FR2798378A1 - COMPOSITION FOR MOLDING - Google Patents

Abstract

This molding composition comprises from 0 to 85% by weight of a refractory aggregate, from 2 to 30% by weight of a hydraulic binder, from 0 to 20% by weight of a fluidizing agent, from 10 to 70% by weight of a flux, and from 5 to 35% by weight of water. Application in the field of the ceramic industry.

Description

The present invention relates to a composition for molding in the

  field of the ceramic industry.

  Currently, we are witnessing a craze for the molding of subjects or pieces present in particular in museums. However, in the ceramic industry, the molding of large parts or complex shapes requires the use of several molds and the implementation of connection techniques between the different molded parts: this leads to many manipulations that can be detrimental to the quality of the molded object and therefore a significant cost which could make the molding of certain parts uninteresting from an economic point of view. It is recalled that the materials from the traditional ceramic industry are called earthenware, stoneware, sanitary or collective porcelain, ceramic according to their composition and / or their use, but are all clay-based

  and are molded in absorbent molds and / or by pressing.

  Also, one of the aims of the present invention is to provide a composition for molding, which makes it possible to carry out the molding of any object at one time.

  whatever the dimensions and / or the complexity thereof.

  Another object is to provide such a composition which can be used in

  cooperation with all types of non-absorbent molds, flexible or rigid.

  These aims, as well as others which will appear subsequently, are achieved by a molding composition which is characterized, according to the present invention, by the fact that it comprises from 0 to 85% by weight of a refractory aggregate, from 2 to 30% by weight of a hydraulic binder, from 0 to 20% by weight of a fluidizing agent,

  to 70% by weight of a flux, and from 5 to 35% by weight of water.

  Advantageously, this composition also comprises from 0 to 40% by weight

  of a metallic filler, and at most 2% of one or more surfactants.

  Preferably, the refractory aggregates are chosen from calcined clays such as chamottes or molochites, pure alumina, silica under

form of quartz or cristobalite.

  Advantageously, the hydraulic binder is chosen from cements and

plasters.

  Preferably, the fondant is chosen from sodium feldspars or

  soda-potassium, nepheline syenite, cullet, crushed glass.

  Advantageously, the surfactant is chosen from wetting agents,

debullants, deflocculants.

  The description which follows and which is in no way limiting, per -

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  will enable those skilled in the art to be better able to redo the present invention and

  to better understand the benefits.

  To produce a composition according to the present invention, the various constituents are mixed dry, then water is added so that the water content of the composition is at most 35%. But we can also mix the different constituents by diluting them in water with stirring:

  introduce them, for example, in descending order of difficulty of dilution.

  The examples below relate to a certain number of compositions which

  were carried out according to the present invention.

Example 1

  The compositions below were produced to obtain different earthenware: Composition (% by weight) F1 F2 F3 F4 F5 Binder: plaster 20 14 12 11.6 11.7 - cement with 70% alumina 3, 9 Refractories: molochite or chamotte <0.150 mm 13 16 - molochite or chamotte <0.5 mm 18 18.5 15.6 - silica <0.150 mm 14 17 19 18.6 15.6 Mineral thinning agent: 0 0 4.8 4 , 6 7.8 Fondant: - Sinter with low melting point <0.08 mm 21 Sodicopotassium feldspar <0.08mm 23 25 21.6 23.6 - Talc ___ 2.3 Surfactants: - wetting agent 0 0 0.4 0 , 4 0.4 - boiling 0 0 0.4 0.4 0.4 Water 32 30 20.4 22 21 Cooking (OC) 800 to 1100 1140 1140 1140 1000 These different compositions made it possible to obtain objects by pouring by gravity in molds, which were baked at the above temperatures after demolding.

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Example 2:

  The compositions below were produced for obtaining colored earthenware: Composition (% by weight) FC1 FC2 FC3 FC4 Binder: - plaster 14 11, 2 14 14 Refractories - molochite or chamotte <0.150 mm 20 - molochite or chamotte <0.5 mm 11 10 7 - silica <0.150 mm 1 1 10 8 18 Mineral thinning agent: 0 4.5 0 0 Fondant: - Sinter with low melting point <0.08 mm 23 37 Soda-potassium feldspar <0.8 mm 18, 5 - Talc 2.5 - White glass 23 Surfactants - wetting agent 0 0.4 0 0.4 - boiling 0 0.4 0 0.4 Metal: iron filings 14.5 15 7.5 - copper filings 0, 1 to 1 Water 26.5 23 26.5 28 Cooking (OC) 800 to 800 to 800 1 140

1,000 1,000

  These various compositions made it possible to obtain objects by gravity casting in molds, which were baked at the above temperatures after demolding.

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Example 3:

  The following compositions were produced for obtaining white sandstone: Composition (% by weight) G1 G2 G3 Binder: - 70% alumina cement 1.5 4 - white cement 6 4 - 80% cement alumina 15 Refractories: molochite or chamotte <0.150 mm 28.5 18 - silica <0.150 mm 21 19 crushed porcelain shard <0.150 mm 68.85 Mineral fluidizer 0 0 0 Fondant: - Talc 2 3.5 - Sodium feldspar < 0.08 mm 12 20 Surfactants: wetting agent 0 0 0 - boiling 0 0 0 - deflocculant 0.15 Water 29 24.5 23 Cooking (OC) 1280 1280 1280 These various compositions made it possible to obtain objects by pouring by gravity in molds, which were baked at the above temperatures after

demoulding.

