JPH0924509A - Tile manufacturing method - Google Patents

Abstract

(57) Abstract: In dry molding of tiles, density unevenness of a molded product is prevented, and tiles having a predetermined size and shape are manufactured with high yield. SOLUTION: On the other side of the upper surface of the lower mold where the filling density of the kneaded material is low (the moving side of the powder mass), a convex portion is provided at a position other than the edge portion, and the back surface of the molded body is formed. Out of
The concave portion 4a, which is on the other side and other than the edge portion,
4b is formed, and the thickness of this portion is made smaller than that on one side where the packing density of the kneaded clay is high (the side from which the powder mass moves). The thickness of all edges of the molded body is approximately the same. Alternatively, the upper surface of the lower mold and the lower surface of the upper mold are inclined surfaces that are inclined downward toward the other side. [Effect] With a normal mold, a molded product having a uniform density can be obtained without causing a problem of thickness difference. Prevents dimensional or shape defects, cracks, etc. due to shrinkage difference during firing,
A product having a desired size and shape can be manufactured with high yield.

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 tiles, and more particularly, in manufacturing tiles by a dry molding method, it prevents uneven density of a molded product and manufactures tiles having a predetermined size and shape with high yield. On how to do.

[0002]

2. Description of the Related Art A conventional dry molding method for tiles will be described with reference to FIG. In the figure, 11 is a mold having a molding hole 12 that penetrates vertically, 13 is a lower mold, 14 is an upper mold,
15 is a powdered mass. The powder mass 15 is movable along the upper surface of the mold frame 13.

In molding, first, a lower mold 13 is inserted into a molding hole 12 of a mold frame 11 from below, and a powder mass 15 is directed from one side 11A of the mold frame 11 toward the other side 11B. After moving to the forming hole 12 and supplying the kneaded material S in the powder mass 15 into the forming hole 12, the powder mass 15 is retracted from the forming hole 12 to the original position (FIG. 5 (a),
(B)). Next, the upper mold 14 is lowered and inserted into the forming hole 12 to press-form the kneaded material S (FIG. 5 (c)).
After the molding, the upper mold 14 is raised and the lower mold 13 is raised to take out the molded body 16 (Fig. 5 (d)).

When the tile is molded in this manner, appropriate irregularities are provided on the surface contacting the molded product of the lower mold or the upper mold, and concave grooves are provided on the back surface as shown in FIG. Then, the tile molded body 16 in which the back foot 16a is formed between the concave grooves may be molded.

In such a dry molding method of tiles, the powder mass 15 is moved from one side 11A of the mold 11 to the other side 11B to supply the kneaded clay S, so that the mold 11 is removed. Filling unevenness occurs in the kneaded clay S supplied into the molding hole 12, and a portion of the molding hole 12 near one side 11A of the mold frame 11 from which the powder mass 15 is moved (FIG. 5B). Of S ₁ ) of the mold mass 15 is high, and the density of the powder mass 15 is low at a part of the mold frame 11 near the other side 11B (S ₂ part of FIG. 5B). Often.

By the way, when a compact is fired, shrinkage occurs during firing, but the shrinkage during firing is small in the high-density compact and large in the low-density compact.

Actually, the amount of oil that the compact absorbs the packing density of the porcelain kneaded clay (oil absorption: the higher the oil absorption, the lower the density of the compact, and the lower the oil absorption, the higher the density of the compact. The density is shown in Table 1.), and the relationship between the oil absorption rate and the shrinkage rate at the time of firing was examined. The results are as shown in Table 1 below. You know that it will occur.

[0008]

[Table 1]

Therefore, for example, FIGS. 5 (a) to (d) are shown.
When a tile molded body 16 having a square shape in plan view as shown in FIG. 6 (a) is molded by the above method and the molded body 16 is fired, one of the mold frames 11 of the molded body 16 is The portion 16A on the side 11A side has a high packing density, so the shrinkage during firing is small, and the portion 16B on the side 11B side on the other side of the mold 11 has a low packing density, so the shrinkage during firing is large. Therefore, as shown in FIG. 6 (b), the resulting fired tile 17 has a substantially trapezoidal shape in plan view due to the difference in shrinkage.

