JPH0688849B2 - Method for producing ceramic foam - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for manufacturing a ceramic foam. More specifically, it relates to a method for producing a ceramic foam having a skin layer of glaze on the surface.

[Conventional technology]

The ceramic foam is produced, for example, by heating a ceramic foamable composition obtained by mixing a foaming agent in powder such as volcanic ash or glass with a foaming agent to a temperature for foaming, as described in JP-A-60-221371. There is. This ceramic foam is attracting attention as a suitable building material because it is lightweight and highly durable.

When using ceramic foam as a building material,
Generally, it is desirable to apply glaze to the surface of the ceramic foam to improve its appearance and durability.

A conventional method for applying glaze makeup to ceramic foam is to cool the ceramic foam produced by heating and foaming, then apply glaze on the surface, heat it again, and bake the glaze onto the ceramic foam. It has been known.

[Problems to be solved by the invention]

However, in the above method, since heating for foaming and heating for baking the glaze are performed in two stages, the loss of fuel is large and not only uneconomical, but also the manufacturing process is complicated. there were.

[Means for solving problems]

The present invention has been made to solve the above problems,
The gist is to put the granulated non-foaming glazes on the granulated ceramic foamable composition, then heat to the foaming temperature to foam the ceramic foamable composition into a ceramic foam and to form the glaze. It is a method for producing a ceramic foam, which comprises baking the material and then cooling it.

[Action]

When the granulated ceramic foamable composition is heated for foaming, a good ceramic foam having a uniform cell diameter can be obtained.
Therefore, the glazes on the ceramic foamable composition are also melted to form a uniform skin layer. In addition, the granulated glaze has a good compatibility with the ceramic foamable composition and forms an excellent skin layer when melted.

The ceramic foamable composition used in the present invention is mainly composed of volcanic rock such as anti-firestone, volcanic ash such as shirasu, feldspar, clay, glass powder, etc., and if necessary, foaming temperature adjustment such as soda ash. And a foaming agent such as silicon carbide are added, and the ceramic composition has a property of foaming when heated.

In the present invention, the ceramic foamable composition used is granulated. As the granulation method, various granulation methods such as a roll granulation method, an extrusion granulation method, and a rotary disc type granulation method can be used.

The reason for using the granulated product is that if a ceramic foamable composition of a powder that is not a granulated product is used, the unevenness of the surface of the ceramic foam after foaming becomes large, and it is difficult to obtain a good foam.

The size of the granulated product is not particularly limited, but the diameter is 0.5 mm to 3
The range of mm is preferable.

As the non-foaming glaze used in the present invention, those normally used for ceramics, roof tiles, enamels, etc. are used as they are, but particularly in the present invention, at the foaming temperature of the ceramic foaming composition or lower. It is preferable to use a material that softens and melts. Furthermore, the glazes of the present invention, in addition to the above glazes, volcanic rocks that melt below the foaming temperature of the ceramic foamable composition, inorganic materials such as volcanic ash, or pigments added to these, have the same effects as glazes. It includes all eggplants. For example, it is possible to use a ceramic foamable composition from which a foaming agent has been removed, to which a softening temperature lowering agent such as sodium carbonate or borax has been added, or to which a pigment has been added. The softening temperature of the glaze is particularly preferably 100 ° C. to 300 ° C. lower than the foaming temperature of the ceramic foamable composition. And, as a preferable one of the glazes used in the present invention, the volume expansion coefficient is substantially the same as that of the ceramic foam, and as such, the volume expansion coefficient is 130 × 10 ⁻⁷ to 250 × 10 ⁻⁷ . Those are preferable.

In the present invention, glazes are granulated and used. The reason for using the granulated product is that if the glaze is used as powder, cracks are likely to occur when the glaze is melt-baked.

As the granulation method of glazes, the same method as in the ceramic foamable composition can be used. At this time, it is preferable to add a small amount of clay such as bentonite, frog clay, and clay, for example, 1 to 10% because granulation becomes easy.

There is no particular limitation on the size of the glaze granules, but the diameter is 0.
It is preferably 2 mm to 2 mm.

Next, embodiments will be described with reference to the drawings.

In the figure, 1 is a ceramic foam manufacturing apparatus. This ceramic foam manufacturing apparatus 1 has a conveyor 2.

The conveyor 2 is made of a fine mesh made of heat-resistant metal such as stainless steel. When the conveyor 2 travels on the lower side, the release agent 4 is applied to the surface by the application device 3. As the release agent 4, aluminum oxide powder, aluminum hydroxide powder, silica sand powder, calcium carbonate powder, clay powder or the like is used.

A main raw material hopper 5 and a glaze hopper 7 are arranged above the conveyor 2, and the ceramic foamable composition 6 granulated from the hopper 5 and the granulated glaze 8 are sequentially dropped from the hopper 7. , And each of them is supplied on the conveyor 2 in a substantially uniform thickness.

If necessary, a mold plate coated with a release agent can be placed on this. Alternatively, a release paper may be placed, and a template may be placed on the release paper to apply pressure.

Next, the conveyor 2 sequentially passes through a preheating furnace 9, a heating furnace 10, and a slow cooling furnace 11.

Ceramic foamable composition 6 while passing through heating furnace 10
Is heated to the foaming temperature. Then, the glazes 8 are softened and melted, and the ceramic foamable composition 6 is softened and melted and foamed to form a ceramic foam having a glaze layer on the surface.

