JPS6410463B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a thin porcelain or mortise tile having a wall thickness of 5 mm or less and a method for manufacturing the same. Conventionally, tiles made of porcelain or terracotta could not be made to have a wall thickness of less than 5 mm. The biggest hurdle in not being able to make the wall thinner was the pressure forming and firing steps in the manufacturing process. To explain this in more detail, when filling conventional clay into a press mold, first, as shown in FIG. A mass 4 of a mass body 3 is filled with clay from a hopper 5. Then, the supply mass body 3 is slid onto the clay filling space 7 formed by the mold frame 1 and the lower die 6, and the clay is dropped and supplied into the space 7, and then the mass The rear end surface 8 of 4 and the shielding plate 9 are used to make the clay smooth by scraping. However, in the above-mentioned conventional clay filling procedure, due to the scooping of the clay by the shielding plate 9 and the rear end surface 8 of the mass 4, the clay is scraped onto the inner surface of the mold frame 1 in the scooping direction (same as the supply direction). The clay becomes dense. This can be illustrated in Figures 2a to 2.
It is as shown in figure f. In other words, each of the above figures shows a total of 6 square-shaped tile bases (before firing) with a nominal dimension of 200 mm on one side made using the conventional porcelain or mortar tile manufacturing method.
This figure shows the results of measuring the clay filling density at 16 predetermined locations (indicated by black dots) in the planar area of each individual tile material. The wall thickness dimensions of each tile base material are sequentially 11 mm, 9 mm, and 7 mm as you move from Figure 2a to Figure 2f.
It is thinner as mm, 5mm, 3mm, and 2mm. The press pressure for molding the tile raw material was unified to 350 kgf/cm ² for all wall thicknesses. In addition, the clay packing density is the porosity (%) measured based on [Method for measuring apparent porosity, water absorption rate, and specific gravity of refractory bricks] specified in JIS R2205.
It is expressed as a number subtracted from 100. Furthermore, the white arrow shown on the left side of FIG. 2a is the direction of the square 4 (see FIG. 1), and is drawn in the same direction in the drawings from FIG. 2a onwards. Figures 2a to 2f show the distribution of clay filling density using contour lines, and as is clear from these contour lines, as the wall thickness of the tile base becomes thinner, the clay filling density decreases. It can be seen that the distribution state of soil filling density shows a tendency to become steeper. Then, a tile base material with a wall thickness of 7 mm (Figure 2c)
Then, the average value of the four points in the central area is 72.69%,
Since the average value of the four corners is 75.54%, the difference in clay filling density between the two remains at 2.85%, which is less than 3%. Therefore, it is predicted that firing will be possible. However, for the tile base material with a wall thickness of 5 mm (Figure 2d), the average value of the four points in the center area is 73.04%, and the average value of the four points in the four corners is 76.16%.
%, the difference in clay filling density between the two exceeds 3% and is 3.12%. Also, the wall thickness is 3mm.
The difference in clay filling density between the 2 mm tile green material (Fig. 2e) and the 2 mm tile material (Fig. 2f) is 4.06% and 4.23%, respectively, showing a tendency to gradually widen. In short, assuming that a tile base material with a wall thickness of less than 5 mm is fired, the fired product will have bulges and side warping to the extent that it cannot be sold as a tile product on the secondary market. It can be easily inferred that cracking may occur in some cases. Furthermore, the mass 4 of the conventional supply mass body 3 is
The volume of the clay is large, and therefore the dimension of the mass 4 in the scooping direction is also large, and the clay supplied to the clay filling space 7 of the press mold due to the segregation of the clay itself within the mass 4. There is a drawback that segregation occurs already during the filling process, which is the cause of the above-mentioned difference in density. Furthermore, conventionally, assuming that the surface side of the tile raw material 10 formed in this way is glazed and then fired, the tile raw material 10 after glazing is