Further, since the shrinkage rate of the molded body is partially different, there is a problem that cracks are generated due to the partial shrinkage difference during firing.

In order to solve such a problem, conventionally,
The following methods are used.

When the kneaded material is supplied to the forming holes, the kneaded material is additionally supplied to the portion where the packing density is low.

As shown in FIG. 7 (a), an upper mold 18 whose lower surface inclines downward toward the side S ₂ where the filling density of the kneaded clay S is low is used, and the portion S ₂ where the filling density is low is more strongly added. By pressing, a molded body 19 having a uniform density as a whole is obtained (in FIG. 7 (a), members having the same functions as those shown in FIG. 5 are designated by the same reference numerals).

As shown in FIG. 8 (a), a compact 20 having a trapezoidal shape in plan view is formed by short sides of the high packing density side 20 A and long sides of the low packing density side 20 B. Due to the difference in shrinkage, as shown in FIG. 8B, a fired tile 21 having a square shape in plan view is obtained.

[0015]

Among the above methods (1) to (3), since it is necessary to separately supply the kneaded material after the kneaded material is supplied by the powder mass, it takes time and labor and the productivity is poor.

In the method (1), as shown in FIG. 7 (b),
The obtained molded body 19 has a thin portion where the pressing force is large and a thick portion where the pressing force is small during press molding. Therefore, due to this difference in thickness, there is a possibility that the thickness of the product may deviate from the standard. Further, if the pressure is adjusted within the range that does not meet the standard, the packing density may not be uniform.

In the method (1), it is necessary to provide a mold frame having a trapezoidal molding hole in plan view, and the structure of the mold frame becomes complicated. Moreover, since the difference in shrinkage during firing is not eliminated, the problem of cracking due to the difference in shrinkage cannot be solved.

The present invention solves the above-mentioned conventional problems, and does not change the shape of the molding hole of the mold frame, and does not cause the problem of the thickness difference, when the tile is dry-molded, it is possible to obtain the kneaded material. An object of the present invention is to provide a method for producing a tile having a desired size and shape by preventing unevenness in the density of a molded product due to uneven filling.

[0019]

A method for manufacturing a tile according to claims 1 and 3 comprises: a mold having a molding hole extending vertically;
Using a lower die inserted into the forming hole from below, an upper die inserted into the forming hole from above, and a powder mass movable along the upper surface of the mold frame, The upper surface of the mold is moved from one side of the mold to the other side above the molding hole to supply the kneaded material in the powder mass into the molding hole, and then the powder mass is molded into the molding hole. A method for manufacturing a tile, comprising a step of press-molding a kneaded material by inserting an upper die into the molding hole after retreating from the top of the hole, wherein the thickness of the obtained molded body is at the other side. In the method of manufacturing a tile that is smaller than one side, a convex portion is provided on a portion other than the edge portion on the other side of the lower die upper surface or the upper die lower surface, A concave portion is formed on the back surface or the front surface of the other side, which is the other side and other than the edge. The thickness of the relevant section smaller than the side of the one, characterized in that it substantially the same as the thickness of the edge of the one side of the thickness of the edge of the other side of the molded article.

According to this method, of the kneaded material supplied into the forming holes, the portion on the other side having a low packing density is pressed so as to have a small thickness, so that the density of this portion is increased and the firing is performed. The difference in shrinkage at the time can be eliminated, but in that case, since the thickness of the edges of the molded body can be made substantially the same as the entire molded body, the difference in thickness does not pose a problem.

The tile manufacturing method according to claim 2 or 4 is the method for manufacturing tiles according to claim 1 or 3, wherein a plurality of the convex portions are provided on the other side of the upper surface of the lower mold or the lower surface of the upper mold, and A flat surface that is substantially flush with the edge is provided between the recesses to form a plurality of recesses on the back surface or the front surface of the molded body, and the thickness of the molded body in the portion between the recesses is set to the edge. It is characterized in that it is approximately the same as the thickness of the molded body in the section.

