JPS6345002A - 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]

There are two methods for manufacturing ceramic plates such as tiles: dry methods and wet methods. The dry method uses a dry powder composition made by appropriately combining clay raw materials and felspar (feldspar, silica, etc.) consisting of fine particles, as well as raw materials such as talc, dolomite, and lime.
A ceramic plate such as a tile can be made by charging the composition into the molding recess of the mold, pressurizing the charged composition with an upper mold made of a flat mold, removing the formed body from the lower mold and firing it. This is a method of manufacturing.

In addition, in the wet method, a wet composition with a predetermined moisture content is prepared by appropriately combining felsic raw materials made of clay raw materials and fine particles as well as raw materials such as talc, dolomite, and lime, which are similar to those used in the dry method. (slurry-like raw material composition),
This composition is placed in a water-permeable dish-shaped mold made of gypsum, and water in the wet composition is drained through the mold to form a molded body made of solid components of the wet composition in the mold. Next, the molded body is removed from the mold by suction using a suction cup or the like, and after drying, the molded body is placed in a kiln and fired to produce a ceramic plate such as a tile.

[Problem that the invention seeks to solve]

Of the two types of manufacturing methods mentioned above, the dry method uses high pressure (350 k
g/cj). Therefore, when making a large-sized product, for example, 30 x 30 cm, a pressurization of 31 st is required, and when making a large product of 600 x 600 cm, a pressurization of 1260 t is required. As a result, the equipment is extremely bulky (in addition, when pressurizing and compacting the dry powder composition, the distribution of the powder becomes uneven and distortion occurs, causing cracks and cracks in the compact). This method has the disadvantage of increasing the number of defective products.

In the wet method, it is sufficient to simply flow the wet composition into a water-permeable dish-shaped mold, so a large pressure is not required, and the distribution of the powder is relatively uniform. However, when draining water using a water-permeable dish-shaped mold, fine particles distributed in the wet composition are removed from the water-permeable dish-shaped water passages (gaps formed between molecules of gypsum). This causes clogging, which impairs drainage properties and takes a long time to manufacture.At the same time, the molded product obtained has a high moisture content as the number of molding increases, and when demolding, sometimes has the disadvantage of being muscular. If an attempt is made to pressurize the wet composition in order to improve such drainage, the water-permeable dish-shaped mold made of gypsum will chip or crack, making it impossible to achieve this.

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 produced efficiently without increasing the size of the device, and a mold for use in the method.

[Means for solving problems]

In order to achieve the above object, the present invention covers a lower mold body including a porous elastic body with continuous pores and a corresponding upper mold body to cover the molding recess, In this state, a slurry-like raw material composition is pressure cast into the molding recess, and the raw material composition is sucked and dehydrated through the continuous pores of the porous elastic body with continuous pores, and the obtained molded product is The first gist is a method for producing a ceramic plate, which is characterized by demolding and turning it into a ceramic plate through a firing process. Between the upper mold body, which has a U-shaped cross section and is removably attached to the lower mold body in alignment with the U-shaped opening, and the bottom surface of the mold body in the upper mold body and the lower mold body, respectively. first and second porous elastic bodies with continuous pores housed with gaps provided therein; a molding recess formed in the surface of the second porous elastic body with continuous pores; A raw material casting means for pressure-casting a slurry-like raw material composition into the molding recess when the mold body is installed, and a vacuum suction for the gap between the mold body and the porous elastic body with continuous pores in both of the mold bodies. The second feature is a mold equipped with a suction means.

That is, the present inventors have found that if a sponge-like body made of rubber, synthetic resin, etc. is used in place of the water-permeable dish-shaped mold made of plaster used in the wet method, the wet composition (slurry-like We conducted a series of studies based on the idea that water could be drained by applying pressure after flowing down the raw material composition. As a result, simply pouring a wet composition and pressurizing it is not enough.
It was found that a sufficient effect of improving drainage could not be obtained. Therefore, as a result of further research, we found that the wet composition was not simply poured down into the molding recesses of the porous elastic material with open pores, such as the sponge, but was cast under pressure, and water was drained under pressure. The present invention was achieved based on the discovery that if vacuum suction is used instead of vacuum suction, the water removal property is extremely improved and a molded body with uniform powder distribution can be obtained in a short time.

