JPS63132005A - Manufacture of pottery board and molding die used for said manufacture - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for manufacturing ceramic plates such as tiles, and a mold used therein.

[Conventional technology]

Ceramic plates such as tiles are generally manufactured by compressing frozen soil between an upper mold and a lower mold and firing the molded soil. When manufacturing tiles, etc. using such frozen soil, in order to improve mold release properties, a breathable member is provided on the molding surfaces of the upper and lower molds, and after spraying a mold release agent onto the molding surfaces, the lower mold is A method has been developed in which frozen soil is placed on a mold, the frozen soil is compressed and molded using an upper mold and a lower mold, and after the molding is completed, air is injected through the breathable members of the upper mold and lower mold to release the molded product. (Japanese Unexamined Patent Publication No. 61-64409)
. This method allows for the efficient production of ceramic plates etc. using frozen soil. However, since this method of using frozen soil requires batch work, recently, instead of frozen soil, clay raw materials, felsic raw materials, talc,
A method has been developed in which raw materials such as dolomite lime are appropriately combined to form a wet composition (slurry-like raw material composition) with a high moisture content, and this is then molded. That is, the above-mentioned wet composition is placed in a water-permeable lower mold made of plaster having a molding part, and then an upper mold made of a water-permeable material such as gypsum is attached, water is drained through the mold, and the slurry-like composition is placed in the mold. A molded article is formed from the solids of the wet composition. A method has been developed in which the molded product is sucked using a suction cup or the like, removed from the mold, dried, and then placed in a kiln and fired to produce a ceramic plate such as a tile.

[Problem that the invention seeks to solve]

However, as mentioned above, when draining water using a mold made of a water-permeable material such as gypsum, fine particles distributed in the wet composition may This causes clogging (the voids formed between molecules), which impairs drainage properties and takes a long time to manufacture.At the same time, the molded product obtained becomes higher in moisture content as it is molded more times. However, when demolding, the problem arises that the shape may collapse depending on the case.

If an attempt is made to pressurize the wet composition in order to improve its drainage properties, it is impossible to achieve this because the plaster mold will chip or crack.

In order to solve these problems, the present inventor used a sponge-like body made of rubber, synthetic resin, etc. and equipped with communicating holes, instead of the water-permeable dish-shaped mold used in the wet method, and By pressure-casting a wet composition (slurry-like raw material composition) and draining water by vacuum suction from the surrounding area, a molded product with uniform powder distribution can be obtained in a short time. discovered that an extremely good ceramic plate could be obtained by firing the
No. 7). According to this method, all of the conventional problems as described above can be solved, but even better effects can be obtained if the releasability of the molded product is further improved.

The present invention was made in view of these circumstances, and it provides a ceramic plate with uniform powder distribution and no cracks or cracks.
The purpose of the present invention is to provide a method for manufacturing ceramic plates that can be manufactured more efficiently and a mold for use in the method.

[Means for solving problems]

In order to achieve the above object, the present invention prepares an upper mold and a lower mold, at least one of which is formed of a porous elastic body with continuous pores, and combines the two molds to close the mold. A slurry-like raw material composition is pressure cast into the molding part of at least one of the mold and the lower mold, so that a part of the water in the raw material composition remains in the mold made of the porous elastic body with continuous pores. The raw material composition is suction-dehydrated through the continuous pores of the porous elastic body with continuous pores, and then gas is blown under pressure into the molded part through the continuous pores of the porous elastic body with continuous pores. The first gist is a method for manufacturing a ceramic plate, which is characterized by releasing a molded product and converting it into a ceramic plate, and comprising an upper mold and a lower mold in which a molding part is formed on at least one mold surface, and the above-mentioned method. A raw material casting means is provided for pressure-casting a slurry-like raw material composition into the molding part in a state where both molds are put together and the mold is closed, and at least one of the upper mold and the lower mold is porous with continuous pores. The mold is made of an elastic body and is made of the porous elastic body with continuous pores.
It is sealed in the formwork with the mold surface remaining and the void left open.
A suction means for vacuum suctioning the void in the formwork and a pressurized gas blowing means for blowing pressurized gas into the void in the formwork are provided, and the operation of the suction means and the pressurized gas blowing means is provided. The second aspect is a mold characterized by being provided with a control means for controlling the mold.