According to this method, a portion having a thickness substantially the same as the edge portion is partially molded on the other side of the molded body having a reduced thickness, and the problem of the thickness difference is further reduced. It

In the method for manufacturing a tile according to a fifth aspect of the present invention, a mold having a molding hole that penetrates vertically, a lower mold inserted into the molding hole from below, and an upper mold inserted into the molding hole from above. A mold and a powder mass movable along the upper surface of the mold frame are used, and the powder mass is formed on the upper surface of the mold frame from one side of the mold frame to the other side of the molding hole. The kneaded material in the powder mass is fed into the forming hole, the powder mass is retracted from the forming hole, and then the upper die is inserted into the forming hole to press the kneaded material. In the method for manufacturing a tile having a step of forming, the upper surface of the lower mold and the lower surface of the upper mold are inclined surfaces that are inclined downward from the one side toward the other side.

According to this method, since the upper surface of the lower mold is inclined downward toward the other side where the packing density is low, a large amount of kneaded clay can be filled. In addition, since the lower surface of the upper mold is also inclined downward toward the other side, it is possible to press-mold this portion with a large pressure to increase the density. At that time, since the upper surface of the lower mold and the lower surface of the upper mold both have a downward inclination, it is possible to prevent a difference in thickness between the molded bodies.

The method of manufacturing a tile according to claim 6 is the method according to claim 5.
In, the downward inclination angle α of the upper surface of the lower mold is 0.01
~ 1.00 °, and the downward inclination angle β of the lower surface of the upper mold
Is 0.01 to 2.00 °, and the angle β is 0.5 to 2 times the angle α.

According to this method, it is possible to effectively eliminate the difference in the density of the molded body due to uneven filling and to make the difference in the thickness extremely small.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 (a) is a sectional view for explaining a method of an embodiment of the tile manufacturing method of the first aspect. FIG. 1 (b) is a cross-sectional view of a fired tile obtained by firing a tile molded body manufactured by the method shown in FIG. 1 (a), and is a sectional view taken along line B- of FIG. 2 and FIG. 3 described later. It corresponds to a sectional view taken along line B. 2 and 3 are perspective views showing the back surface of the fired tile manufactured by the method for manufacturing a tile according to claim 1.

FIG. 4 (a) is a sectional view for explaining an embodiment of the method for manufacturing a tile according to claim 3, and FIG. 4 (b) is a tile manufactured by the method shown in FIG. 4 (a). It is sectional drawing of the baking tile obtained by baking a molded object.

In FIGS. 1 to 4, members having the same functions as those shown in FIG. 5 are designated by the same reference numerals.

In the present specification, the moving side of the powder mass having a high packing density of the kneaded clay is referred to as "one side",
The side to which the powder mass moves, where the filling density of the kneaded clay is low, is referred to as the "other side".

In the method shown in FIG. 1 (a), as the lower mold 1, one having a convex portion 2 provided on the other side 1A of the upper surface except the edge portion 1B is used. It is press-formed according to the usual method and is then fired, as shown in FIG. 1 (b).
As shown in FIG.
The recessed portion 4 is formed in a portion other than the edge portion 3B to manufacture the fired tile 3 in which the thickness of this portion is smaller than that of the one side 3B.

The present embodiment relates to a method for manufacturing a tile having a back foot formed on the back surface thereof. The lower mold 1 has an upper surface 1a and a concave groove between the ridges serving as the foot on the back surface of the obtained tile. As shown in FIG. 2, the protrusions 2a and 2b are continuously formed on the protrusions 1b for forming, and as shown in FIG. The recesses 4a and 4b continuous with the recessed groove 3b are formed.

The concave portions 4a and 4b are not limited to those formed on the other side of the other side of the fired tile except the edge portion, and as shown in FIG.
Instead of forming a recess in the book 3a 'or some of the books, a flat surface may be provided on the other side 3A with a portion having a thickness substantially the same as the thickness of the edge 3B.

Such a fired tile 3'has this convex stripe 3
Same as the above using a lower mold in which a flat surface substantially flush with the edge is formed on the upper surface of the lower mold corresponding to the portion a'and a plurality of convex portions separated by this flat surface are formed. It can be manufactured by press molding by the method of.

