
It is preferable to use long fibers of m to 30 mm (conventional general fiber length is 2.5 mm or less). Thus, by using long fibers, the reinforcing effect of the fibers can be enhanced.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. First, based on FIG. 1, a papermaking apparatus 1
The configuration of 0 will be described. The endless filter belt 11 is composed of a belt-shaped filter cloth or a water-permeable felt, and the drive roller 1
2. It is wound around a large-diameter cylindrical rotating body 14 via a plurality of tension rollers 13 and 22. Filtration belt 11
Runs substantially horizontally from the upper end of the peripheral surface of the cylindrical rotating body 14 toward the drive roller 12, and conveys the inorganic sheet-like material formed by the filtration belt 11 in the horizontal direction. Further, a whipper roll 15 and a filter belt cleaning device 16 are provided in the traveling path of the filter belt 11 from the drive roller 12 to the cylindrical rotating body 14. The whipper roll 15 is composed of a rotating body having a water sprinkling function, and scrapes the residue on the surface of the filtration belt 11 while sprinkling the filtration belt 11 to prevent clogging of the filtration belt 11.

On the other hand, the cylindrical rotating body 14 is formed into a porous or mesh shape, and the lower half thereof is immersed in the slurry 18 of the forming raw material stored in the storage tank 17. A plurality of agitators 19 for agitating and homogenizing the slurry 18 are provided at the bottom of the storage tank 17.

The inside of the cylindrical rotary member 14 is divided into four regions at 90 ° pitch, and the regions are submerged below the liquid surface of the slurry 18 to form adsorption regions. The filtration belt 11 that is stretched around the cylindrical rotating body 14 is tensioned by a tension roller 22 so as to come into close contact with the suction area. On the other hand, the area is located at a height higher than the liquid surface of the slurry 41, the area is the dehydration area, and the area is the non-decompression area. These 4
The three regions 1 to 3 do not rotate even if the cylindrical rotating body 14 rotates, and are fixed at fixed positions.

The rotary valve 20 provided at the center of the cylindrical rotating body 14 is provided with a large number of suction pipes (not shown) radially for applying a suction force to the outer peripheral surface of the cylindrical rotating body 14. Has been. This cylindrical rotating body 14
The suction area is connected to a vacuum pump (not shown) or the like through the rotary valve 20, and the vacuum suction force of the suction area allows suction of the thick inorganic sheet material on the filtration belt 11. The dehydration region is connected to the suction port of a high-pressure blower (not shown) via the rotary valve 20 so that decompression dehydration can be performed with a large suction air volume. On the other hand, the non-decompressed area is not decompressed, so
In this non-depressurized area, the filtration belt 11 does not have to be adsorbed by the cylindrical rotating body 14, and the filtering belt 11 can be smoothly pulled out straight from the upper end of the circumferential surface of the cylindrical rotating body 14 in the conveying direction. There is.

Further, a dehydration box 21 is provided on the lower surface side of the filtration belt 11 which conveys the inorganic sheet-like material adsorbed and dehydrated by the cylindrical rotating body 14, and the dehydration box 21 is provided with a Nash pump (not shown). ) Or the like, the inorganic sheet material on the filtration belt 11 is dehydrated under reduced pressure.

Using the space from the lower side to the front side of the papermaking apparatus 10 constructed as described above, the molding conveyor 23 is installed so as to be inclined upward. This molding conveyor 23 is also the same as the filtration belt 11 of the papermaking apparatus 10,
It is composed of a belt-shaped filter cloth or a water-permeable felt, and is stretched between the driving roller 24 and the driven roller 25.
A hopper 26 for accommodating the molding material for the back surface layer having the composition shown in Table 1 described below is installed on the lower side of the molding conveyor 23, and the molding material for the back surface layer is formed at the discharge port of the hopper 26. A molding material discharge roll 27 is provided on 23 to form the back surface layer A by distributed supply. The forming raw material for the back surface layer is fed into the hopper 26 from the forming raw material supply device 28 by the conveyor 29.