must be transported into the kiln while being stored horizontally in a thin box-shaped sagger (not shown). However, this sagger had the disadvantage that its bottom surface lost its smoothness significantly as it was used more frequently. This, together with the softening of the tile raw material 10 during firing, causes tile curvature such as deco warping and hollow warping in the tile after firing. It is clear that the above-mentioned problem becomes more pronounced as the wall thickness of the tile becomes thinner. Furthermore, if there is a local difference in density in the packing density of the tile raw material 10, the porosity between the clay raw material particles will differ, resulting in a difference in water absorption rate and rate, which will cause the glaze application thickness to be different during glazing. It was also predicted that mold impressions would occur. The present invention has been made in view of the above circumstances, and has a material of porcelain or furuncle,
Also, with the main aim of commercializing thin tiles with a wall thickness of less than 5 mm, among the areas surrounded by intersecting diagonal lines on the back side of the thin tiles, By providing a thin porcelain or mortar tile with recesses in a pair of opposing areas and a manufacturing method thereof, there is no pattern imprint on the glazed surface, and there is no side warping, deco warping, or dent warping. The objective is to obtain this type of thin tile with excellent dimensional accuracy and less deformation. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the porcelain or mortise thin tile of the present invention and its manufacturing method will be explained below based on embodiments shown in the drawings. FIG. 3 is a back view showing a thin tile 13 made of porcelain or erectine having a wall thickness of 5 mm or less according to the present invention. As shown in the figure, this thin tile 13 is located on the back side of the tile, and is located within an area surrounded by intersecting diagonal lines A and B as a supply mass body used during pressure molding of the tile base material, which will be described later. 1 facing in the direction perpendicular to the clay supply direction (see arrow in the figure)
A large number of square and triangular recesses 15 are distributed in the set of regions 14a and 14b when viewed from above. By providing this recess 15, the clay in the areas 14a and 14b is tightened at the same time as the pressure forming, smoothing out the segregation that occurred during filling of the clay, and making the clay in the areas 16a and 16b without the recess 15. Eliminate density differences and make packing density uniform. dent 15
The ratio of the back side of the tile to the total area is 30-45%
It is preferable that the total area of the recesses 15 is 36.5%. dent 15
The reason why the area of the recess 15 is limited to the above range is that if the area of the recess 15 is too small, there will be no effect of tightening the clay, and similar to the conventional case described above, dense and dense parts of the clay will be partially formed. This is because it causes image distortion, side warping, and drumsticks. On the other hand, if the area of the recesses 15 is too large, a difference in packing density will occur in the regions 14a, 14b where the recesses 15 are distributed, which is not preferable. Furthermore, the ratio of the depth of the recess 15 to the tile thickness is also a problem as a cause of the difference in filling density and the cause of mold impression. Therefore, in this thin tile 13, as shown in Fig. 4, the depth _t1 of the recess 15 is set to be in the range of _t1 /t=5 to 30% of the thickness t of the entire tile. ing. This is because if it is more than 30%, impressions will occur, and if it is less than 5%, there will be no tightening effect and it will cause tile deformation. With such a thin tile 13, it is possible to eliminate the difference in packing density that occurs between the regions 14a, 14b and 16a, 16b when the press mold is filled with clay by the supply mass body. It is possible to make it uniform, to have little deformation such as side warping, deco warping, hollow warping, etc., and to obtain a product with no pattern impressions. Next, a method of manufacturing this thin tile 13 will be explained. Figure 5 shows the clay supply device 17 and press mold 1.
8. The clay supply device 17 includes a bed 20 that is continuous with the lifting stop position of the mold frame 19 that can be raised and lowered, a supply mass body 21 that is slidable on the mold frame 19 and the bed 20, and a supply mass body 21 that is slidable on the mold frame 19 and the bed 20. a hopper 23 for supplying clay into the mass 22;
It is comprised of a chute 24 for supplying clay to the hopper 23. As shown in FIG. 6, the supply mass body 21 has the above-mentioned mass 22 for accommodating the clay on the bed 20, and a shielding plate 25 which is one member constituting the mass 22.
Note that the supply mass body 21 in FIG.