The ceramic plate according to the present invention is produced by pressure-casting a wet composition into the molding recesses of a porous elastic body with continuous pores in a lower mold body.
It is obtained by suction dehydration, draining, and firing the obtained molded body.

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, and 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 water passages during suction dehydration, and the wet composition is drained through these water passages. in this case,
The pore size of the continuous pores has a great influence on drainage performance,
It is preferable that the pore diameter is set to be approximately the same as the voids between gypsum molecules in a water-permeable dish-shaped mold made of gypsum.

The wet composition (slurry-like raw material composition) to be pressure cast into the molding recesses of the porous elastic body with continuous pores is as follows:
The above-mentioned clay raw materials, felsic powder raw materials made of silica powder, feldspar, etc., and conventionally known ceramic raw materials such as talc are kneaded by a conventionally known method, and the moisture content is adjusted appropriately. things are used. In this case, the moisture content of the wet composition is preferably adjusted to 20 to 25% by weight (hereinafter abbreviated as "%"). Further, the pressure during the pressure casting is preferably set to 5 to 30 kg/aj. That is, by setting the moisture content and the pressure of pressure casting as described above, good water removal properties can be achieved in combination with the effect of suction dehydration.

As described above, in the present invention, a wet composition is pressure cast, and at that time, the pressure of pressure casting is applied to the porous elastic body with continuous pores. However, if the bottom surface of the molding recess of the elastic body is too greatly deformed by this pressure, a ceramic plate of a predetermined shape cannot be obtained. Therefore, as a porous elastic body with continuous pores, the pressure is 30
It is preferable to set the strength to such a level that, when approximately kg/cut is added, the bottom surface of the molding recess subsides at a rate of 0.1 fin or less from the initial state.

In this way, since the wet composition is cast by applying pressure as described above, the cast wet composition overflows when the molding recess is opened. Therefore, the upper mold body is stacked on top of the open-pore porous elastic body of the lower mold body, the molding recess is covered, and the wet composition is applied into the molding recess using a nozzle or the like. Pressure casting is performed. In this case, the upper mold body is provided with a porous elastic body with continuous pores similar to the lower mold body, and this porous elastic body is placed on the porous elastic body with molding recesses of the lower mold body. It is preferable to do so.

In this case, when suction dewatering is performed in the post-process, dewatering can be performed not only from the bottom side of the molding recess but also from the upper side, and the draining time can be shortened.

In this way, an example of a mold that can perform suction dehydration from both the bottom side and the top side of the molding recess is shown in the first article. In the figure, reference numeral 1 denotes a lower die main body having a U-shaped cross section, and is constructed by disposing side plates 3 around a bottom plate 2 and tightening them with bolts 4. 5 is a porous elastic body with continuous pores such as a rubber sponge housed in the lower mold body 1, and is lifted from the crosspiece 7 so that its bottom surface maintains a constant gap 6 with the bottom surface of the lower mold body 1. is in a state. Reference numeral 8 denotes a molding recess formed on the surface of the porous elastic body 5 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 mold body having the same structure as the lower mold main body 1, which, like the lower mold main body 1, houses a porous elastic body 5 with continuous pores while maintaining a gap 6 between it and the bottom surface. There is. Reference numeral 11 denotes a wet composition tank, in which a wet composition 13 is pressure cast into the molding recess 8 through a pipe 12. 14 is a vacuum suction pipe that vacuum-absorbs the voids 6 of the lower mold body 1 and the upper mold body 10, and enters the molding recess 8 through the continuous pores of the porous elastic body 5 with continuous pores of the mold bodies 1 and 10. The cast wet composition 13 is dehydrated by suction from both the bottom side and the top side.

