JPH01282170A - Production of inorganic sheet - Google Patents

Abstract

PURPOSE:To reduce the number of receiving sheets and to improve the appearance of a product by covering a green sheet laminated through a releasable sheet with a heat insulating material when a green sheet obtained by extruding a composition contg. a hydraulic inorg. material and water is placed on the receiving sheet and then cured. CONSTITUTION:An inorg. sheet composition obtained by mixing a hydraulic inorg. material and water is extruded by an extruder 1 into a green sheet 20. The sheet 20 is placed on a receiving machine 2 and drawn out, and a releasable sheet 21 from a sheet supply machine 3 is supplied onto the surface of the green sheet 20. The green sheet 20 and the sheet 21 are cut by a cutter 4 to a specified length, and placed on the receiving sheet 22 over which a heat insulating sheet has previously been laid. Other green sheet 20 and sheet 21 are laminated on the sheet 21 on the receiving sheet 20. A specified number of green sheets 20 are laminated through the sheet 21, the receiving sheet 22 is taken out, the entire periphery of the laminate 24 is covered with a releasable sheet 25 and a heat insulating material 26, and curing is carried out under such conditions.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to the reaction heat of a green board formed by extrusion molding an inorganic board composition containing a hydraulic inorganic material and water, and the reaction heat of this green board. This invention relates to a method for producing an inorganic board that undergoes self-promoting curing using the moisture contained therein.

(Prior art) Generally, when manufacturing an inorganic board, an inorganic board composition containing a hydraulic inorganic material such as cement and water is
A raw board is formed by extrusion from an extruder, and the raw board is placed on a receiving plate while being taken up by a take-up machine, and
The main method used has been to cure this material in an autoclave or steam after it has been allowed to stand for a predetermined period of time.

(Problems to be Solved by the Invention) According to the above method, an inorganic board with relatively high strength can be obtained and the curing period can be shortened, compared to the case where raw boards are left indoors to cure. There is an advantage. However, in this conventional method, a receiving plate is required for each extruded green board, and therefore, a considerable number of receiving plates are required during mass production.

In addition, regarding the method of curing raw boards, in the case of steam curing as mentioned above, efflorescence tends to occur on the surface of the inorganic board that is the obtained product, and it is difficult to obtain a smooth surface. However, there are drawbacks that impair the appearance of the product itself. Furthermore, when curing raw boards in an autoclave, this method not only requires equipment costs, but also has the disadvantage of being inferior in productivity because it is a batch method.

The present invention solves the above-mentioned drawbacks, and its purpose is to:
To provide a method for manufacturing an inorganic board that can obtain an inorganic board with a smooth surface and good appearance without causing efflorescence.

Another object of the present invention is to provide an inorganic material that does not require expensive equipment, has the same strength as autoclave or steam curing, can save on receiving plates, and can improve productivity. The object of the present invention is to provide a method for manufacturing a board.

(Means for Solving the Problems) A method for manufacturing an inorganic board developed from scratch involves extruding a raw board formed by extruding an inorganic board composition containing a hydraulic inorganic material and water, and placing each raw board on a receiving plate. The method includes a step of laminating a plurality of sheets with a release sheet interposed therebetween, and a step of curing the laminate while being covered with a heat insulating material, thereby achieving the above object.

(Example) The present invention will be explained in detail below.

FIG. 1 schematically shows an apparatus for manufacturing an inorganic plate used in the present invention.

This inorganic board manufacturing apparatus includes an extruder 1 that extrudes an inorganic board composition into a plate shape, a take-off machine 2 that is continuously driven and arranged in the extrusion direction of the extruder 1, and a take-off machine 2 located above the take-off machine 2. A raw board 2 that is arranged and extruded from an extruder 1
a release sheet supplying machine 3 that covers the upper surface of the sheet 0 with a release sheet 21; a cutter 4 that cuts the raw board 20 and the release sheet 21 to a predetermined length on a take-up machine 2; an extruder 1 and a take-off machine. 2
A conveying device 5 is provided with a large number of feed rollers 58 that are disposed at a lower position and continuously move the receiving plate 22 in the direction of arrow A in the figure. a belt conveyor 6 that can move a receiving plate 22;
An elevator-type lowering device 7 that lowers the belt conveyor 6, and a lower part that transports the receiving plate 22 in the opposite direction (direction of arrow B) to the transport device 5, which is disposed below the transport device 5. Conveying device 8 and this downward conveying device 8
A belt conveyor 9 is disposed at the end of the conveyance side and on which the receiving plate 22 can be placed, and an elevator-type lifting device 10 that raises the belt conveyor 9 to the conveyance start end of the upper conveyance device 5. It is configured with the following.