This is for molding pieces. In the supply mass body 21, the volume of the mass 22 is limited to be within a range of 1.0 to 1.2 times the amount of clay equivalent to one thin tile 13 to be obtained. . Currently, the nominal size of one side is 200mm (actually
197.50±1.00) square shaped thin tile 13
The reason for the above numerical limitation will be explained by taking as an example the case of manufacturing. First, as shown in Fig. 10, on the back side of the thin tile 13 to be obtained (the recess 15 is omitted), the upper side is a, the right side is b, and the lower side is c, and let the left side be d. FIG. 11 shows that by changing the width dimension w ₁ in the mass 22 (see FIG. 6) of the supply mass body 21 in the same direction as the clay supply direction, the mass volume required for forming the thin tile 13 can be changed. For standard amount of clay
A line graph showing the finished dimensions of each side of the thin tile 13 made by firing the tile base obtained by increasing the size by 1.0 times, 1.1 times, and 1.2 times. It is. In addition, in the square 22, the width dimension w ₂ in the direction perpendicular to the width dimension w ₁
was kept constant, with the same length as the side length of the tile. In addition, 100 specimens were manufactured each using clay that had passed through a 12-mesh sieve and when using clay that had passed through a 20-mesh sieve. , the average value is shown. As is clear from FIG. 11, when the mass volume of the supply mass body 21 is increased by 1.1 times, the length of the a side of the thin tile 13 is equal to the allowable value of the length of one side of the tile. is 198.50mm
At 1.2 times, it tended to slightly exceed this allowable value. Therefore, the supply mass body 21
It is clear that it is undesirable for the mass volume to exceed 1.2 times. The reason for this is that the difference in the density of the clay in the filling space 27 formed by the mold frame 19 and the lower mold 26 becomes large when filling the clay (see Fig. 5), which will be described later. It is listed as number one. Moreover, when the width dimension ω ₁ of the mass 22 increases,
One of the factors is that the clay is segregated within the mass 22 during the feeding operation of the supply mass body 21, making it difficult to uniformly fill the filling space 27 with clay.
Regarding the width w ₁ of the supply mass body 21, to give a specific value, when the thickness of the thin tile 13 is set to 3 mm, around 25 mm is optimal. Note that the thin tile 13 obtained as described above
The following table summarizes the results of measuring the drumstick, warping, distortion, and side warping of the specimens and calculating the average values. In the table, the (+) symbol attached to the warpage value indicates that the warp was convex towards the front side of the tile, and the (-) symbol attached to the warp value indicates that it was concave towards the back side of the tile. represent. Similarly, the (-) symbol attached to the side warpage value indicates that the side was concave from the corner to the center. As is clear from this table, it can be seen that the thin tile according to the present invention has extremely high dimensional accuracy as a tile product in terms of burr, warpage, distortion, and side warping.

[Table] For reference, the width dimension corresponding to the above w ₁ in a conventional supply mass body is 200 mm even when obtaining a 100 mm square tile with a thickness of 5 mm, and the width of the conventional supply mass body is 200 mm. Soil segregation was significant. On the other hand, the press mold 18 includes a lower mold 26 as a tile back molding mold, a mold frame 19 for forming a clay filling space 27 with the lower mold 26, and an upper mold 28.
It becomes more. The molding surface of the lower mold 26 has protrusions 2 for forming the recesses 15 on the back side of the tile as shown in FIG.
9 are similarly arranged. The operation of pressure-forming the tiles using the clay supply device 17 and the press die 18 configured as described above and the processing steps after molding are as follows. That is, first, the chute 24 is oscillated in the left-right direction as shown in FIG. 7, and the clay is uniformly supplied into the hopper 23 by slightly opening the shutter 30 of the hopper 23 (see FIG. 5). 22 evenly. Then, the supply mass body 21 is slid to the left in FIG. 5, and the tile green material formed in the previous pressure molding is pushed out and demolded using the shielding plate 25 attached to the front surface on the sliding direction side. , and transported to the heating and drying process before glazing, which will be described later. At this time, the pressure-molded tile raw material is pushed up by the lower die 26, and its back side is at the same level as the upper surface of the mold frame 19. After the tile raw material is carried out, the lower mold 26 returns to its lowered position and waits. Thus, the supply mass body 21 has its mass 22 during the above sliding.
When passing over the clay filling space 27 formed by the mold frame 19 and the lower mold 26, the clay contained in the mass 22 is dropped and supplied into the space 27, and at the same time, the clay is Do this. This supply mass body 21
In this case, the size and shape of the mass 22 are limited as described above, and the supply of the clay into the filling space 27 is made uniform as described above. After the supply mass body 21 retreats and returns, the upper die 28 descends and pressurizes the clay in the space 27 to form a tile blank having a recess 15 in the shape shown in FIG. 3 on the back surface. Note that the lower die 2 for forming the recess 15
It is also possible to provide the protrusions 29 provided on the upper mold 28 on the upper mold 28 and use the upper mold 28 as a mold for forming the back surface of the tile. After the upper die 28 returns to its upward position, the above-described operations are repeated to continuously form the tile blank. The tile raw material carried out from the press die 18 by the shielding plate 25 of the supply mass body 21 is glazed by a conveying device 31 (see FIGS. 8 and 9) such as a continuous caterpillar chain. While being sent to a process, it is heated by a heater 32 disposed close to an upper position midway through the process.
