JPS6029602B2 - Manufacturing method of glass fiber reinforced cement board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides fiber slurry 1 containing glass fibers containing no cement, and a cement slurry containing no glass fibers.
The method for manufacturing a glass fiber reinforced cement board is characterized by paper-forming and laminating 2 and 2 sequentially in time, and its purpose is to obtain a reinforced cement board with a good yield using glass fiber as a reinforcing material. The purpose of the present invention is to provide a method for manufacturing a glass fiber reinforced cement board.

Recently, in the production of asbestos cement boards, research has been conducted on glass fiber reinforced cement boards (CRC boards) that use glass fiber as a reinforcing material as an alternative fiber to asbestos due to the problem of asbestos pollution and the difficulty in obtaining keys due to resource depletion. , which is currently under active development and has a promising future, is usually produced using the following methods.

(1) Direct spray method Spray dehydration method (0) Method method (m) Extrusion method (N) Wet papermaking method Among these methods, method (1) is the most widely adopted; The drawback is that the production speed is slow and productivity is not high, making it unsuitable for mass production.

Method (0) is also suitable for on-site work, but has drawbacks such as poor productivity and difficulty in developing strength. (m)
This method also has low productivity, and there are few examples of it being put into practical use.
Method (W) is also called the Hatschek method, which has the highest productivity among these and is suitable for factory production, and has recently been studied and examined in various ways. The formulation has poor dispersibility and
There is a problem that papermaking is not possible. That is, in addition to GF, asbestos is simultaneously blended as fibers, and if necessary, fibers such as pulp are blended, and the mixture is mixed with cement to form paper. In this method, by blending asbestos and pulp, cement particles are adsorbed onto the surface of the asbestos and pulp to improve the yield of cement. It is necessary to contain at least about 1% by weight or more of asbestos alone or at least 4% by weight of asbestos pulp, and it is impossible to completely eliminate asbestos. In other words, as mentioned above, if the amount of asbestos is less than 4% by weight, the furnace overspeed will be slow and the yield of cement will be poor. The present invention aims to eliminate the drawbacks of such a conventional system, and will be described in detail below with reference to the accompanying drawings.

The most important feature of the present invention is that when manufacturing a glass fiber reinforced cement board using a wet papermaking device, glass fibers and cement are pumped up in separate slurry vats. The attached figure shows an example of a wet (Hacheck) papermaking apparatus, in which any number of vats 3a, .
A liquid containing glass fibers, water, and a surfactant if necessary, that is, fiber slurry 1, is poured into some of 3b..., and the rest is cement slurry 2, which is a mixture of cement, water, pulp, etc. throw into. In the illustrated example, the bat 3a
, 3b, 3c are used, and the fiber slurry 1 is charged into the first and third vats 3a, 3c, and the cement slurry 2 is charged into the second vat 3b.
At this time, the vat 3a into which the fiber slurry is charged,
The mesh of the lifting cylinders 4a and 4c of 3c may be 50 to 6o mesh, which is used in a normal hacheck machine, but the mesh of the second raising cylinder 4b of the bagnit 3b of cement slurry 2 is finer than this, and is 80 to 100 mesh. The range should be about the size of a mesh. In addition, the concentration of fiber slurry 1 (glass fiber content) is arbitrary, but the pulp content of cement slurry 2 is the total solid content of cement and fibers used.
The amount is 1 to 4 parts by weight relative to 0 parts by weight. Furthermore, the blending amount of glass fibers in the fiber slurry 1 is arbitrary as described above and is not limited, but is preferably about 0.1 to 5% by weight. In addition, the types of glass fiber are chopped strand,
Any wool-like fiber may be used, and the length of the fibers may be arbitrary; however, in the case of chopped strands, the preferred length is usually about 1/4 to 2 inches. Further, the composition of the glass may be any of alkali-resistant glass fibers, E-glass fibers, C-glass fibers, etc., but alkali-resistant glass fibers are most preferred as reinforcing materials for cement. Here, the content of pulp in the cement slurry 2 is set at 1 to 4% by weight because if it exceeds 4%, there will be a problem in the non-flammability of the final product, and if it is below 1%, the content of pulp in the cement slurry 2 will be 1 to 4% by weight. This is because the gait becomes extremely poor. In addition, the reason why the mesh of the drawing cylinder 4b for the cement slurry 2 is set to 80 to 100 mesh is because the mesh is finer than 100 mesh.
Cement yield improves, but reactor water resistance deteriorates and
This is because if the mesh size is 0 mesh or less, the yield of cement will be poor in cement slurry 2 with a pulp content of 1 to 4% by weight. In the case of the illustrated example, the fiber slurry 1 in the first vat 3a is first drawn up in the drawing cylinder 4a, passed through a furnace, and transferred onto the endless felt 5, and then transferred to the second vat 3a. The cement slurry 2 in the third vat 3b is drawn up in the drawing cylinder 4b, passed through a furnace, and transferred onto the wet mat made of glass fibers, and the fiber slurry 1 in the third vat 3c is The material is polished in the papermaking cylinder 4c, passed through a furnace, and transferred onto the second cement layer.

At the time of each of these Qin transfers, the coach roll 6a
, 6b, 6c, and after transfer, water is dehydrated in suction boxes 7a, 7b, 7c. From then on, the making roll 8 is made in the same way as in the normal Hatchek papermaking method.
It is wound up, cut when it reaches a predetermined thickness, and subjected to post-processing such as press molding and curing as necessary. 9 in the figure is the bottom roll. Incidentally, the order of making up the fiber slurry 1 and the cement slurry 2 and the number of making up can be arbitrarily set other than the above example. In the present invention, as mentioned above, the fiber slurry and the cement slurry are sanded and laminated at different times, so the concentrations of the two slurries, the mesh of the sanding cylinder, etc. are different from each other. It is possible to independently set the optimum value, and in particular, it is easy to set the conditions of the cement slurry to the optimum condition regardless of the fiber slurry, and there is no need to mix asbestos in the slurry as in the past. There is an advantage that a non-combustible reinforced cement board using glass fiber as a reinforcing material can be obtained continuously at the same pace as the cement. The present invention will be specifically described below based on examples.

〔Example〕

Using the Hacheck paper machine shown in the attached diagram, water containing 0.5% by weight of alkali-resistant glass fibers and 1% of a surfactant, that is, fiber slurry, was added to the first and third batts 3a and 3c. -1 was inserted.

On the other hand, in the second vat 3b, a cement slurry 2 having a weight ratio of ordinary Bortland cement and pulp of 1:2 and a slurry concentration of 10% mixed with water was charged. Further, the mesh of the papermaking cylinders 4a, 4c in the fiber slurry 1 of the vats 3a+3c was set to 60 mesh, and the mesh of the papermaking cylinder 4b in the cement slurry 2 of the vat 3b was set to 100 mesh. Then, the fiber slurry, cement slurry, and fiber slurry were laminated in this order at a papermaking speed of 5 k/min, wound on a making roll, and cut when the thickness reached the 6-side thickness.
A glass fiber reinforced cement board was obtained by curing in water for 1 day and naturally curing for 7 days.

[Brief explanation of the drawing]

The accompanying drawings are schematic illustrations of one embodiment of the invention.

Claims (1)

[Claims] 1. A method for manufacturing a glass fiber-reinforced cement board, which comprises forming and laminating a glass fiber-containing fiber slurry that does not contain cement and a cement slurry that does not contain glass fiber in sequence.