That is, in the present invention, one or both of the upper mold and the lower mold are formed of a porous elastic material with continuous pores, and during suction dehydration, part of the moisture in the raw material composition is absorbed by the continuous pores. In order to make the gas remain in the porous elastic body with pores, and then blow the gas under pressure into the molded part through the continuous pores of the porous elastic body with continuous pores,
The moisture remaining in the porous elastic body with continuous pores is ejected toward the outer peripheral surface of the molded object, and the molded object is released from the mold with a water film formed on the outer peripheral surface of the molded object. Therefore, the molded article can be smoothly released from the mold without being deformed. As a result, it becomes possible to extremely efficiently manufacture a 1ltl 6a plate with uniform powder distribution and no cracks or cracks.

The ceramic plate according to the present invention is produced by pressure-casting a wet composition into the molding part of the mold using the above-mentioned special upper mold and lower mold, with both molds brought together and the mold closed, followed by suction dehydration. Then, pressurized gas is blown into the molded product to release it from the mold, and the resulting molded product is fired.

Either or both of the upper mold and the lower mold are formed of a porous elastic material with continuous pores.

When both are not formed of a porous elastic body with continuous pores, and one is formed of a porous elastic body with continuous pores, the other is formed of a sealing body. A molding part such as a molding recess is formed on one or both of the mold surfaces of the upper mold and the lower mold, and the wet composition is pressure-molded in the molding part when the molds are put together. It has become.

As the porous elastic body with continuous pores, a sponge-like body made of rubber or synthetic resin is used. In this case, the sponge-like body must have continuous pores; the effects of the present invention cannot be achieved if the sponge-like body has closed pores. That is, the continuous pores of the sponge-like body serve as a flow path during suction dehydration and pressurized gas blowing, and this flow path is used to drain the wet composition and release the molded product. In this case, the pore diameter of the continuous pores is determined by the drainage property,
This has a great effect on mold releasability, and the pore size is preferably set to be approximately the same size as the voids between gypsum molecules in a water-permeable dish-shaped mold made of gypsum.

A mold made of such a porous elastic material with continuous pores is usually placed in a mold with the mold surface (the surface on which the molded part is formed or the surface facing the molded part) left open while maintaining the voids. The wet composition that is sealed and pressurized into the molding part is dehydrated by vacuum suction in the voids of the mold, and the molded product is released from the mold by blowing pressurized gas into the voids. There is.

As the pressurized gas, pressurized air is usually used, but a pressurized gas such as nitrogen gas may also be used.

As described above, in the mold used in the present invention, either or both of the upper mold and the lower mold are formed of a porous elastic body with continuous pores. When one side is formed of a porous elastic body with continuous pores, the other side is formed of a sealing body. In this case, the shape of the seal body does not matter, such as a plate-like body or a table-like body. When the wet composition in the molding section is sucked and dehydrated through the continuous pores of the one mold made of the porous elastic body with continuous pores, this seal body is used as a mold surface of one of the molds made of the porous elastic body with continuous pores. is sealed so that the suction force during suction dehydration can sufficiently act on the wet composition. Therefore, it may be made of any material as long as it maintains sealing properties; it may be made of an elastic material such as dense rubber or synthetic resin, or it may be made of a rigid material such as metal. It may be composed of the body.

A molding part such as a molding recess for pressure casting a slurry-like raw material composition is usually formed in a mold made of the porous elastic body with continuous pores. However, depending on the case, it may be formed into a mold made of a sealing body. Also, instead of forming it on either the upper mold or the lower mold, it is formed on both molds,
Both molded parts may coincide with each other when the mold is closed.

In addition, instead of providing only one molding section, a plurality of molding sections are provided on one mold surface, and they are communicated with each other via a slurry supply path, so that one molding operation can be performed. A plurality of molded bodies may be obtained.

The wet composition (slurry-like raw material composition) to be pressure cast into the molding part as described above may include the above-mentioned clay raw material, felsic powder raw material made of silica powder, feldspar, etc.
A material obtained by kneading a conventionally known ceramic raw material such as talc by a conventionally known method and adjusting the moisture content as appropriate is used. In this case, since the wet composition is cast into the molded part under pressure, during this casting, the upper mold and lower mold are brought together to close the mold, and the mold is closed. The wet composition is pressure cast into the molding section of the closed mold using a nozzle or the like. At this time, the porous elastic body with continuous pores is deformed by the pressure during pressure casting, and if the bottom of the molding part or the surface of the elastic body is deformed too much, it becomes impossible to obtain a F[device of the predetermined shape. Therefore, as the porous elastic body with continuous pores,
It is preferable to use a relatively hard material such that when a pressure of about 30 kg/cm is applied, the mold surface of the bottom elastic body of the molding recess subsides at a rate of 0.11 or less from the initial state. The wet composition that is pressure cast into the molding part has a moisture content of 20 to 25% by weight (hereinafter abbreviated as "%").
It is preferable to adjust it so that Further, the pressure during the pressure casting is preferably set to 5 to 30 kg/cffl.

