JPS5839042B2 - Manufacturing method of glass fiber reinforced cement sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a glass fiber reinforced cement sheet.

Conventional methods for producing glass fiber reinforced cement include a premix method, a direct spray method, and a spray dehydration method.

The premix method has the disadvantage that the glass fibers are loosened and the strength of the resulting cement sheet is reduced because the glass fibers and cement are mixed in a blender.

The direct spray method has disadvantages in that the productivity is low and the strength of the obtained cement sheets is poor because the cement sheets are prepared one by one in a mold using a mortar spray gun equipped with a roving cutter.

In the spray dewatering method, cement slurry and chopped glass fiber strands are simultaneously sprayed onto a sheet production table and dehydrated to produce a cement sheet, so that cement sheets can be produced continuously.

However, this method had the problem that the strength was somewhat inferior because the cement slurry did not penetrate into the overlapped portion of the glass fibers, and it was difficult for the cement slurry to penetrate into the single fibers of the chopped glass fiber strands.

Therefore, an object of the present invention is to provide a method for manufacturing a glass fiber reinforced cement sheet with high strength and good productivity.

In summary, the method of the present invention involves impregnating a long glass fiber bundle with water, adhering cement powder to the long glass fibers, allowing the cement powder to enter the inside of the long glass fibers, and cutting the resulting cement slurry sheet. This is characterized by the fact that it is sprayed on top and then made into a board.

It is preferable to use alkali-resistant glass fibers as the long glass fibers, and it is preferable to cut them into pieces of about 13 to 38 mm.

Also, the amount used is 1 of the cement that makes up the cement slurry.
2 to 7 Ll per 00 parts (based on weight, the same applies hereinafter):
It is preferable to use

As the cement powder, cements such as Portland cement and blast furnace cement are used.

If necessary, a filler may be mixed therein.

Examples of the filler include fine powder silica, amorphous silica, silica, aluminum hydroxide, activated alumina, and zeolite, which may be used alone or in combination.

The amount of filler used is 5 to 100 parts of cement powder.
It is desirable that the amount be 30 parts, preferably 10 to 20 parts.

The water with which the long glass fibers are impregnated may be ordinary water, but the effect will be even higher if a water reducing agent is added.

Its usage is free.

In this way, since the cement powder is attached after the long glass fibers are impregnated with water, the cement powder penetrates through the internal residue of the long glass fibers, leaving no part where the cement can penetrate.

Therefore, the strength of the sheet increases.

In addition, continuous production is possible because glass fibers coated with cement are spread onto a cement slurry sheet.

Next, the method of the present invention will be explained in detail with reference to the drawings.

That is, the glass long fiber bundle 1 is guided into the water tank 2,
It can be impregnated with water 2a.

Next, this is introduced into the cement tank 3, and the cement powder 3a is attached to the long glass fiber bundle 1.

This is guided to a roving roll 4 and pressurized to cause the cement powder 3a to enter the inside of the long glass fiber bundle 1.

Next, this is cut with a roving cutter 5, and then spread on top of the cement slurry 8 which has been spread in a sheet form on a felt conveyor 6 with a sprayer a.

Then, spray b75-*te et al. cement slurry is further sprayed, and this is pressure-formed with a Karo pressure forming roll 9, and cut into a predetermined size with a cutter 10.

Note that 11 is a vacuum dehydration box. In this case, when the long glass fiber bundle 1 is impregnated with water 2a, the long glass fiber bundle 1 becomes easier to bundle, but after that, the cement powder 3
Since the glass fiber bundle 1 is attached, the convergence of the long glass fiber bundle 1 is prevented.

Therefore, the glass fibers are uniformly dispersed on the cement slurry 8 during scattering after cutting.

The glass fiber reinforced cement sheet thus obtained is cured.

For curing, 11 commonly used curing methods are used, such as heating curing, underwater curing, and natural curing.

Next, examples will be described.

Examples 1 to 3 1 A cement slurry is prepared by mixing Portland cement, a water reducing agent, silica stone, and water in the proportions shown in the table below, and this is spread onto the felt conveyor 6 using the device shown in the drawing, and alkali-resistant fibers are applied to the slurry. A glass fiber-reinforced cement sheet was manufactured by spraying the following materials in the proportions shown in the table below.

Note that the cutting dimension of the glass fiber is 25 mm.

Comparative Examples 1 to 2 - A cement slurry is made by blending Portland cement, silica stone, and water in the proportions shown in the table below, and this and alkali-resistant glass fiber are sprayed onto a sheet making table using a spray dehydration method to make glass fiber reinforced cement. The sheet was manufactured.

Note that the glass fiber cutting dimension is 25 mm.

The bending strength of the glass fiber reinforced cement sheets obtained in the above Examples and Comparative Examples at 28 days old (underwater curing) was
Shown in the table.

As shown in Table 3, the glass fiber reinforced cement sheet manufactured by the method of the present invention is 10% to 20% higher than that of the conventional example.
An increase in strength was observed.

[Brief explanation of drawings]

The drawing is a configuration diagram of a manufacturing apparatus for implementing the method of the present invention. DESCRIPTION OF SYMBOLS 1... Glass long fiber bundle, 2a... Water, 3a... Cement powder, 4... Roving roll, 5... Roving cutter, 6... Felt conveyor, 8... Cement slurry.

Claims (1)

[Claims] 1. After impregnating a long glass fiber bundle with water, cement powder is attached to the long glass fiber bundle so that the cement powder penetrates into the inside of the long glass fiber bundle, and after cutting it, it is placed on a cement slurry sheet. A method for manufacturing a glass fiber reinforced cement sheet, which comprises spreading and forming the sheet. 2. For the manufacturing method described in claim 1, a long glass fiber bundle is impregnated with water, and then cement powder is attached to the long glass fiber bundle, and the cement powder is then applied to the inside of the long glass fiber bundle by applying pressure. A method for producing a glass fiber reinforced cement sheet characterized by rapid penetration.