Further, a water spray nozzle 35 is installed below the paper making apparatus 10, and the raw material for forming the back surface layer A on the molding conveyor 23 is moistened by the water spray from the water spray nozzle 35. A pair of crushing / dispersing rotators 30 (coarse crushing / dispersing means) is provided below the front end of the filtering belt 11 of the papermaking apparatus 10 in the conveying direction. In the process of passing between the crushing / dispersing rotators 30 and dropping onto the molding conveyor 23, the inorganic sheet material is roughly crushed by both crushing / dispersing rotators 30, and the back surface layer A of the molding conveyor 23 is crushed. An intermediate layer B is formed by being dispersed and laminated on the upper surface.

In this case, in order to surely drop the inorganic sheet-like material from the front end of the filtration belt 11 in the transport direction, the drive roller 12 located inside the front end of the filtration belt 11 in the transport direction is made porous or mesh-shaped. It is formed and air is blown into it from a blower (not shown) or the like, so that the inorganic sheet material is forcibly dropped by air blow from the front end portion of the filtration belt 11 in the conveyance direction.

On the other hand, on the upper side of the molding conveyor 23, a hopper 31 for accommodating the molding material for the surface layer having the composition shown in Table 1 described later is installed, and the discharge port of the hopper 31 is used for molding the surface layer. Forming material discharge rolls 32 are provided to disperse and supply the material to the upper surface of the intermediate layer B on the molding conveyor 23 to form the surface layer C. A forming raw material for the surface layer is sent from the forming raw material supply device 33 into the hopper 31 by a conveyor 34. Further, a water spray nozzle 36 is installed in front of the hopper 31 in the conveying direction, and the surface layer C on the molding conveyor 23 is sprayed by the water spray nozzle 36.
The forming raw material is moistened. Instead of the water spray nozzle 36, a slurry spraying device for spraying the slurry of the forming raw material may be installed.

A roll press 37 is installed in front of the water spray nozzle 36 in the conveying direction. This roll press 37
Is rotated at the same speed as the molding conveyor 23, and a laminate of three layers of molding raw material is compression-molded by a roll press 37 to form a laminated inorganic mat 38 having a three-layer structure. A dewatering box 39 is provided below the roll press 37 with the molding conveyor 23 interposed therebetween. The dewatering box 39 is evacuated by a Nash pump (not shown) or the like to perform compression molding by the roll press 37. The inorganic mat 38 is dehydrated under reduced pressure. A flat plate press may be used instead of the roll press 37.

Using the molding apparatus configured as described above, 3
A method of molding the layered laminated inorganic mat 38 will be described. The composition of the forming raw material for each layer is shown in Table 1 below.

[0020]

[Table 1]

The long fibers to be added to the raw materials for forming the back surface layer A and the front surface layer C are vinylon fibers, polypropylene fibers, acrylic fibers, and other synthetic fiber bunching materials having a length of 5 mm to 30 mm, and
Chopped strands having a length of 10 mm to 25 mm of alkali resistant glass fibers may be used. The longer the length of the long fibers, the stronger the reinforcing effect becomes, but on the other hand, the longer the fibers become, the more easily the long fibers are entangled with each other and it becomes difficult to uniformly disperse them. The fiber length of is suitable. These long fibers are not mixed with the forming raw material of the mid layer B. This is because in the slurry of the forming raw material, the long fibers are entangled with each other and tend to be aggregated, which causes a problem in dispersibility.

The forming raw materials for the back surface layer A and the front surface layer C are mixed in a dry state or in a state of having a water content of 60% or less, and housed in the forming raw material supply devices 28 and 33. Then, the forming raw materials in the forming raw material supply devices 28 and 33 are transferred to the conveyor 2.
It is thrown into the hoppers 26, 31 by 9, 34. Forming material discharge roll 2 from the discharge port of the hopper 26 for the back surface layer
The forming raw material for the back surface layer is uniformly dispersed and supplied onto the molding conveyer 23 by 7 to form the back surface layer A. The back surface layer A is, while being conveyed by the molding conveyor 23,
It is moistened by the water spray from the water spray nozzle 35.