That is, by setting the water content and pressure as described above, good water removal properties can be achieved in conjunction with the effect of suction dewatering. The moisture content of the molded product formed after such draining is preferably set to 10 to 15%. That is, if there is a large amount of residual moisture in the molded product, the molded product may be deformed by the pressure when the pressurized gas is blown into the molded product. As a result of leaving moisture in the molded product at the above rate, moisture inevitably remains in the mold made of the porous elastic material with continuous pores, and this residual moisture becomes difficult to release from the mold. By blowing pressurized gas, e.g. pressurized air,
It blows out into the molding part through continuous pores, forms a water film on the surface of the molded product, and releases the molded product from the mold with uniform pressure. Therefore, the molded product can be smoothly and quickly released from the mold without causing deformation or the like. In this case, the blowing pressure is preferably set to a pressure of 0.5 to 15 kg/a, most preferably 2 to 5 kg/a.
cnl. The blowing time is not particularly limited, but is usually about 1 to 45 seconds, and setting it to about 3 to 30 seconds gives good results. In addition, when the residual moisture in the porous elastic body is small or when it is desired to increase the amount of moisture in the pressurized gas to improve the mold release speed, the moisture may be contained in the pressurized gas in the form of dew. will be held.

For example, the molded product obtained in this way has a density of 300 to 50
0°C'? ? After drying for 1 to 3 hours,
Ceramic plates such as tiles can be obtained by firing them in a kiln at a temperature of ℃ or higher. In this case, it is preferable to carry out preliminary drying and preliminary heating for drying and firing to prevent cracks in the molded body, followed by main drying and heating. Ceramic plates such as tiles obtained in this way are
Even when the size is 450 x 450 x 10 inches, no cracks occur, and even when a three-dimensional pattern is formed on the surface, the three-dimensional pattern does not deform at all and is in good condition.

Next, an example of a mold used in the manufacturing method of the present invention is shown in FIG. In the figure, 1 is the lower formwork with a U-shaped cross section;
It is constructed by disposing side plates 3 around a bottom plate 2 and tightening them with bolts 4. Reference numeral 5 denotes a lower mold made of a porous elastic material with continuous pores such as a rubber sponge, which is housed in the lower mold 1, and is provided with crosspieces 7 so that its bottom surface maintains a constant gap 6 with the bottom surface of the lower mold 1. It's more lifted up. 8 is a molding recess. That is, the lower mold 5 is hermetically housed in the lower mold frame 1 with the surface (mold surface) on which the molding recess 8 is formed and the gap 6 maintained. The molding recess 8 is formed on the surface of the lower mold 5 made of the porous elastic material with continuous pores, and the bottom surface thereof is formed into an uneven pattern surface for transferring a three-dimensional pattern. Reference numeral 10 denotes an upper formwork constructed in the same manner as the lower formwork 1, in which, like the lower formwork 1, a gap 6 was maintained between the upper mold 5' made of a porous elastic material with continuous pores and the bottom surface. It is kept in sealed condition. Reference numeral 11 denotes a wet composition tank, in which a wet composition 13 is pressure cast into the molding recess 8 through a vibrator 12.

Reference numeral 14 denotes a suction/discharge vibrator equipped with a three-way valve 16, which vacuum-absorbs the voids 6 of the lower mold frame 1 and the upper mold frame 10 to inject into the molding recess 8 through the continuous pores of the porous elastic material with continuous pores. The molded wet composition 13 is dehydrated by suction, and the three-way valve 16 is switched to send pressurized air into the molding recess 8 to demold the molded product. Reference numeral 15 denotes a gasket, which is attached to the upper end surface of the side plate 3 of the lower formwork 1, and presses against the lower end surface of the side plate 3 of the upper formwork 10 to seal the insides of both the formworks 1 and 10 when the mold is closed. . The three-way valve 16 is provided in the vibrator 14, and by switching the three-way valve 16, the vacuum is evacuated as shown by arrow A, and the wet composition 13 cast into the molding recess 8 is evacuated.
After that, switch the valve 16 and follow the arrow B.
Blow in pressurized air as shown to release the molded product from the lower mold 5, then open the mold, and then blow in pressurized air as shown by arrow B'' to release the molded product from the upper mold 5''. It has become.

