JPS6141508A - Manufacture of hydraulic inorganic board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing hydraulic inorganic boards used as building materials such as exterior materials.

[Background technology]

In the conventional semi-dry production method of hydraulic inorganic boards, cement,
When aggregates, cellulose fibers, organic synthetic fibers, etc. were matted and pressure-molded with a low amount of wet water, the fibers and cement powder tended to separate, resulting in non-uniform composition and poor strength development. Therefore, if a large amount of water is supplied at once, the fibers and cement powder tend to be granulated, so it is necessary to mix with a relatively low amount of wet water.

In addition, even if mixed with a low amount of wet water, additional watering is required to ensure good strength development of the hydraulic inorganic board, so the surface layer of the hydraulic inorganic board after watering may form a surface with low specific gravity. There was a drawback that the aggregate was exposed on the surface, degrading the surface appearance. For this reason, it has been difficult to form a thick hydraulic inorganic plate due to insufficient bending strength and poor adhesion of the surface coating film.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned background art, and its purpose is to supply a polymer flocculent to a fiber cement mixture, and then matte water supply test water hard inorganic plates on the front and back surfaces of the delicate cement mixture. The object of the present invention is to obtain a hydraulic inorganic board with a uniform specific gravity distribution by pressure molding without granulation to prevent separation of fibers and cement powder. Therefore, a thick hydraulic inorganic board with high bending strength and good surface coating performance is obtained.

[Disclosure of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below based on the drawings.

Cement is the main material, and lightweight aggregate such as pearlite Dopaμ
Fiber cement mixture 1 was prepared by mixing cellulose fibers such as fibers, organic synthetic fibers such as vinylon, polypropylene, etc. with a small amount of water, and this fiber cement mixture 1 was supplied to stirring row/L/3 of feeder 2. Later, this fiber cement mixture 1 is supplied to the conveyor 4, pressed with a preforming row μ5, and further pressed with a secondary molding row /L/6 to continuously form a hydraulic inorganic board 7. . At this time, the anionic polyacrylic acid is present in the fiber cement mixture 1 in an amount of 10 to 500 ppm based on the solid content of the hydraulic inorganic board 7.
A polymer flocculant such as amide may be supplied in liquid or powder form, and then water may be sprinkled on the front and back surfaces using water supply devices 8a and gb to improve the dispersibility of the water. In addition, 9 is a cutting cutter.

Examples 1.2 and comparative examples of the present invention are shown below.

[Example 1] 0 parts by weight of ordinary potato land, 7 parts by weight of pearlite as a lightweight aggregate, 7 parts by weight of pork loin [bum as fl.
5 parts by weight of polypropylene fibers, 2 parts of polypropylene fibers as organic synthetic fibers
When water is supplied to a fiber cement mixture prepared by kneading parts by weight and a small amount of water, 0.0% of anionic polyacrylamide aggregate is added.
A 171EI thick hydraulic inorganic plate was obtained by pressure molding a 171EI thick hydraulic inorganic plate by sprinkling water on 100 parts by weight of the solid content as a 05% aqueous solution. After molding, it was cured at room temperature at 60° CI and evaluated for performance after a week.

[Example 2] In the above-mentioned [Example 1], anionic polyacrylamide was added by simultaneous dry mixing and dispersion in a fiber cement mixture of aggregate, cellulose fiber, organic synthetic resin fiber, and ordinary Portland cement, and the plate thickness was 17 M. A hydraulic inorganic board was obtained. The molding conditions were the same as in [Example 1].

[Comparative example]

A hydraulic inorganic board having a thickness of 17 W was obtained under the same molding conditions as in [Example 1] without adding only the anionic polyacrylamide aggregate to the fiber cement mixture.

The appearance, specific gravity, frost damage resistance, and primary adhesion strength of the coating film of the surface layer of the hydraulic inorganic plates obtained in the above-mentioned [Example 1], [Example 2], and [Comparative Example] are shown in the table below.

Acrylic emulsion paint (solid content a%) on the product
After baking 15097Wl and painting it (80°CX3Q minutes), the planar adhesive strength was measured.

〔Effect of the invention〕

As mentioned above, the fiber cement mixture is supplied with a polymer agglomerate, and then water supply condensate hard inorganic plates are matted and pressure-formed on the front and back surfaces of the delicate cement mixture. Since the separation is agglomerated by this polymer aggregation material, a hydraulic inorganic plate with a uniform specific gravity distribution can be obtained without granulation. for that,
The surface layer is smooth and dense without exposing the lightweight aggregate, which has become brittle due to excess fibers, and has a beautiful surface appearance. In addition, the frost damage resistance and primary adhesion of the coating film (coating film performance) are good, and there is no peeling from the surface layer of the base material. In addition, the bending strength is slightly increased, and a thick hydraulic inorganic plate can be formed in a single layer.

[Brief explanation of the drawing]

FIG. 1 is a schematic process diagram showing a method for manufacturing a hydraulic inorganic board according to the pretext side of the present invention. 1... Delicate cement mixture, 2... Supply machine, 3 river stirring rolls, 4... Belt conveyor, 5... Preforming roll, 6... Secondary forming roll, 7... Hydraulic property Inorganic board, ga, 8b...water supply machine, 9...cutting cutter.

Claims (1)

[Claims] (1) Cement as the main material, lightweight aggregate and cellulose fiber,
In a method for producing hydraulic inorganic boards, in which a fiber cement mixture made by kneading organic synthetic fibers and a small amount of water is matted and pressure-formed using a semi-dry method, a polymer agglomerate is supplied to the fiber cement mixture, and then the fiber cement mixture is mixed with a small amount of water. A method for producing a hydraulic inorganic board, which comprises applying water to the front and back surfaces of a cement mixture, and then matting and press-forming the hydraulic inorganic board.