JP2577667B2 - Ceramic mold - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gypsum mold used for casting ceramic articles such as toilet bowls.

[0002]

2. Description of the Related Art Generally, in ceramic products such as toilets,
The slurry, which is a suspension of raw materials such as feldspar, frog-eyed clay (ball clay), sericite, kaolin, sierven, and silica sand, is poured into a casting mold such as a gypsum mold or a resin mold to grow the meat. The forming base is formed. The formed base is dried, glazed and fired to be a product. The gypsum mold is obtained by mixing gypsum powder and water to form a slurry, injecting into a mold, and hydrating and hardening the same. The mechanism of hydration hardening is that, when calcined gypsum is hydrated, needle-like crystals are intersected and formed, which solidifies to form a mold.

[0003]

However, when a ceramic product is cast and molded using a gypsum mold, the diffusion speed of water of the gypsum itself is low in a complicated or narrow place, and the molding base is not good. There was the disadvantage of stickiness. Therefore, conventionally, powder of talc (talc) or calcium carbonate was dissolved in water and applied as a mold release agent to the molding surface of the gypsum mold in advance. However, when such a mold release agent is applied, there is a disadvantage that the surface of the molding base is roughened, and the quality of the product is impaired.

[0004]

DISCLOSURE OF THE INVENTION The present invention has been improved and eliminated in view of the above-mentioned drawbacks, and does not provide a mold in which a mold release agent is impregnated inside gypsum needle crystals. It is assumed that.

[0005] In Thus, the means for the present invention is employed to solve the problem, the powder 70 to 95 wt% gypsum, release agent powder such as calcium carbonate or talc 5~30wt
% Of water is 60 to 9
A mold formed by solidifying a material obtained by mixing and stirring 0 wt% , wherein the mold release agent is impregnated in a powder state between needle-like crystals of gypsum.

[0006]

According to the present invention, in forming a gypsum mold,
A release agent such as calcium carbonate or talc is mixed together with the gypsum powder, and mixed and stirred with water . Mixing ratio of stone
70-95 wt% of plaster powder, calcium carbonate or talc
Powder release agent such as 5% to 30% by weight of mixed powder raw material
Then, 60 to 90% by weight of water is added.
In addition, the outside division means that the weight of the mixed powder raw material is 100.
The weight of the newly added water
Say. As a result, the gypsum undergoes hydration hardening, and the mold release agent is impregnated between the needle crystals.
Therefore, when the ceramic body is cast and molded using the gypsum molding die, even if the molding surface is worn, the powder of the release agent always oozes out on the molding surface, and the inlaid slurry is formed. It doesn't stick to the surface.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction of the present invention will be described below with reference to the embodiments shown in the drawings.

FIG. 1 is a longitudinal sectional view of a molding die 1 according to one embodiment of the present invention. As shown in FIG. 1, in this molding die 1, a gap in which needle-like crystals 2 of gypsum intersect with each other is impregnated with a release agent 3 such as calcium carbonate or talc (talc) in a powder state. . The method of impregnation is only required to mix and stir gypsum powder, the powder of the release agent 3 of calcium carbonate or talc, and water to form a suspension, inject the suspension into a matrix, and solidify it. . That is, when forming a normal gypsum mold, it is only necessary to add the release agent 3 in excess, and a special manufacturing method is not required.

The mixing ratio of gypsum powder, release agent 3 such as calcium carbonate or talc, and water may be in the following range. First, gypsum powder and a release agent 3 such as calcium carbonate or talc are added and mixed at a ratio of 5 to 30 wt% of the gypsum powder to 70 to 95 wt% of the gypsum powder. , And water is added in a range of 60 to 90 wt% on an external basis and mixed and stirred. The reason why the mixing ratio of the release agent 3 is limited to 5 to 30 wt% in the mixing ratio of the gypsum powder and the release agent 3 is that when the mixing ratio is less than 5 wt%, the ratio of the release agent 3 to the whole becomes small. This is because the effect as a release agent cannot be exhibited. In addition, the ratio of the release agent 3 is 30 wt.
On the other hand, if the ratio exceeds%, the ratio of gypsum to the whole becomes small, and the strength of the mold itself when the mold is formed becomes weak. In the mixing ratio, the reason why the water ratio is limited to the above range is that if the water ratio is lower than 60 wt%, the fluidity is deteriorated, and a mold having a complicated shape is difficult to form.
If the amount exceeds 0 wt%, the gypsum hardly hardens and the strength of the mold becomes insufficient. In the case of the molding die 1 molded at such a mixing ratio, the gap in which the gypsum needle-like crystals 2 intersect with each other is impregnated with the release agent 3 such as calcium carbonate or talc in a powder state, The release agent 3 is present as a powder in a state of exuding on the molding surface. Therefore, when the slurry is cast in the molding die 1,
It has good mold release from the sedimented slurry, and does not damage the molding base or deteriorate the surface properties of the molding base even in a portion having a complicated shape. Also, as the number of times of casting of the molding base increases, the molding surface of the molding die 1 becomes worn. Even in such a case, the release agent 3 keeps the powder between the needle-like crystals 2 of the gypsum. , So that it always appears on the worn surface, and has the effect of always functioning sufficiently as the release agent 3.

[0010]

As described above, in the gypsum mold of the present invention, a mold release agent such as calcium carbonate or talc is impregnated with a powdery bear between needle-like crystals intersecting gypsum. Therefore, a powder of a release agent such as calcium carbonate or talc can always be present on the molding surface of the molding die made of gypsum. Therefore, when the ceramic body is cast using the gypsum mold, the mold releasability of the mold and the mold body is good. Moreover, with the increase in the number of times of casting, even if the molding surface is worn, a state in which the powder of the release agent oozes out on the molding surface is always obtained, so that the inked sludge sticks to the molding surface. Absent.

[Brief description of the drawings]

FIG. 1 is a partial longitudinal sectional view showing the internal structure of a molding die according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Mold 2 ... Needle crystal 3 ... Release agent

Claims (1)

(57) [Claims] From 1 claims] and powder 70 to 95 wt% of the gypsum, a release agent 5-30 wt% of the powder such as calcium carbonate or talc
60-90wt% water based on the mixed powder raw material
A mold formed by solidifying a material obtained by mixing and stirring the above, wherein the mold release agent is impregnated in a powder state between needle-like crystals of gypsum.