On the other hand, the forming raw material for forming the intermediate layer B is mixed with water to prepare a slurry 18, and the slurry 18 is stored in a storage tank 17 of the papermaking apparatus 10 to form the endless filtration belt 1.
1 is immersed in the slurry 18 in the storage tank 17 to rotate the cylindrical rotating body 14 and the pressure inside the cylindrical rotating body 14 is reduced, so that the filtration belt 1 is suspended in the slurry 18.
The molding raw material is conveyed while being continuously adsorbed on the surface of 1.
As a result, the inorganic sheet-like material adsorbed on the filtration belt 11 is continuously conveyed to the front end portion of the filtration belt 11 in the conveyance direction.

Then, the inorganic sheet-like material is dropped from the front end portion of the filtration belt 11 in the conveying direction by air blow, and in the middle thereof, it is roughly crushed by the crushing / dispersing rotator 30 and the back surface layer A of the molding conveyor 23 is crushed. The intermediate layer B having a uniform thickness is formed by being uniformly dispersed and laminated on the upper surface.

The molding material for the surface layer is uniformly dispersed and supplied from the discharge port of the hopper 31 for the surface layer to the upper surface of the intermediate layer B by the molding material discharge roll 32 to form the surface layer C. The surface layer C is moistened by water sprinkling from the water sprinkling nozzle 36 while being conveyed by the molding conveyor 23.

The laminate of the forming raw materials thus laminated in three layers is compression-molded by the roll press 37,
A laminated inorganic mat 38 having a layered structure is formed. The laminated inorganic mat 38 is conveyed to the next step of providing a concavo-convex pattern imparting step, the laminated inorganic mat 38 is press-molded by a template (not shown) of a flat plate press, and as shown in FIG. The inorganic molded plate 38 'having a pattern is molded. After that, the inorganic molded plate 38 'is conveyed to a heat curing curing step, and is heat-cured for 8 hours in an atmosphere of a temperature of 80 ° C. and a humidity of 90 to 95%, and then moisture evaporation from the surface of the inorganic molded plate 38' is performed. Wrapping to prevent the 70 ℃
Will be cured for 15 hours in the atmosphere. Thereafter, the inorganic molded plate 38 'is commercialized through a cosmetic finishing process such as painting.

Incidentally, the curing method is not limited to the above-mentioned method, and a usual autoclave may be used.

The present inventor measured the physical properties of the inorganic molded plate 38 'of the example manufactured as described above, and obtained the measurement results shown in Table 2 below.

[0029]

[Table 2]

In Table 2, in Comparative Example 1, an inorganic sheet-like material is formed by making a slurry having the composition shown in Table 3 below by a flow-on paper making machine (a paper making machine of a type in which the slurry is supplied onto a filtration belt). Then, 8 layers of this inorganic sheet material was wound around a making roll, and an inorganic mat obtained by cutting and expanding this was press-formed with a flat plate template,
It is an inorganic molded plate produced by carrying out the same curing and curing as in the example.

[0031]

[Table 3]

Further, in Comparative Example 2, the slurry having the composition shown in Table 3 above was made into a sheet by a flow-on sheet making machine to form an inorganic sheet material, and the inorganic sheet material was applied to a making roll.
Layer-wrapped, peeled and crushed, dispersed and laminated on a molding conveyor, compression-molded with a roll press, and press-molded with this inorganic mat using a flat plate template, followed by curing and curing in the same manner as in the example. It is an inorganic molded plate produced by.

