JPS6283384A - Manufacture of ceramic foam formed body - 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 [Industrial Field of Application] The present invention relates to a method of manufacturing a ceramic foam molded article.

[Conventional technology]

Conventionally, in order to produce molded ceramic foam products, a foamable composition is heated to a high temperature of 700 to 1300°C to foam, and then the foam is cooled while still hot (while still plastic) using a cooled template or roll. A method of molding was used.

[Problem that the invention seeks to solve]

However, when molded using this conventional method, fine racks were formed on the surface of the ceramic foam, making it impossible to obtain a molded product with a beautiful surface.

The inventors believe that this phenomenon occurs because only the surface of the ceramic foam, which is still hot and plastic, is rapidly cooled by the cooled template or roll, and the template or roll remains hot without being cooled. When molding was carried out, the ceramic foam adhered to the template or roll, making it impossible to obtain a good molded product.

Therefore, as a result of further research, the inventors discovered that by interposing inorganic powder between the ceramic foam and the template or roll, it was possible to prevent the adhesion of the ceramic foam and completed the present invention. It is something that

[Means for solving problems]

That is, one gist of the present invention is a method for producing a ceramic foam molded article by heating and foaming a foamable composition and molding the foam while the foam is still plastic. The method of manufacturing a ceramic foam molded article is characterized in that an inorganic powder or granular material is provided on the surface of the ceramic foam molded article, and the molded article is then molded using a template or a roll.

The foamable composition used in the present invention refers to volcanic ejecta such as shirasu, anti-firestone, basalt, andesite, and 700 to 1
These include powders of inorganic substances that melt at 300° C. mixed with blowing agents such as silicon carbide and carbon black, or compositions of these with softeners such as soda ash and sodium silicate added. It also includes inorganic substances that foam when heated alone, such as obsidian, pinestone, and pearlite.

The inorganic powder used in the present invention preferably has good heat resistance and does not melt at the temperature of heating and foaming.

As the powder, for example, alumina powder, silica sand powder, etc. are often used. Further, as the particles, for example, silica sand, white silica sand, chromite sand, zircon sand, etc. are used.

In the present invention, when heating and foaming the foamable composition, it may be used as a powder, or it may be granulated into granules, or it may be formed into a desired shape. good.

These foamable compositions are placed on a metal plate or wire mesh provided with a mold release agent such as alumina powder, or on a refractory material such as firebricks, and placed in an electric furnace, gas furnace, or oil furnace. Add to heat and foam.

The inorganic granules are placed on the surface of the heated and foamed ceramic, and molded using a template or roll while the ceramic is still plastic.

In this way, in the present invention, after heating and foaming, inorganic powder is provided on the surface of the foam while it is still hot and plastic.

This is because if inorganic powder or granules are placed on the surface of a foamable composition before foaming, the composition will move significantly during foaming, causing cracks on the surface and causing the foam to pass between the powders and granules onto the surface. This is because if the exposed foam is molded using a template or roll, the exposed foam will adhere to the template or roll, making it impossible to produce a good molded product.

The molded plate used in the present invention may be a flat plate or may be engraved into an appropriate shape. Similarly, the surface of the roll may be smooth, or it may be engraved into an appropriate shape.

When such a molded plate or roll is slowly cooled, a ceramic foam molded product can be obtained.

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

FIG. 1 shows a method for manufacturing ceramic foam tiles in a batch system.

11 indicates a lower mold, and 15 indicates an upper mold.

A solution prepared by dispersing alumina powder in water is applied onto the lower mold 11 and thoroughly dried. A powdered foamable composition 12 is placed thereon so as to have a substantially uniform thickness, and this is placed in an electric furnace, heated to a foaming temperature, and foamed. Alumina powder 14 is uniformly dispersed on the sufficiently foamed material 13.

The upper mold 15, which has been heated in advance to near the foaming temperature, is placed on top of the upper mold 15, and molded under pressure.

When this state is slowly cooled to near room temperature, a tile-shaped ceramic foam is completed.

The alumina powder adhering to the surface was removed by washing with water, and a ceramic foam molded product with a beautiful appearance was obtained.

FIG. 2 shows an embodiment of the process for production in a continuous furnace.

Reference numeral 21 denotes an endless mesh wire gauze, and a liquid 22 in which alumina powder is dispersed is applied to the surface of the endless mesh wire gauze to adhere the alumina powder to the surface. Granular foamable composition 31 is placed on this endless belt 21 to a uniform thickness.

This foamable composition 31 is heated to about 950° C. while passing through the heating furnace 23 and foams to become a foamed body 32 . When the foam is sufficiently foamed, No. 5 silica sand 41 is transferred to the distribution device 42.
Place it evenly on the foam 32.

As shown in FIG. 3, the distribution device 42 includes a hopper 43,
It has a screw conveyor 44 and a distribution pipe 45.

Then, the silica sand 41 is put into the pumper 43 protruding from the outside of the heating furnace 23 of the distribution device 42, and the screw conveyor 4
4, it is transported to the distribution pipe 45 inside the heating furnace 23.

The distribution pipe 45 is provided with a slit 46 around its periphery that becomes lower as it goes deeper. As the silica sand 41 advances through the distribution pipe 45, it spills out from the slit 46, and the smaller the amount in the distribution pipe 45, the lower the slit 46 becomes. Silica sand 41 is placed uniformly in the entire direction.

When the foam 32 comes out of the heating furnace 23 into the slow cooling device 24, it is immediately pressed by forming rolls 25 while still being plastic, and becomes a ceramic foam 33 with a desired thickness. The foam 33 that has passed through the slow cooling device 24 is cut into a predetermined length by a cutting device 26 to form a plate.

This plate of ceramic foam 33 had an excellent appearance as an outer wall with silica sand adhered to its surface.

〔Effect of the invention〕

In the present invention, as described above, inorganic powder is provided on the surface of the foam while it is still plastic enough to easily adhere, and molding is performed from above using a template or roll. A beautiful molded product can be obtained without any adhesion.

Furthermore, if silica sand or other powder with a beautiful appearance is used as the inorganic powder, it is possible to obtain a beautiful molded product in which the powder is attached to the surface of the ceramic foam.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a method for manufacturing a ceramic foam molded product of the present invention using a batch system, FIG. 2 is an explanatory diagram showing a method for manufacturing a ceramic foam molded product according to the present invention using a continuous method, and FIG. FIG. 2 is an explanatory diagram illustrating the distribution device shown in the figure. 12... Foamable composition, 13... Foam, 14...
- Alumina powder, 15... Upper mold, 25... Molding roll, 31... Foamable composition, 32... Foam, 41
...silica sand.

Claims (1)

[Claims] 1. In a method for manufacturing a ceramic foam molded article by heating and foaming a foamable composition, the foamable composition is heated and foamed, and while the foam is still plastic, inorganic powder is added. A method for manufacturing a ceramic foam molded article, which comprises providing the ceramic foam molded article on its surface and then molding the ceramic foam molded article from above using a template or roll.