JPS59136209A - Die for molding foundation of ceramic - Google Patents

Abstract

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

Description

[Detailed description of the invention] This invention relates to a mold for molding ceramic base material.

Conventionally, a plaster mold is usually used as a mold for molding a ceramic base. This is because the plaster mold gives plasticity to the ceramic slurry or clay and dehydrates it! It can be made into a W shape, has self-hardening properties in a short time when calcined plaster and water are mixed, and expands slightly during self-hardening to create a precise model. This is because it has excellent advantages as a mold material, such as water absorption and good mold releasability. However, on the other hand, the mold is damaged quickly due to surface abrasion because it is soluble in water, and the decomposition temperature of hydrated self-hardening hydrated gypsum is approximately 39°C, and the mold is forced to dry by heating. If this is not done with extreme care, the mold may be damaged by compositional changes, thermal shock, mechanical impact strength,
Due to low mechanical strength such as tensile breaking strength, bending strength, and abrasion resistance, there are drawbacks such as breakage during work and transportation, and severe wear due to friction with the ceramic base, so the number of times the plaster mold can be used is limited. β has a high water absorption rate of the used type.
Gypsum molds using type gypsum can only be used up to about 100 times, and even those using α-type gypsum, which requires less mixed equipment to make the mold and has a lower water absorption rate, can only be used a few hundred times. . Therefore, synthetic resin porous bodies, inorganic powder sintered bodies, etc. are being studied as mold materials to replace plaster molds, and improvements have been made in terms of reduced surface wear due to water resistance, heat resistance, thermal shock resistance, and mechanical strength. They do not have the excellent properties of plaster molds, such as the lack of self-hardening properties, the complicated mold manufacturing process, poor mold releasability, and the difficulty of manufacturing complex and large molds.

This poses a major obstacle to the mechanization of small quantities and processes for large-sized castings such as sanitary ware, and there is a demand for the development of a mold for molding ceramic bases that has the same advantages as the plaster mold described above and does not have its drawbacks. has been done.

In view of the current situation, the present invention has been developed to provide a mold that has properties similar to those of plaster molds, and has good surface abrasion resistance, heat resistance,
This mold was developed for the purpose of molding ceramic bases, which has high thermal shock resistance, excellent mechanical strength, and is easy to manufacture even complex and large-sized molds.The main material is wollastonite powder, and it is made of cement, aggregate, and water. It is characterized by the mold material being molded and hardened by adding and kneading the mold material.

The wollastonite powder used as the main material in the present invention is used to give the mold itself a porosity and pore shape similar to that of plaster due to the crystal shape and particle shape of wollastonite, and its particle size is similar to that of molded ceramics. 20 in consideration of the surface roughness of the substrate.
It is common to use powder that has been pulverized to the extent that 80% or more passes through a 0-mesh sieve, but more desirable results can be obtained by using one that has been pulverized to the extent that 80% or more can pass through a 3-5 mesh sieve. In order to make the porosity and pore shape of the mold equal to those of conventional plaster molds, it is necessary to have at least 50% by weight, preferably 60% or more.

On the other hand, aggregates to be added to wollastonite powder, which is the main material, together with cement powder, which will be described later, are not particularly limited, such as perlite, calcium carbonate fine grains, etc. in addition to silica sand, but silica sand, which is inexpensive and easily available, especially 6 It is common to use No. silica sand, and in this case, if the amount of sand used exceeds 20%, it will affect the releasability of the ceramic molded body from the used mold, and the
If it is less than 70%, it will affect the molding, so it is preferably 70~
It should be about 20%. In addition, it is used to increase the strength of the above-mentioned 7F, and since the development of color strength using ordinary Portland cement is considerably delayed, it can be cured in a short time to ensure sufficient strength. It is preferable to use ultra-fast hardening cement, and when kneading wollastonite powder, cement, and aggregate to form a slurry-like mold material with good moldability, the moisture content of the wollastonite powder, cement, and aggregate should be reduced. The number will be approximately 35, compared to the Ioo Jushabu. In addition, if necessary, adding about 2 parts of water-soluble synthetic resin such as water-soluble epoxy resin to 100 parts by weight of powder metal will further increase the strength of the mold material and make the abrasion resistance 30% higher than that of plaster mold. ˜jO times, and the intensity of the song is about 200 −, which is more preferable. Further, if a water reducing agent for cement and an antifoaming agent are added to the needle part of the mold having a total powder content of 700/-2 times, the fluidity of the kneaded mold material will be improved. In addition,
When a water-soluble epoxy resin is blended, a polyamide curing agent is used as a curing agent for the water-soluble epoxy resin.
Mix about 4 layers.