Comparing the physical properties of these Comparative Examples 1 and 2 with those of the Examples, as shown in Table 2 above, all of the physical properties of the Examples are superior to those of the multilayer stacking method using the making roll of Comparative Example 1, and the inorganic materials are It has been found that it is possible to form a deep relief pattern on the surface of the molded plate. Further, it was found that the flexural strength of the example was significantly improved as compared with the comparative example 2.

In the above embodiment, the filtration type papermaking apparatus 10 was used, but instead of this, a flow-on papermaking machine or a Haschek type papermaking machine may be used, or an inclined type fourdrinier type machine may be used. An inorganic sheet material may be formed using a papermaking machine.

The composition of the forming raw material used in the forming method of the laminated inorganic mat 38 of the present invention is not limited to the above Table 1, and the forming method of the present invention can be applied to the forming raw material of various compositions in which cement and fibers are mixed. Is applicable.

In the above embodiment, the filtration belt 11 is used.
In order to reliably drop the inorganic sheet-like material from the front end in the transport direction of the, the air blow system was adopted.
Install a scraping roll near the front end of 1
The forming raw material may be scraped off from the front end portion of the filtration belt 11 in the conveying direction by the rotation of the scraping roll.

[0037]

As is apparent from the above description, according to the method for producing an inorganic molded plate of the present invention, the back surface layer and the surface layer are formed in a dry state or a molding raw material having a water content of 60% or less,
Since the intermediate layer is formed by crushing the inorganic sheet-like material produced by the paper making apparatus, the back surface layer and the surface having the necessary thickness can be formed without the conventional problems of slurry dehydration and slurry outflow. A layer can be easily formed, and a uniform intermediate layer with little density variation can be formed thickly, a laminated inorganic mat having a thick three-layer structure can be easily formed, and both the uneven pattern formability and strength can be improved. .

Further, in claim 2, as the fibers to be mixed with the forming raw material for forming the back surface layer and the front surface layer, the length is 5 m.
Since the long fibers of m to 30 mm are used, the reinforcing effect by the long fibers can be enhanced while ensuring the dispersibility of the long fibers, and the strength can be further improved.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of an apparatus for manufacturing an inorganic molded plate used in an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a part of an inorganic molded plate.

[Explanation of Codes] 10 ... Papermaking device, 11 ... Filtration belt, 12 ... Driving roller, 14 ... Cylindrical rotating body, 17 ... Storage tank, 18 ... Slurry of forming raw material, 19 ... Stirrer, 21 ... Dehydration box, 2
3 ... Molding conveyor, 26 ... Back surface layer hopper, 30 ... Coarse crushing rotating body (coarse particle dispersing means), 31 ... Surface layer hopper, 35, 36 ... Sprinkling nozzle, 37 ... Roll press,
38 ... Laminated inorganic mat, 38 '... Inorganic molded plate, 39
... dehydration box, A ... back surface layer, B ... middle layer, C ... front surface layer.

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) B28B 3/12 B28B 5/02 B28B 1/16 B28B 1/30

Claims (2)

(57) [Claims] 1. A method for producing an inorganic molded plate containing cement and fibers as main raw materials, which comprises mixing the main raw materials in a dry state or a water content of 60% or less and spraying the raw materials on a forming conveyor. To form a backside layer, form a slurry prepared by mixing the main raw material with water in a paper making device to form an inorganic sheet-like material, and coarsely crush the inorganic sheet-like material with a crushing / dispersing means. An intermediate layer is formed by dispersing and laminating on the upper surface of the back surface layer, and a molding raw material obtained by mixing the main raw material in a dry state or a water content of 60% or less is sprinkled on the upper surface of the intermediate layer, like the back surface layer. And forming a surface layer to form a laminated inorganic mat having a three-layer structure, press-molding the laminated inorganic mat, and curing and curing the laminated inorganic mat. 2. The method for producing an inorganic molded plate according to claim 1, wherein the fibers mixed in the forming raw material for forming the back surface layer and the surface layer are long fibers having a length of 5 mm to 30 mm. .