In this mold, when the mold is closed as shown in the figure, the wet composition 13 is pressure cast into the molding recess 8 while keeping both molds 5.5" under pressure as shown by arrow C. Then, after suction dehydration as indicated by the arrows above, pressurized air is blown into the upper mold (lower mold) in two stages as shown by arrows B and B.

The molded product is removed from the lower mold (upper mold). In this case, since the mold can perform suction dehydration from both the bottom and top surfaces of the molding recess 8, molding can be carried out in a short time when manufacturing a large ceramic plate using a large amount of wet composition 13. Furthermore, due to the unevenness of the bottom surface of the molding recess 8, a beautiful three-dimensional pattern can be formed on the surface of the tile or the like. Moreover, since the above-mentioned mold release is performed smoothly by blowing pressurized air, the molded product and its beautiful pattern will not be deformed due to the force applied during mold release (force that causes the molded product to peel off from the mold surface). .

In addition, when performing suction dehydration as described above, even if it is performed at a considerable degree of vacuum, the suction force is appropriately relaxed through the continuous pores in the porous elastic body with continuous pores, and the wet process in the molding recess 8 is performed. Added to composition 13. Therefore, the molding of the wet composition 13 is not adversely affected by the suction force during suction dehydration. The same applies to the blowing of pressurized air.

In particular, when producing ceramic plates by the method of the present invention, it is extremely effective for producing large ceramic plates with three-dimensional patterns formed on their surfaces. That is, according to the above method, since the wet composition 13 is used for molding, the powder distribution becomes uniform, and since it is performed by pressure casting and suction dehydration, it can be performed quickly. Furthermore, since the molded product is released from the mold by blowing pressurized gas, it is possible to release the mold smoothly and quickly.Moreover, it is a large ceramic plate with a three-dimensional pattern transferred onto it. The board and pattern will not be deformed.

In the above explanation, both the upper mold 5° and the lower mold 5 are made of porous elastic material with continuous pores, but as shown in FIG. 2, the upper mold 5° is made of rubber, metal plate, etc. Alternatively, only the lower die 5 may be made of a porous elastic body with continuous pores, or the arrangement may be reversed as shown in FIG. 3. In FIGS. 2 and 3, 2a is a crosspiece.

Further, as shown in FIG. 4, the lower mold 5 is made of a porous elastic material with continuous pores, the upper mold 5' is made of a sealing body, and the molding recesses 8 and 5' are formed in both molds 5 and 5'. 8' may be provided so that when the mold is closed, the molding recesses 8 and 8'' meet to form one molding recess 18 as a whole.Alternatively, as shown in FIG. Both the mold 5' and the lower mold 5 are made of porous elastic material with continuous pores, and these are placed in the upper mold 19' and the lower mold 19, which are hollow inside, and the molds 19° and 19 are By forming small holes 19a on the inner surface and performing vacuum suction and blowing pressurized gas into the hollow portion, suction dehydration and pressurization are performed on the entire outer peripheral surface of the porous elastic body 5 with continuous pores. A blowout of gas may also be applied.

〔Effect of the invention〕

As described above, the present invention uses a porous elastic body with continuous pores, forms one or both of an upper mold and a lower mold, and forms a molding part on at least one of the mold surfaces of both molds,
A wet composition is pressure cast into the molded part, and the molded product is dehydrated by suction using the continuous pores so that some of the water in the wet composition remains in the porous elastic body with continuous pores. After that, pressurized gas is blown out from the continuous pores into the molding part along with the residual moisture, and the molded product is thereby released from the mold. Therefore, while achieving a uniform powder distribution using the wet method, water draining is performed. Time can be shortened, and the molded product can be released smoothly and quickly without deforming it. As a result, it has become possible to efficiently manufacture ceramic plates that are strong enough to not break, crack, or otherwise deform, especially large ceramic plates that were almost impossible to manufacture in the past. .

Next, the present invention will be explained in detail based on examples.