Reference numeral 15 denotes a gasket, which is attached to the upper end surface of the side Fi 3 of the lower mold main body 1, and presses against the lower end surface of the side plate 3 of the upper mold main body 1o to seal the insides of both mold main bodies 1 and 10 when the mold is closed. act.

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 the mold bodies 1 and 10 under pressure as shown by arrow A, and the mold is molded. After that, the above-mentioned pressure is released, the upper mold main body 10 is slid laterally to open the mold, and the molded article is taken out.

As described above, this mold can perform suction dehydration from both the bottom side and the top side of the molding recess 8, so when manufacturing a large ceramic plate using a large amount of wet composition 13,
The molding can be carried out in a short time, and suction and dehydration can be performed uniformly throughout the body, resulting in the formation of a homogeneous molded body.

Note that in the above mold, the upper mold body 1o is also equipped with the porous elastic body 5 with continuous pores, but the upper mold body 10 is not necessarily equipped with the porous elastic body 5 with continuous pores as described above. It is not necessary to do this, and the molding recess 8 may be covered with a rubber plate or the like.

In the present invention, suction and dehydration of the wet composition pressure-cast into the molding recess is performed through the continuous pores of the porous elastic body, and usually the continuous pores are used as in the mold shown in the drawing. Vacuum suction is applied from the outer peripheral surface of the attached porous elastic body 5 to perform suction dehydration. In this case, even if the suction dehydration is performed at a certain degree of vacuum, the suction force is appropriately relaxed through the continuous pores in the porous elastic body 5 with continuous pores, and the wet composition 13 in the molding recess 8 is added to. Therefore, the molding of the wet composition 13 is not adversely affected by the suction force during suction dehydration.

In particular, when producing ceramic plates by the method of the present invention, it is effective for producing large ceramic plates with three-dimensional patterns formed on their surfaces. That is, according to the above method, since the molding is performed using a wet composition, the distribution of the powder becomes uniform, and since it is performed by pressure casting, it can be performed quickly. Furthermore, since suction dehydration is performed, it is possible to quickly remove water, and therefore it is possible to adequately handle large ceramic plates using a large amount of wet composition. Moreover, since it is performed by wet molding, by forming an uneven pattern for three-dimensional pattern transfer on the bottom of the molding recess, it is possible to easily and precisely transfer and form a three-dimensional pattern on the surface of the large ceramic plate. Become.

Note that the molded article obtained as described above can be demolded by suctioning with a suction cup or the like. Then, the demolded molded body is subjected to conventionally known drying and firing treatments corresponding to the physical properties of the raw material composition.

The ceramic plate obtained in this way has a uniform distribution of powder, does not have cracks or cracks, and has extremely high strength.
The surface becomes dense.

〔Effect of the invention〕

As described above, the present invention uses a porous elastic body with continuous pores having molding recesses in place of the water-permeable gypsum dish-shaped mold in the conventional wet method, and manufactures tiles in the form of slurry in the molding recesses. In order to manufacture molded products by pressurizing the raw material composition and then dehydrating it by suction, it is possible to achieve a uniform powder distribution using the wet method, while also shortening the draining time.
It is possible to efficiently produce ceramic plates that have high strength and do not break or crack. In particular, according to the present invention, it is possible to manufacture large ceramic plates having an uneven pattern on the surface extremely efficiently and without increasing the size of the equipment as in the dry method, which has extremely practical effects. big. Moreover,
With the mold according to the invention, in addition to the above properties,
Furthermore, it is possible to produce a large-sized ceramic plate with a homogeneous structure with good efficiency.

Next, examples will be described in detail.

〔Example〕

First, a mold as shown in FIG. 1 was prepared as a mold. Next, 40 parts by weight of clay raw material.