With such fired tiles 3, 3 ',
The other side 3A is pressed by the convex portion 2 of the lower mold 1 under a large pressing force, so that the density of the other side 3A of the molded body obtained even if the filling density of the kneaded clay is low. It is equal to the density of the portion on one side 3C. Therefore, there is no difference in shrinkage during firing, and a fired tile having a desired size and shape can be manufactured with high yield without causing problems such as cracks.

Since all the edges of the fired tiles 3 and 3'have the same thickness, they do not deviate from the tile thickness standard. The edge 3B of the other side 3A
With regard to the above, even if the thickness is the same as that of the edge portion of one side 3C, the concave portion 4 is formed in the portion adjacent to the edge portion, so that the kneaded material is slightly moved during press molding and is kneaded. Since the packing density of soil is increased, a large difference in shrinkage due to firing does not occur.

The depth and width of the recess formed on the other side of the back surface of the fired tile differ depending on the thickness and area of the fired tile to be manufactured, the shrinkage characteristics of the kneaded clay used, the press molding conditions, etc. In case of thickness 0.20 ~ 5.00m
The area is about 4.5 to 60.0 cm × 4.5 to 90.
When manufacturing a fired tile of about 0 cm, the width of the concave portion formed on the back surface of the fired tile (the value corresponding to w ₁ in FIG. 1 (b)) is the entire width of the fired tile (corresponding to W in FIG. 1). 10% to 60% of the thickness of the fired tile (first value).
It is preferably about 2 to 30% of the value corresponding to D in FIG. In addition, the width of the edge portion on the other side (value corresponding to w ₂ in FIG. 1) is the entire width of the fired tile (W in FIG. 1).
It is preferable to be about 1.5 to 15% of the value (corresponding to

Further, as shown in FIG. 3, the recesses (the portions 3b and 4b) called the back feet are formed, including the case of forming the recesses (the portions 3b and 4b) called the discontinuous foot on the other side. The area of the area to be burned is 30 of the area of the fired tile.
It is preferably set to 70%.

Although FIGS. 1 to 3 show the case where the lower mold having the convex portion formed on the upper surface is used to form the concave portion on the back surface of the molded body, the lower mold is formed on the upper surface. The same effect can be obtained by forming a convex portion similar to the convex portion on the lower surface of the upper mold and forming a concave portion on the surface of the obtained molded body.

In the method shown in FIG. 4 (a), the lower die 5a is an upper die 5 in which the lower surface 5a is an inclined surface that is inclined downward from one side to the other side, and the upper surface 6a is from one side. By using the lower mold 6 having an inclined surface that is inclined downward toward the other side, press molding is performed according to a conventional method, and the obtained molded body is fired, as shown in FIG. 4 (b). , The front surface 7A and the back surface 7B together form a tile molded body 7 that recedes from one side toward the other side.

In the case of such a tile molded body 7, since the upper surface 6a of the lower mold 6 is a downwardly inclined surface from one side toward the other side, the kneading on the other side in the molding hole 12 is performed. The filling amount of the soil S increases. Moreover, in press molding, since the lower surface 5a of the upper die 5 is an inclined surface descending from one side toward the other side,
By pressing the kneaded clay S with a high pressing force, the density is sufficiently increased. Therefore, since there is almost no difference in density between one side and the other side, and there is no difference in shrinkage during firing, it is possible to produce a fired tile of a desired size and shape with good yield without causing problems such as cracks. it can.

As described above, even if the lower surface 5a of the upper die 5 is the downward inclined surface, the upper surface 6a of the lower die 6 is also the downward inclined surface. Therefore, the upper surface shown in FIG. The thickness of the other side of the obtained tile does not become extremely thin as compared with the thickness of one side as in the conventional method using, and the thickness d ₁ of one side of the fired tile and the other side The thickness is substantially equal to the thickness d ₂ on the side of, and does not deviate from the thickness standard.

In this method, the downward inclination angle α of the upper surface of the lower die is 0.01 to 1.00 °, the downward inclination angle β of the lower surface of the upper die is 0.01 to 2.00 °, and the angle β is Angle α
0.5 to 2 times is preferable in terms of reduction of density difference and thickness difference.

[0045]

【Example】

Example 1 Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples.

