JPH054208A - Method for molding cement tile - Google Patents

Abstract

PURPOSE:To uniformize the strength of the whole of the recessed and protruding parts of a cement tile having deep unevenness formed thereto in a roll slipper molding method of the tile. CONSTITUTION:The supply hopper 3 of a cement compound 2 is provided on a pallet conveyor 1 becoming a product lower mold and the surface of the cement compound 1 supplied from said hopper 3 is pressed by a molding roller 4 to mold a cement tile 5 having a predetermained surface shape being a product. When compression molding is applied to the surface of the cement compound 2 on the pallet conveyor 1 by the molding roll 4, compression molding is carried out by a preparatory molding roll 5 forming protruding parts not reaching the objective protruding parts G1 on the surface of the product G and, thereafter, compression molding performed by the molding roll 4 forming the objective protruding parts. By compressing the cement compound by the molding rolls successively forming high protruding parts, the density of the protruding parts are enhanced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an inorganic plate, and more particularly to an improvement of a so-called roll slipper forming method for forming a product by supplying a cement compound material having a relatively low water content to a pallet conveyor.

[0002]

2. Description of the Related Art Conventionally, cement roofing materials have been very widely used. As this cement roofing material, there is a so-called thick roof tile in which uneven ridges rich in surface undulation are formed. By supplying the reduced cement mixture, shaping the surface of the cement mixture on this pallet with rolls and slippers to shape it into a product shape, then curing this shaped body together with the pallet into a product by the roll slipper molding method A molding method is adopted (for example, JP-A-3-57603 and JP-A-2-185407). This molding method
It is mainly used for molding products that are relatively thick plate-like products and that have surface irregularities.

[0003]

However, in the case of the above molding method,
If the unevenness of the cross-sectional shape of the roof tile to be formed is large,
When compression molding is performed with a forming roll at a time, the compression density mainly in the vicinity of the roof protrusion of the roof tile decreases due to the difference in height between the concave portion and the convex portion and the difference in peripheral speed of the forming roll, resulting in low strength. Has the drawback that it may cause a crack in the foot.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a method for molding a cement roof tile in which the overall strength of the recesses and projections of a roof tile having deep irregularities can be made uniform. It was made for the purpose.

[0005]

That is, the method for forming cement tile according to the present invention is such that a cement compound supply hopper is provided on a pallet conveyor serving as a product lower mold, and the surface of the cement mixture supplied is formed by a forming roller. In a method for forming cement roof tiles by pressing to shape a predetermined surface shape into a product, when the surface of the cement mixture on the pallet conveyor is compression-molded by a forming roll, first the convex portion that does not reach the target convex portion of the product surface It is characterized in that it is compression-molded by a pre-molding roll for forming a part, and then is compression-molded by a forming roll for forming a target convex portion.

[0006]

In the present invention, when molding a roof tile having a desired uneven portion, the shaping is performed by forming the convex portion with the preforming roll and then forming the convex portion with the desired shape by the forming roll. Therefore, as compared with the case where the convex portion is molded with the molding roll at a time, the convex portion of the product surface is molded step by step.
The difference in material compressibility due to the difference in height of irregularities and the difference in peripheral speed becomes small, and the degree of compression around the top of the convex portion is the same as that of other smooth portions.

[0007]

Embodiments of the present invention will be described below. 1 is a side sectional view of an apparatus for carrying out the method of the present invention, FIG. 2 is a front view of a preforming roll, and FIG. 3 is a front view of a forming roll.
A cement hopper 3 for supplying a cement mixture 2 is provided on a pallet conveyor 1 serving as a product lower mold, and the cement mixture 1 is supplied.
In the method for forming a cement roof tile in which the surface is pressed by the forming roller 4 to form a predetermined surface shape into a product, the target convex portion G1 on the surface of the product G (FIG. 3) is not reached at the front stage of the forming roller 4. A preforming roll 5 that forms a convex portion (height 1.3 times higher than the height of the convex portion of the product) is provided, compression molding is performed by the preforming roll 5, the slipper 6 is used for leveling, and the desired product convex portion is formed in the subsequent stage. It was compressed by the forming roll 4 for forming and was formed by the slipper 7. After curing the above product by autoclave and measuring the product strength in the convex portion, the results shown in Table 1 were obtained.

[0008]

[Table 1]

In Table 1, a comparative example shows a case where a preforming roll is not used and only a direct forming roll is used. As is clear from Table 1, in the case of the example of the present invention, it was found that the difference in strength between the troughs and the peaks of the roof tiles was almost eliminated, and the strength was uniform.

[0010]

As described above, according to the method of the present invention, it is possible to form a uniform density even on uneven portions having height differences, and to form a roof tile that is unlikely to cause stepping cracks. Is possible.

[Brief description of drawings]

FIG. 1 is a side sectional view of an apparatus for carrying out the method of the present invention.

FIG. 2 is a front view of a preforming roll.

FIG. 3 is a front view of a forming roll.

[Explanation of symbols]

 1 Pallet conveyor 2 Cement compound 3 Supply hopper 4 Forming roller 5 Preforming roller 6, 7 Slipper G Product

Claims (1)

Claims: 1. A cement compound supply hopper is provided on a pallet conveyor, which is a product lower mold, and the surface of the cement compound supplied is pressed by a molding roller to form a predetermined surface shape. In the method of forming cement roof tiles as a finished product, when the surface of the cement mixture on the pallet conveyor is compression-molded with a forming roll, first the compression molding is performed with a pre-forming roll that forms a convex portion that does not reach the desired convex portion on the product surface. And then compression-molding with a molding roll that forms the desired convex portion, and a method for molding a cement roof tile.