A ceramic raw material composition 13 consisting of 55 parts by weight of felsic powder preservative and 5 parts by weight of talc and having a moisture content of about 20% is transferred from the tank 11 into the molding recess 8 of the lower mold body 1. at a pressure of 20 kg/cI11.

Next, the composition 13 was drained for 5 minutes by vacuum suction, and the obtained molded body was demolded. After drying this molded body at 300 to 500°C for 1 to 3 hours, it was fired in a firing furnace at a temperature of 1000°C or higher. In this case, the drying and firing were carried out by pre-drying and pre-heating so as not to cause cracks in the compact, followed by main drying and heating. The tiles obtained in this way had large dimensions of 300 x 300 x 10 mm, were beautiful with three-dimensional patterns formed on the surface, and were extremely strong with no cracks or cracks. .

In the above embodiment, the mold shown in FIG. 1 is used, but the mold shown in FIG. 2 may be used instead. The mold shown in FIG. 2 has an inner container 1a inside a lower mold body l and an upper mold body 10.

A large number of small holes 1 are provided in the inner container 1a, 1.0a.
b, 10b are provided, the porous elastic body 5 is accommodated in the inner containers 1a, 10a, and the contents 2W1a, 10a and the mold body 1 are provided.
．． Vacuum suction is performed from the gap 6 between the porous elastic body 5 and the entire bottom surface of the porous elastic body 5, so that the draining time can be significantly shortened. .

In the above example, a large tile with an uneven pattern formed on the surface is manufactured, but the above example also applies to small flat tiles (approximately 10 square meters and 11 square meters) 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 drawings]

FIG. 1 is a sectional view of one example of a mold used in the present invention, and FIG. 2 is a sectional view of another example. 1... Lower mold body 2... Bottom plate 3... Side plate 5.
...Porous elastic body with continuous pores 6...Void 7...
Crosspiece 8...Molding recess 10...Upper mold body 11.
...Wet composition tank 13...Wet composition 14.
...Vacuum suction pipe patent applicant Tokai Rubber Industries Co., Ltd. Figure 2

Claims (6)

[Claims] (1) Place a corresponding upper mold body on a lower mold body comprising a porous elastic body with continuous pores having a molding recess, cover the molding recess, and in this state insert the mold into the molding recess. A slurry-like raw material composition is pressure cast, the raw material composition is suction-dehydrated through the continuous pores of the porous elastic body with continuous pores, and the obtained molded product is demolded and subjected to a firing process. A method for manufacturing ceramic plates characterized by forming them into ceramic plates. (2) The method for manufacturing a ceramic plate according to claim 1, wherein a concave-convex pattern for transferring the concave-convex pattern is formed on the bottom surface of the molding recess. (3) The method for manufacturing a ceramic plate according to claim 1 or 2, wherein the porous elastic body with continuous pores is composed of a sponge-like body made of rubber or synthetic resin. (4) The moisture content of the slurry-like raw material composition is 20 to 25
A method for manufacturing a ceramic plate according to any one of claims 1 to 3, wherein the content is set to % by weight. (5) Pressure casting of slurry-like raw material composition
A method for manufacturing a ceramic plate according to any one of claims 1 to 4, which is carried out at a pressure of kg/cm^2. (6) A lower mold body having a U-shaped cross section, and a U-shaped cross section that is detachably attached to the lower mold body with the U-shaped opening aligned with the U-shaped opening of the lower mold body. an upper mold body; first and second porous elastic bodies with continuous pores accommodated in the upper mold body and the lower mold body, respectively, with a gap provided between the bottom surface of the mold body; A molding recess formed on the surface of the second porous elastic body with continuous pores, and a raw material casting means for pressure-casting a slurry-like raw material composition into the molding recess when the upper mold body is installed. and a mold comprising suction means for vacuuming the gap between the mold body and the porous elastic body with continuous pores in both mold bodies.