Example 1 A tile molded body was obtained according to the method shown in FIGS. 1 (a) and 1 (b), and was fired to obtain a fired tile shown in FIG.
The size of the manufactured fired tile was 15 cm × 15 cm × thickness 0.9 cm, and the recess formed on the back surface had the following size.

Width of recess (corresponding to W ₁ in FIG. 1 (b)):
20% of the width of the fired tile Depth of the recess (corresponding to d in FIG. 1 (b)): 20% of the thickness of the fired tile Area of the recess (areas of 4a and 4b in FIG. 1 (b)) :
18% of the area of the fired tile The width of the edge on the other side: 5% of the width of the fired tile About 100 fired tiles obtained, the length L ₁ of the edge on one side and the edge of the other side of the length L ₂ was measured, where the percentage of shrinkage was determined by _{L 1 / L 2, L 1} / L
_A very good value of ₂ = 1.002 (average value of 100 pieces) was obtained. Further, out of 100 fired tiles, none of the fired tiles had cracks due to firing.

Comparative Example 1 A fired tile having the same dimensions as in Example 1 except that the recess was not formed on the back surface and the shrinkage ratio was determined in the same manner. L ₁ / L ₂ = 1.007 ( The average difference of 100 pieces) was large. In addition, out of 100 fired tiles, there were 4 fired tiles that could not be made into a product due to cracking or deformation, and the yield was very poor.

Example 2 A tile molded body was obtained according to the method shown in FIGS. 4 (a) and 4 (b) and was fired to obtain a fired tile. The size of the fired tile produced is 10 cm x 20 cm x thickness 0.55c
m, and the downward inclination angle α of the upper surface of the lower die is α = 0.03 °,
The downward inclination angle β of the lower surface of the upper mold was set to 0.04 °.

The length L ₁ of the edge on one side and the length L ₂ of the edge on the other side of each of 100 obtained fired tiles were measured, and the shrinkage ratio was calculated by L ₁ / L ₂ . As a result, L ₁ / L ₂ = 1.001 (100 average value), which was an extremely good value. Further, out of 100 fired tiles, none of the fired tiles had cracks due to firing.

The ratio d ₂ / d ₁ of the thickness d ₂ of the edge on the other side to the thickness d ₁ of the edge on the one side is 1.0.
It was 06 (average value of 100 pieces), and there was almost no difference in thickness.

Comparative Example 2 The same as in Example 1 except that only the upper mold had a lower inclined surface (downward inclined angle of 0.08 °), and the lower mold had an upper surface having a horizontal surface. Then, a fired tile having the same size was manufactured, and the shrinkage ratio was calculated in the same manner. The shrinkage difference was L ₁ / L ₂ = 1.002, and although the difference in shrinkage was not so large, the thickness of the edge on the other side was The ratio d ₂ / d ₁ between the thickness d ₂ and the thickness d ₁ of the edge on one side is 1.054.
In (average value of 100 pieces), there were some things that could not be made into products due to too large difference in thickness.

[0053]

As described in detail above, according to the tile manufacturing method of the present invention, a molded product having a uniform density can be obtained by using an ordinary mold without causing a problem of thickness difference. it can. Therefore, it is possible to prevent defective size or shape due to difference in shrinkage during firing, cracks and the like, and to manufacture products with desired size and shape with high yield.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view showing a method of manufacturing a tile according to an embodiment of the present invention, and FIG. 1 (b) is FIG. 1 (a).
FIG. 3 is a cross-sectional view of a fired tile obtained by firing the tile formed body manufactured by the method shown in FIG.

FIG. 2 is a cross-sectional view of a tile molded body manufactured by the method shown in FIG. 1 (a).

FIG. 3 is a perspective view showing another embodiment of the tile molded body manufactured by the method of the present invention.

FIG. 4 (a) is a cross-sectional view showing a method of manufacturing a tile according to another embodiment of the present invention, and FIG. 4 (b) is a tile manufactured by the method shown in FIG. 4 (a). It is sectional drawing of the baking tile obtained by baking a molded object.

FIG. 5 is a cross-sectional view showing a conventional dry molding method.

FIG. 6 is a plan view showing shrinkage by firing according to a conventional method.