〔Example〕

First, a mold for producing tiles as shown in FIG. 1 was prepared. Next, 40 parts by weight of clay raw material (
(hereinafter abbreviated as "part"), 55 parts of felsic powder raw material, and 5 parts of talc, and has a water content of 20 parts.
% was poured into the molding recess 8 of the lower mold 5 from the tank 11 at a pressure of 20 kg/cJ. Next, the composition 13 was drained for 5 minutes by vacuum suction to produce a tile molded product. The moisture content of this molded article was about 15%. Next, first apply 2~ to the lower mold 5.
The molded product is released from the mold surface of the lower mold 5 by blowing air at an air pressure of 4 kg/- for 5 to 15 seconds, and in this state, the upper mold 5 is
゛ was slightly increased. In this state, the molded product remains attached to the mold surface of the upper mold 5'. Next, pressurized air was blown into the upper mold 5'' in the same manner as the lower mold 5 described above. As a result, the molded product was smoothly released from the upper mold 5'. After drying the tile molded product thus obtained at 300 to 500°C for 1 to 3 hours,
It was fired in a firing furnace at a temperature of 1100°C or higher. In this case, drying and firing were carried out by pre-drying and pre-heating so as not to cause cracks in the tile molded product, followed by main drying and heating. The tiles thus obtained had large dimensions of 450 x 450 x lOmm, were beautiful with a three-dimensional pattern formed on the surface, had no cracks or cracks, and were extremely strong. .

In addition, in the above example, a large tile with an uneven pattern formed on the surface is manufactured, but the above example can also be applied to small flat tiles (approximately ioam square) that have been used in the past. It can be manufactured by a similar method, and the same effects as above can be obtained in that case as well.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of one embodiment of the mold used in the present invention, Fig. 2 is a sectional view of another embodiment, Fig. 3 is a sectional view of yet another embodiment, and Fig. 4 is a sectional view of another embodiment. FIG. 5 is a cross-sectional view of yet another embodiment. 1... Lower formwork 5... Lower mold 5゛... Upper mold 8.
...Molding recess 1o...Upper formwork 11...Wet composition tank 13...Wet composition 14...Suction/discharge pipe 16...Three-way valve patent applicant Tokai Rubber Industries Co., Ltd. No. Figure 5

Claims (7)

[Claims] (1) Prepare an upper mold and a lower mold, at least one of which is formed of a porous elastic material with continuous pores, and mold at least one of the upper mold and the lower mold with the molds closed together. A slurry-like raw material composition is pressure cast into the chamber,
Suction dehydrating the raw material composition through the continuous pores of the porous elastic body with continuous pores so that a part of the water in the raw material composition remains in the mold made of the porous elastic body with continuous pores, A method for manufacturing a ceramic plate, characterized in that the molded article is then released from the mold by blowing gas under pressure into the molded part through the continuous pores of the porous elastic body with continuous pores, and the molded article is made into a ceramic plate. (2) The method for manufacturing a ceramic plate according to claim 1, wherein the gas blown into the molding part under pressure contains moisture. (3) The method for producing a ceramic plate according to claim 1 or 2, wherein a concave-convex pattern for transferring the concave-convex pattern is formed on the concave surface of the molding part. (4) The method for producing a ceramic plate according to any one of claims 1 to 3, wherein the porous elastic body with continuous pores is composed of a sponge-like body made of rubber or synthetic resin. (5) The moisture content of the slurry-like raw material composition is 20 to 25
The method for manufacturing a ceramic plate according to any one of claims 1 to 4, wherein the moisture content of the molded product formed by suction dehydration is set to 10 to 15% by weight. (6) Pressure casting of slurry-like raw material composition
A method for manufacturing a ceramic plate according to any one of claims 1 to 5, which is carried out at a pressure of kg/cm^2. (7) An upper mold and a lower mold each having a molding part formed on at least one mold surface, and a slurry-like raw material composition being pressure-injected into the molding part when the molds are closed together. A raw material casting means for molding is provided, at least one of the upper mold and the lower mold is composed of a porous elastic body with continuous pores, and the mold composed of the porous elastic body with continuous pores leaves a mold surface. The mold is hermetically housed in a mold while maintaining a void in the mold, and is provided with a suction means for vacuum suctioning the void in the mold and a pressurized gas blowing means for blowing pressurized gas into the void in the mold, A molding die, further comprising a control means for controlling the operation of the suction means and the pressurized gas blowing means.