JPH04353402A - Manufacture of large tile - Google Patents

Abstract

PURPOSE:To restrain error in shape and dimension, and deformation from being generated due to uneven heating and cooling by a method wherein the front surface and rear surface of a tile are evenly heated and cooled in a method for manufacturing a tile wherein tiles are formed by extrusion with two tiles being superposed face to face and thereafter said tiles in superposed state are dried, fired, and separated. CONSTITUTION:When two tiles 10 are formed by extusion in a superposed, face to face, state, a plurality of space holding parts 12, which have a predetermined height in the thickness direction of the tile 10 and are disposed at predetermined intervals in the width direction of the tile, are extruded integrally with the tiles 10 to form a formed body, which body is cut to a predetermined length and then dried and fired and thereafter the parts 12 are removed to obtain separated tiles 10.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing large tiles, and more particularly to a method for manufacturing tiles using an extrusion molding method as a tile forming method.

[Background of the Invention] Tiles are generally manufactured by molding raw clay into a predetermined shape, then drying and firing. As a molding method, generally adopted is a method of extrusion molding two tiles together in a substantially intimate state.

[0003]The tile molded product, which is extruded in two pieces, is then cut into a predetermined length and then cut into two pieces.
The sheets are dried and fired in their assembled state.

By the way, especially in the case of large tiles, for example thick and large tiles with a short side of 200 mm or more and a thickness of 20 mm or more, if the two tiles are baked in a close contact state as described above, the tile surface will be damaged. The way the fire circulates in the firing furnace, that is, the way heat is applied, differs between the sides and the back side (the back sides of two tiles are in close contact with each other), so firing is not done evenly. There is no problem.

[0005] Also, as the tile is being cooled, there is a difference in the cooling rate between the front side and the back side, and so-called "cooling breaks" occur in the tile due to the difference in cooling rate. This causes problems such as product defects and a decrease in material yield.

[0006] Furthermore, when extruding tiles, there is a difference in extrusion speed between the outer periphery and the center of the extrusion die (the extrusion speed is faster at the center). It makes a difference. That is, the density is high on the front side of the tile, and the density is low on the back side (the center side of the two-piece molded product).

[0007] As a result, there is a difference in the amount of shrinkage between the front side and the back side of the tile during drying and firing, resulting in problems such as warpage and other deformation of the tile.

In addition, when extruding tiles, undesirable flow and orientation of the raw clay may occur inside the extrusion cylinder or at the extrusion die.
There is a problem that this causes so-called kinks during extrusion and remains in the molded product, and this kinks are particularly noticeable in the center of the die, causing problems such as later deformation of the tile.

[0009]

[Means for Solving the Problems] The present invention has been made to solve the above-mentioned problems, and its gist is to extrude each tile into a combination of two tiles. A plurality of spacing parts having a predetermined height in the thickness direction and arranged at predetermined intervals in the width direction of the tile are extruded together with them interposed therebetween, and the extruded product is cut into a predetermined length. After drying and firing, the spacer is removed and the tiles are separated into tiles.

[Operations and Effects of the Invention] As described above, in the present invention, two tiles are extrusion-molded with a spacer interposed between them. According to this method, a predetermined gap is created between the tiles, so when firing in this state, heat can circulate well not only to the front side of the tile but also to the back side of the tile. The firing conditions are equalized on the front side and the back side. This allows for better firing of the tiles.

[0011] Also, during cooling, this gap allows not only the front side of the tile but also the back side to be sufficiently cooled, and there is no difference in the cooling rate between the front side and the back side, thereby preventing the above-mentioned cooling failure. . This reduces the defective rate of tiles and improves yield.

According to the present invention, the difference in density between the front side and the back side of the tile is reduced. This is because when a tile is extrusion molded according to the present invention, the center portion of the molded body becomes a cavity (gap). .

[0013] As the density difference between the front side and the back side of the tile decreases, the amount of shrinkage during drying and firing becomes similar between the front side and the back side, and therefore, the shrinkage amount due to the difference in shrinkage amount becomes similar. Deformation such as warping is also suppressed.

[0014] According to the present invention, the center portion of the molded body, where the above-mentioned problems such as flow and orientation of the raw material clay are particularly likely to occur during extrusion, is formed as a hollow portion, so that the problems caused by such problems can be avoided. This also has the effect of suppressing the deformation of the tiles.

[0015]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings. In FIG. 2, 10 is a product tile, which is a thick and large tile with a short side length of 200 mm or more and a thickness of 20 mm or more.

[0016] This tile 10 is obtained by extrusion molding two pieces of raw clay together, cutting them into a predetermined length, drying and firing the two pieces together, and then separating them into individual tiles. It will be done.

FIG. 1 shows the cross-sectional structure of a molded product obtained by extrusion molding two tiles together. In the figure, reference numeral 11 denotes a molded body, and each back surface side of the tile 10 is connected by a spacer 12.

[0018] The spacing holding portions 12 have a predetermined height in the tile thickness direction, and are provided in plurality at predetermined intervals in the tile width direction. Note that these spacing sections 12 are separated and removed from each tile 10 after firing.

When the tiles 10 are extrusion-molded in such a two-ply form, when the two-ply tiles are fired, the gaps 14 are formed between each tile 10, so that the tiles 10 Heat is sufficiently distributed to the back side of the tile, so that both the front side and the back side (side of the spacer 12) of the tile are heated almost equally, and firing proceeds under almost equal conditions.

Also, during cooling, due to the presence of this gap 14, cooling proceeds at the same speed on both the front and back sides, thereby preventing the occurrence of cuts due to differences in cooling rates.

[0021] Also, the center part of the extrusion molded body 11 has a gap 14.
Since the tile 10 is molded as a tile 10, the density difference between the front side and the back side of the tile 10 is reduced, and deformation such as warping caused by the density difference is also suppressed.

[0022] Furthermore, the molded product 11 tends to have curls during extrusion.
Since the center portion of the material is a hollow portion, deformation caused by such extrusion habits is also suppressed.

Although the embodiments of the present invention have been described in detail above, this is merely an example. For example, the shape of the spacer 12 is not limited to the above-mentioned shape, and may have a round cross section or other various shapes.

Furthermore, the present invention can be applied to tiles of various sizes and shapes other than the above examples, and the present invention can be modified in various ways based on the knowledge of those skilled in the art without departing from the spirit thereof. It can be implemented in additional ways.

[Brief explanation of the drawing]

FIG. 1 is a diagram illustrating the main steps of a manufacturing method that is an embodiment of the present invention.

FIG. 2 is a perspective view of a tile obtained by the method.

[Explanation of symbols]

10 tiles 11 Molded object 12 Spacing holding part 14 Gap

Claims (1)

[Claims] Claim 1: When extrusion molding two tiles together, each tile is provided with a plurality of spacing sections having a predetermined height in the thickness direction of the tile and arranged at predetermined intervals in the width direction of the tile. A large-sized product characterized by extrusion-molding the two together with the two interposed in the middle, cutting the extrusion-molded body into a predetermined length, drying and firing, and then removing the spacer and separating the tiles into individual tiles. Method of manufacturing tiles.