7 (a) is a cross-sectional view showing a conventional dry molding method, and FIG. 7 (b) is a cross-sectional view of a tile molded body manufactured by the method shown in FIG. 7 (a).

FIG. 8 is a plan view showing a conventional dry molding method.

FIG. 9 is a perspective view showing a back surface of a conventional tile molded body.

[Explanation of symbols]

 1 Lower mold 2,2a, 2b Convex part 3,3 'Firing tile 3a Convex strip 3b Concave groove 4,4a, 4b Recess 5 Upper mold 6 Lower mold 7 Firing tile 11 Mold frame 12 Forming hole 14 Upper mold 15 Powder mass S clay

Claims (6)

[Claims] 1. A mold frame having a molding hole penetrating vertically, a lower mold inserted into the molding hole from below, an upper mold inserted into the molding hole from above, and a mold frame. In the powder mass, the powder mass movable along the upper surface is used to move the powder mass from the one side of the mold to the other side of the upper surface of the mold to the molding hole. Of the tile having a step of feeding the kneaded clay into the forming hole, then retreating the powder mass from the forming hole, and then inserting the upper mold into the forming hole to press-form the kneaded material. A method of manufacturing a tile, wherein the thickness of the obtained molded body is smaller on the other side than on the one side, the tile being on the other side of the upper surface of the lower mold and having an edge. A convex portion is provided at a position other than the above portion, and is the other side of the back surface of the molded body. In addition, a recess is formed at a location other than the edge to make the thickness of the location smaller than that of the one side, and the thickness of the edge of the other side of the molded body is set to the thickness of the edge of the one side. A method for manufacturing a tile, characterized in that the tiles are substantially the same. 2. The plurality of convex portions are provided on the other side of the upper surface of the lower mold, and a flat surface substantially flush with the edge portion is provided between the convex portions according to claim 1. Thus, the plurality of recesses are formed on the back surface of the molded product, and the thickness of the molded product in the portion between the recesses is made substantially the same as the thickness of the molded product in the edge portion. Method. 3. A mold frame having a molding hole that penetrates vertically, a lower mold inserted into the molding hole from below, an upper mold inserted into the molding hole from above, and a mold frame. In the powder mass, the powder mass movable along the upper surface is used to move the powder mass from the one side of the mold to the other side of the upper surface of the mold to the molding hole. Of the tile having a step of feeding the kneaded clay into the forming hole, then retreating the powder mass from the forming hole, and then inserting the upper mold into the forming hole to press-form the kneaded material. A method of manufacturing a tile, wherein the thickness of the obtained molded body is smaller on the other side than on the other side, the tile being on the other side of the lower surface of the upper mold and having an edge. A convex portion is provided at a location other than the above portion, and is the other side of the surface of the molded body. In addition, a recess is formed at a location other than the edge to make the thickness of the location smaller than that of the one side, and the thickness of the edge of the other side of the molded body is set to the thickness of the edge of the one side. A method for manufacturing a tile, characterized in that the tiles are substantially the same. 4. The method according to claim 3, wherein a plurality of convex portions are provided on the other side of the lower surface of the upper mold, and a flat surface substantially flush with the edge portion is provided between the convex portions. Thereby forming a plurality of the recesses on the surface of the molded body and making the thickness of the molded body in the portion between the recesses substantially the same as the thickness of the molded body at the edge portion. Method. 5. A mold frame having a molding hole that penetrates vertically, a lower mold inserted into the molding hole from below, an upper mold inserted into the molding hole from above, and a mold frame. In the powder mass, the powder mass movable along the upper surface is used to move the powder mass from the one side of the mold to the other side of the upper surface of the mold to the molding hole. Of the tile having a step of feeding the kneaded clay into the forming hole, then retreating the powder mass from the forming hole, and then inserting the upper mold into the forming hole to press-form the kneaded material. In the manufacturing method, the upper surface of the lower mold and the lower surface of the upper mold are inclined surfaces that are inclined downward from the one side toward the other side. 6. The downward inclination angle α of the upper surface of the lower mold according to claim 5, wherein the downward inclination angle α is 0.01 to 1.00.
And the downward inclination angle β of the lower surface of the upper mold is 0.01
Is 2.00 °, and the angle β is 0.5 to 2 times the angle α.