Next, it enters the slow cooling furnace 11, is slowly cooled, and then goes out of the furnace.

The granulated ceramic foamable composition 6 becomes a good ceramic foam having a uniform bubble diameter when foamed, as compared with a non-granulated ceramic foamable composition 6.

When the glaze is melt-baked, cracks may occur in the layer, but in the present invention, since the glaze is granulated, the occurrence of cracks is prevented, and the granulated ceramic foamable composition is also present. Combined with the fact that a uniform ceramic foam is obtained, the glazes are melted and baked uniformly, and a beautiful surface layer of glazes is formed.

Further, at this time, if the template 12 is placed on the top, a good product with the pattern of the template 12 is completed.

〔The invention's effect〕

This invention, after placing the non-foaming glaze on the ceramic foamable composition, since it is heated to the foaming temperature, the heating step of the foaming of the ceramic foamable composition and melting of the glaze becomes one step, It is both simple and economical. Further, since the granulated ceramic foamable composition and the granulated glaze are used, it is possible to obtain a good ceramic foam having a uniform cell diameter and to form a uniform and beautiful skin layer on the surface thereof. You can

The ceramic foam obtained by the present invention can be suitably used as a building material such as an outer wall material of a house, a floor material, a roof material, or a heat insulating material.

Example 1 58 parts by weight of anti-firestone powder, 25 parts by weight of glass powder, 10 parts by weight of bentonite, 5 parts by weight of soda powder, and urexide 2
A ceramic foamable composition consisting of 1 part by weight and 0.3 parts by weight of silicon carbide powder is uniformly mixed, and 15 parts by weight of water is added to this and kneaded well, and granulated by an extrusion granulator having a number of 1 mm in diameter. After that, it was thoroughly dried to produce a granulated product of the ceramic foamable composition.

In addition, 8 parts by weight of bentonite was added to 100 parts by weight of white glaze (XT-275N manufactured by Nippon Frit Co., Ltd., softening temperature of 657 ° C, volume expansion coefficient of 195 x 10 ^-7 ) and thoroughly mixed, and then 20 parts of water Parts were added and kneaded well, and granulated with the same extrusion-type granulator used for granulating the ceramic expandable composition.
Then, it was sufficiently dried to obtain a granule of glaze.

Granulated ceramic foamable composition 6 as main raw material hopper 5
And the granulated glaze 8 was put into the glaze hopper 7.

On the conveyor 2, the ceramic foamable composition 6 was uniformly supplied from the main raw material hopper 5 to a thickness of about 30 mm, and then the glaze hopper 7 to the glaze 8 were placed thereon to a thickness of about 5 mm. A silicon carbide template 12 was placed thereon. On the surface of the template 12, a release agent having a small amount of bentonite added to alumina powder to improve adhesion to the template 12 was applied.

These were introduced from a preheating furnace 9 to a heating furnace 10, where they were heated to 970 ° C. to soften and melt the glazes 8 and at the same time soften and melt the ceramic foamable composition 6 to foam. At this time,
Since the surface of the ceramic foam is pressed by the template 12, it has the shape of the template 12. After that, the ceramic foam is gradually cooled in the annealing furnace 11 and cooled to about 100 ° C.,
When you reach the exit and remove the template 12 here, the template 12
A glaze-decorated ceramic foam patterned with was obtained.

The resulting ceramic foam has a thickness of approximately 43 mm and a specific gravity of 0.63.
And had a beautiful skin layer whose surface was covered with a layer of white glaze.

Example 2 Shirasu powder 65 parts by weight, glass powder 25 parts by weight, bentonite 5 parts by weight, sodium carbonate powder 5 parts by weight, silicon carbide powder 0.
Mix 3 parts by weight uniformly, add 15 parts by weight of water to this, knead well, granulate with an extrusion type granulator having a large number of holes with a diameter of 1.2 mm, and then thoroughly dry to form granular ceramic foam. A sex composition was produced.

Shirasu powder 55 parts by weight, glass powder 25 parts by weight, bentonite 5 parts by weight, sodium carbonate powder 5 parts by weight, urexide powder 10 parts by weight, reddish brown pigment (enamel manufactured by Nisto Sangyo Co., Ltd.)
L-96) 3 parts by weight are uniformly mixed, and 15 parts by weight of water is added to this and kneaded well, granulated by an extrusion type granulator having a large number of holes of 1.2 mm in diameter, and then sufficiently dried. To produce granules of glaze.

Using the ceramic foam manufacturing apparatus 1 used in Example 1, the granulated ceramic foaming composition was fed onto the conveyor 2 to a thickness of about 27 mm, and the glazes granulated thereon to a thickness of about 5 mm. I put it. A ceramic foam was produced by heating and foaming in the same manner as in Example 1 except that the template was not placed.

The obtained ceramic foam has a thickness of about 43 mm and a specific gravity of 0.6.
And had a red-brown glaze-coated surface and was beautiful.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an example of a ceramic foam manufacturing apparatus used in the present invention. 2 ... conveyor, 5 ... main material hopper, 6 ... ceramic foamable composition, 7 ... glaze hopper, 8 ... glaze, 9 ... preheating furnace, 10 ... heating furnace, 11 ... slow cooling furnace , 12 ...
…Template.

Claims (1)

[Claims] 1. A granulated non-foaming glaze is placed on the granulated ceramic foamable composition and heated to a foaming temperature to foam the ceramic foamable composition into a ceramic foam. A method for producing a ceramic foam, which comprises baking glazes and then cooling.