The feeding directions of the belt conveyors 6 and 9, which are disposed in the descending device 7 and the ascending device 10 so as to be able to rise and fall freely, are configured to be reversible, and the belt conveyor 6, which is disposed in the descending device 7, is a conveying device in the ascending position. 5, and in its lowered position, it is driven in the same direction as the downward conveyance device. Further, the belt conveyor 9 disposed in the lifting device 10 is configured to be driven in the same direction as the lower conveyance device 8 in its lowered position, and driven in the same direction as the conveyance device 5 in its raised position. A contact plate 11 is provided at the upper end of the lowering device 7 on the conveyance end side, and when the conveyance side end of the receiving plate 22 sent by the conveyance device 5 and the belt conveyor 6 comes into contact with this contact plate 1. , the driving of the belt conveyor 6 is stopped, and the belt conveyor 6 is lowered by a lowering device 7. When the belt conveyor 6 is at the same height as the lower conveyor 8, the belt conveyor 6 is driven laterally in the opposite direction to the above to send the receiving plate 22 to the conveyor 8 side, and then the lower conveyor 6
The belt conveyor 6 is raised to standby in its original state. Further, a patch plate 12 is similarly provided at the lower transport side end of the lifting device 1o, and this patch plate 12
When it is detected that the receiving plate 22 has come into contact with the belt conveyor 9, the belt conveyor 9 is raised by the lifting device 1o while the driving of the belt conveyor 9 is stopped.

At the upper end of the lifting device 10, a sensor (
(not shown), and is configured such that the upper end height of the green plate 20 is automatically set to a predetermined position by a signal from this sensor, and the height of the conveying device 5 and the height of the heald conveyor The rising position of 6 is also on this belt conveyor 9.
They are linked so that they are aligned with the elevated position of the

Next, a method for manufacturing an inorganic board using the above manufacturing apparatus will be explained.

The inorganic board composition is prepared by mixing water with a hydraulic inorganic material such as cement or gypsum, and adding and mixing additives such as aggregate, reinforcing fibers, and viscosity modifiers as necessary. This inorganic plate composition is extruded from the extruder 1 into a plate shape to form a green plate 20.
is formed. The green plate 20 is pulled out while being placed on the take-up machine 2, and a release sheet 21 is supplied onto the surface of the green plate 20 from the sheet feeder 3. Release sheet 2
As the material 1, for example, an air-impermeable sheet such as polyester or polyethylene film, a porous sheet such as nonwoven fabric or felt, or a film-like material can be used.

Next, the green plate 20 and the release sheet 21 are cut into a predetermined length by the cutter 4 and sent to the conveying device 5 side. Since receiving plates 22 are placed on this conveying device 5 at appropriate intervals, the green plate 20 and the release sheet 21 are placed on this receiving plate 22.

Note that a heat insulating sheet 23 is placed on the upper surface of this receiving plate 22 in advance. When the receiving plate 22 carrying the raw board 20 and the release sheet 21 is conveyed to the patch plate 11 by the conveying device 5 and the belt conveyor 6, the lowering device 7 is driven and the receiving plate 22 is lowered together with the belt conveyor 6. Next, by driving the belt conveyor 6 and driving the downward conveying device 8, the receiving plate 22 is sent onto the belt conveyor 9 disposed in the lifting device 10, and then, by driving the lifting device 10 upward, the green plate 20 and the separation plate 22 are transported. The receiving plate 22 on which the mold sheet 21 is placed is conveyed together with the belt conveyor 9 to the conveyance start end of the conveyance device 5. Then, as shown in FIG. 2, another green board 20 and a release sheet 21 are laminated on top of the green board 20 and release sheet 21 again.

Note that when a plurality of raw plates 20 and release sheets 21 are stacked on the receiving plate 22, the height of the uppermost release sheet 21 gradually increases, but this height is read by the sensor and the belt By changing the heights of the conveyor 9 and the conveying device 5, the raw board 20 sent from the take-up machine 2 can be supplied onto the receiving plate 22 on the conveying device 8 without any problem.

After the above steps are repeated and a predetermined number of raw plates 20 are laminated with the release sheet 21 interposed therebetween, this receiving plate 22
is taken out from this apparatus, and as shown in FIG. 3, the entire periphery of the laminate 24 stacked on the receiving plate 22 is covered with a release sheet 25 and a heat insulating material 26.