This heating is applied during the glazing process when the tile base material reaches 100%
This is done to maintain a temperature of ~200°C. The heated tile base 33 has an increased water absorption capacity, and when glazed in this state, the liquid of the glaze quickly penetrates into the base, and after penetrating, it dries quickly, which is ideal. A beautiful glaze can be obtained, and there is no need to worry about deco warping or glaze peeling. After glazing, the tile blank is placed flat on a conveyor such as a belt conveyor and transported to a roller hearth kiln, tunnel kiln, etc., where it is heated in a temperature range of 1000 to 1250°C for 20 to 60 minutes. Firing is performed in As a result, a thin tile 13 shown in FIG. 3 is obtained. In this type of firing, a sagger is not used as in the past, so the tile base 33 is affected by the smoothness of the bottom of the sagger, which has been lost due to the increased frequency of use. There is no problem, and you can bake with peace of mind. By the way, regarding firing, bisque firing may be performed immediately after the above-mentioned demolding, and the subsequent steps may be performed in the same manner as described above to obtain the thin tile 13. In addition, in the above-mentioned embodiment, the recess 15 provided on the back surface of the thin tile 13 has a square shape and a triangular shape when viewed from above, but the present invention is not limited to this. In some cases, a triangular shape or a circular shape may be provided individually, or a combination of these may be provided as appropriate.
Further, even if the back mold for forming the recess 15 is the lower mold 26 as described above, the upper mold 2
It may be 8. As explained above, according to the present invention, it has become possible to commercialize a thin porcelain or mulberry tile having a wall thickness of 5 mm or less. In addition, in manufacturing it, the size of the supply mass body was limited and the tile back mold was provided with convexities with a specific distribution, so that the filling density of the clay of the tile base material was uniform. It is possible to manufacture tiles with excellent dimensional accuracy and free from tile deformations such as side warping, deco warping, and hollow warping. Also, there is no risk of copying. This effect is particularly noticeable in large, thin tiles where the filling density of the clay tends to vary, and the value of the product is great. Furthermore, in the present invention, the tile raw material is heated and dried at 100 to 200°C before being glazed, so that an ideal glaze can be obtained and there is no need to worry about deco warping or glaze peeling. Furthermore, no sagger is used during firing, and the tile base material is not affected by the flatness of the sagger.

[Brief explanation of the drawing]

Fig. 1 is a drawing showing a conventional clay supply device and a press mold, and Figs. 2a to 2f show tile blanks with different wall thicknesses formed by the conventional manufacturing method. Figures 3 to 9 show the results of measuring the clay packing density at 16 locations, and Figures 3 to 9 relate to the present invention, and Figure 3 shows an example of a thin tile made of porcelain or mortar. 4 is a partial vertical sectional view of FIG. 3, FIG. 5 is a drawing showing the clay supply device and press mold, FIG. 6 is a perspective view of the supply mass body, and FIG. 7 is a mold. A perspective view showing the relationship between the frame, the supply mass body, the hopper, and the chute, FIG. 8 is a front view showing the conveyance device after demolding, FIG. 9 is a longitudinal sectional view of the main part of FIG. 8, and FIG. 10 is a thin FIG. 11 is a schematic back view showing the side codes of the shaped tiles, and is a line graph showing the results of measuring the length of one side of the thin tile specimen. 13...Porcelain or furuncle thin tile, 1
5...Concave, 29...Protrusion, 18...Press mold,
27... Filling space, 22... Mass, 21... Supply mass body.

Claims (1)

[Scope of Claims] 1. In a thin porcelain or mortise tile having a wall thickness of 5 mm or less, a depression is formed in a pair of opposing regions among the regions surrounded by intersecting diagonal lines on the back side thereof. A thin porcelain or furuncle tile characterized by being distributed in a distributed manner. 2. In a space for filling tile powder raw material formed by a mold frame and a lower mold of a press mold having a back mold formed by distributing protrusions in a pair of opposing areas surrounded by cross-diagonal lines, A supply mass body having a mass capable of accommodating 1 to 1.2 times the amount of clay equivalent to one tile is placed in a direction perpendicular to the direction of the facing area in which the protrusions of the back mold are distributed. The clay is filled by the operation, and then the clay is pressure-molded using the above-mentioned press mold, and the resulting tile green material after demolding is heated and dried at 100 to 200°C to form the tile. A tile that has a wall thickness of 5 mm or less by applying a glaze to the surface of the green base material and baking the green tile base once after the glaze has dried, or by firing it twice including the bisque firing process immediately after demolding. A method for manufacturing thin porcelain or mulchite tiles that obtains.