The product constructed in this way is molded using a slurry-like mold material made by stirring and kneading the main material, which is Masuko Iume wollastonite powder, to which aggregates such as ultra-fast hardening cement and silica sand are added together with hypersensitive water. Because it is a hardened material, it has approximately 20 times more wear resistance than conventional plaster as the main material, and has greater bending strength, and has excellent heat resistance, water resistance, and other mechanical strength. It has many superior properties, can be pressure cast, can withstand repeated use over 100 times, completely eliminates the drawbacks of plaster molds, and is mainly made of wollastonite powder. As a result, the porosity and pore shape of the mold itself are almost the same as those of conventional plaster molds, and it has most of the features of plaster molds, such as good plasticity of the ceramic base and good dehydration and mold release properties. . Therefore, in order to manufacture such molds for molding ceramic bases, for example, a water-soluble epoxy resin and a hardening agent are emulsified and dispersed in water using a high-speed stirrer, and this emulsified suspension is placed in a concrete stirrer to reduce the amount of water used for cement. A predetermined amount of silica sand, wollastonite powder, and ultra-fast hardening cement are added while kneading, and a slurry-like mold material is degassed under vacuum after kneading. It is a good idea to cast the mold into a case mold that has been treated with the above-mentioned methods, develop early strength within 7 to 3 hours after casting, and then remove the mold from the case mold. Mass production is also easy0 Example: 35 parts of water, water-soluble epoxy resin (product name: Niadeka Epoxy Resin') 2P-'1100> 2 parts (overlapping parts, same hereinafter) and curing agent (product name: ADEKA Epoxy Hardener) E
R-, 20 J)/part and emulsified and dispersed using a high-speed stirrer, and put this emulsified suspension into a concrete mixer.
Add and mix No. 2 silica sand IO part as aggregate, 10 parts of wollastonite powder passed through 32J mesh sieve, 2 parts of water reducing agent for concrete (trade name: Positive Pressure Mighty 15O) and a small amount of setting regulator, and then mix. 30 parts of cement (trade name: Onoda Jet Cement) was added, kneaded and vacuum defoamed, and the slurry-like mold material obtained by kneading was cast into a case mold pre-applied with a concrete mold release agent for 2 hours. After the cement hardened and early strength was developed, the used mold was removed from the case mold, cured, and dried to be used as a mold for molding large sanitary ware. When the mold thus prepared was used, the deposition speed of the sanitary ware base was twice as fast when the mold was pressure-molded at θj1 and when the right part of the mold was molded without pressure. In addition, the durability of the plaster mold of the same shape was 100 times, whereas the one of the present invention had a durability of 100 times.

It withstood the same level of use.

As is clear from the MU description, the present invention uses wollastonite powder as the main material, so it has the same characteristics as a plaster mold, and has better abrasion resistance, heat resistance, thermal shock resistance, and better resistance than a plaster mold. It has various advantages such as high mechanical strength, good mold releasability, easy production of complex and large items, and low production cost, and solves the problems of conventional molds for molding ceramic bases. This is an extremely important contribution to the development of the industry.

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Claims (1)

[Claims] A mold for molding a ceramic base, characterized in that it is made by molding and hardening a mold material made of wollastonite powder as a main material and mixed with cement, aggregate and water.