Then, the laminate 24 is cured in this state. Note that the heat insulating material 26 can be a sheet-like or plate-like material that has excellent heat insulating properties and does not allow moisture to pass through, and preferably covers the periphery of the laminate 24 without any gaps.

Thus, a plurality of raw boards 20 made of a hydraulic inorganic material are laminated on a receiving plate 22 with a release sheet 21 interposed therebetween, and this laminate 24 is covered with a heat insulating material 26. By curing the laminate 24, each raw board 20
This prevents moisture from evaporating from the laminate, allowing the hydration reaction to occur in the presence of sufficient moisture, and the heat generated by this hydration reaction brings the entire laminate 24 into a thermally cured state. The inorganic board thus obtained is used, for example, as a construction board.

(Example) The present invention will be specifically described below based on Examples.

Example 1" [- A cement mixture was prepared by blending in the proportions shown in Table 1, and a cement board was created using the manufacturing apparatus shown in FIG. 1. In addition, the extrusion opening dimensions of the mold of the extruder are 15 mm in the upper and lower dimensions and 300 mm in width, so the thickness is 15 mm and the width is 300 mm.
M green cement board was extruded. This semen,
20 raw boards were laminated with a polyethylene film interposed therebetween as a release sheet, and this laminate was covered and sealed with a release sheet and a heat insulating material as shown in Figure 3, and the laminate was cured in this state. I let it happen. After the laminate was sufficiently cured, each green cement board was separated to obtain a cement board.

A cement board was obtained in the same manner as in Example 1, except that a nonwoven fabric was used as the main release sheet.

A green cement board was formed using the same cement mixture as in Example 1, and 20 of the green cement boards were laminated on a receiving plate without using a release sheet, and this laminate was steam-cured (40
℃ and 95% humidity) to obtain a cement board.

A green cement board was formed using the same cement mixture as in Example 1, and 20 sheets of this green cement board were laminated on a receiving plate without using a release sheet, and this laminate was left indoors. A cement board was obtained by curing.

Next, the cement boards obtained in Example 1.2 and Comparative Example 1.2 were left indoors for 64 hours, and then the bending strength of each cement board (the number of specimens was 6) was measured.
The appearance of each cement board was visually observed.

The results are summarized in Table 1.

(The following is a blank space) From the results in Table 1, it can be seen that when a cement board was prepared by steam curing as in Comparative Example 1, efflorescence occurred and the surface smoothness was poor.

Furthermore, when the green cement board was cured indoors as in Comparative Example 2, it was found that the bending strength was insufficient. On the other hand, as in Examples 1 and 2, the cement boards obtained by the method of the present invention have sufficient bending strength, are free from efflorescence, and have excellent surface smoothness. was confirmed.

In addition, changes in surface temperature during curing of the green cement boards of Example 1 and Comparative Example 1 were measured, and the results are shown in FIG.

This result shows that in Example 1, due to the hydration reaction of the hydraulic inorganic material, almost the same level of heat generation as in steam curing occurs at the initial stage of curing.

(Effects of the Invention) As described above, according to the present invention, an inorganic board having a strength comparable to that of an inorganic board obtained by conventional autoclave curing or steam curing and a good appearance can be obtained. Therefore, there is no need for autoclave curing equipment, etc., which reduces equipment costs, and allows continuous production to improve productivity. Further, even when producing inorganic plates in large quantities, the number of required receiving plates is small, making it economical.

Fig. 1 is a schematic diagram of an inorganic plate manufacturing apparatus according to an embodiment of the present invention, and Fig. 2 is a schematic diagram of an apparatus for manufacturing an inorganic board according to an embodiment of the present invention, and Fig. 2 shows a lamination of a green plate and a release sheet on a receiving plate using the apparatus. FIG. 3 is a cross-sectional view showing the curing state of the laminate, and FIG. 4 is a graph showing changes in temperature of green cement boards of Example 1 and Comparative Example 1.

20... Raw board, 21... Release sheet, 22... Receiving plate, 26... Heat insulating material.

that's all

Claims (1)

[Claims] 1. A process of laminating a plurality of raw boards formed by extrusion molding an inorganic board composition containing a hydraulic inorganic material and water on a receiving plate with a release sheet interposed between each, and insulating the laminate. A method for manufacturing an inorganic board, comprising the step of curing the board while covered with wood.