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Example 4:

  The composition below was produced to obtain a chamotte sandstone: Composition (% by weight) GC1 Binder: - cement with 70% alumina 3, 5 Refractories: - molochite or chamotte <0.5 mm 38.06 -silica <0.150 mm 8 Mineral fluidizer 7.6 Fondant: - Soda-potassium feldspar <0.08 mm 19 Surfactants: - wetting agent 0.4 - boiling 0.4 - deflocculant 0.04 Water 23 Cooking (OC) 1,280 This composition made it possible to obtain objects by gravity casting

  in molds, which were cooked at the above temperature.

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Example 5:

  The composition below was produced to obtain a vitreous or sanitary porcelain: Composition (% by weight) Vi Binder: -cement with 70% alumina 3.5 Refractories: - molochite or chamotte <0.150 mm 21 - silica <0.150 mm 21 Mineral fluidizer O Fondant: - Soda-potassium feldspar <0.08 mm 24.5 Surfactants: - wetting agent 0 - boiling 0 - deflocculant 0 Water 30 Cooking (C) 1 250 to 1 300 This composition allowed to obtain objects by gravity casting

  in molds, which were baked at the above temperature after demolding.

o10

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  Example 6: The following compositions were produced to obtain a chamotte stoneware with a view to pouring it under vibration: Composition (% by weight) GC 1 GC 2 GC 3 Binder: - cement with 70% alumina 3.9 3.9 3.8 Refractories: chamotte with 40% alumina <0.7 mm 42.16 - chamotte with 40% alumina from 0.1 to 0.5 mm 14.8 - chamotte with 40% alumina from 0.2 to 0.5 mm 14.8 20.4 chamotte with 40% alumina from 0.1 to 0.4 mm 13.9 15.3 - chamotte with 40% alumina <0.1 mm 6.8 - silica <0.150 mm 8 9 8.61 Mineral fluidizer 8.5 8.7 8.5 Fondant: - Soda-potassium feldspar <0.08 mm 22 21.25 Nepheline syenitic <0.08 mm 22, 06 _ Surfactants: - wetting agent 0.4 0.4 0.4 - boiling 0.4 0.4 0.4 - deflocculant 0.04 _ 0.04 0.04 Water 14.6 12 14.5 Cooking (C) 1,280 1,280 1,280

  The objects obtained were removed from the mold and then baked at the above temperatures.

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Example 7:

  The following compositions have been made to obtain a sandstone

  white for casting under vibration.

  Composition (% by weight) GB1 GB2 GB3 GB4 GB5 I GB6 Binder: - cement with 70% alumina 4.3 4.2 4.3 4 4.1 4.1 Refractories: - molochite <0.053 mm 29 21, 7 13, 4 - molochite <0.5 mm 30 21.1 22.3 - alumina <0.08 mm 25.8 24.9 33, 7 33.8 34.7 33.18 Fondant:

- Feldspar sodico-

  potassium <0.08 mm 17.2 16.6 12.7 12.9 13.2 12.62 - crushed white glass <0.150 mm 7.9 Mineralizing agent 8.6 8.3 12.7 8.1 8, 2 7.9 Surfactants: wetting agent 0.45 0.4 0.4 0.4 0.4 0.4 - boiling 0.45 0.4 0.4 0.4 0.4 0.4 0.4 deflocculant 0.2 0.2 0.2 0.2 0.2 0.2 Water 13 16 14.5 18.5 16.5 20 Cooking (C) 1290 1290 1290 1290 1290 1290

  The objects obtained were removed from the mold and then baked at the above temperatures.

  After demoulding of the objects obtained from the compositions according to these various examples, these still obtained parts must be dried in order to

  avoid their explosion when the temperature rises, during the cooking phase.

  Before being enamelled, the parts are, if necessary, engobed by spraying: this makes it possible to hide surface irregularities notably due

  with chamotte seeds and the color of the shard if necessary.

  Before being enamelled, they can also be biscuit that is to say

  fired a first time in order to obtain a better quality of enamel.

  The products obtained from the compositions according to the present invention offer an acceleration of the shaping and allow a longer lifespan

  mussels as well as an energy saving by making their drying unnecessary.

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Claims (6)

  1. - Composition for molding, characterized in that it comprises of   0 to 85% by weight of a refractory aggregate, from 2 to 30% by weight of a hy-   hydraulic, from 0 to 20% by weight of a fluidizing agent, from 10 to 70% by weight   a flux, and from 5 to 35% by weight of water.   2. - Composition according to claim 1, characterized in that it also comprises from 0 to 40% by weight of a metallic filler, and at most 2% of a or more surfactants.   3. - Composition according to claim 1, characterized in that the   refractory aggregates are chosen from calcined clays, pure alumina, si-   lice in the form of quartz or cristobalite.   4. - Composition according to claim 1, characterized in that the binder   hydraulic is chosen from cements and plasters.   5. - Composition according to claim 1, characterized in that the fungus   dant is chosen from sodium or soda-potassium feldspars, syenites   nepheline, cullet, crushed glass.   6.- Composition according to claim 2, characterized in that the agent   surfactant is chosen from wetting agents, boiling agents, deflocculants.