JPH11100284A - Manufacture of cellular ceramic article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently and accurately manufacture a cellular ceramic article having a bent or curved shape. SOLUTION: This manufacture comprises: a stage for firing a formed body of a cellular ceramic material to form a primary fired body 10; a stage (A) for firing the primary fired body 10 in such a state that the fired body 10 is placed on a shaping jig 20, to heat and soften the primary fired body 10; a stage (B) for deforming the heated and softened primary fired body 10 in conformity to the outer shape of the shaping jig 20; and a stage (C) for cooling the deformed fired body 10 together with the shaping jig 20 to manufacture the objective cellular ceramic article 14, wherein as the shaping jig 20, a jig having a shrinkable part 24 that can be subjected to shrinkage/deforming with cooling/shrinkage of the deformed fired body 14 is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a foamed ceramic product, and more particularly to a method for manufacturing a foamed ceramic product which is used as an exterior wall material of a building and is obtained by firing a foamable ceramic material. About.

[0002]

2. Description of the Related Art Foamed ceramic products are lightweight, excellent in strength, heat resistance, heat insulation, etc., and excellent in appearance, and are used as interior and exterior wall materials in general houses and other buildings. Have been. Most of ordinary foam ceramic products have a flat plate shape.

In order to manufacture a foamed ceramic product having a bent shape or a curved shape, it is conceivable to form the foamed ceramic material into a predetermined bent shape or a curved shape when molding the foamable ceramic material.

[0004]

However, since the foamable ceramic material is supplied in the form of powder and granules, it is relatively easy to deposit a flat plate and obtain a plate-like molded product. However, it is difficult to obtain a molded product having a complicated shape such as a bent shape or a curved shape. Further, even if the foamable ceramic material composed of powder and granules is deposited so as to form a predetermined bent shape or a curved shape, the shape of the deposited foamable ceramic material will be reduced in the subsequent handling and firing of the molded article. Is easily broken or deformed, and it is difficult to obtain a fired product having a molded bent or curved shape.

Further, when a plate-shaped molded product is fired, it has been considered that a molded product softened in the firing process, that is, a semi-baked product is bent by applying an external force, but it is difficult to form an accurate shape. Therefore, an object of the present invention is to efficiently and accurately manufacture a foamed ceramic product having a bent shape or a curved shape.

[0006]

A method of manufacturing a foamed ceramic product according to the present invention is a method of manufacturing a foamed ceramic material by molding and firing a foamable ceramic material, and includes the following steps. A step of firing a molded article of the foamable ceramic material to obtain a primary fired article.

A step of firing the primary fired article in a state where the primary fired article is arranged on the molding jig and deforming the heat-softened primary fired article along the outer shape of the molding jig. A step of cooling the deformed fired product together with a molding jig to obtain a foamed ceramic product. Further, as the molding jig, a jig having a shrinkable portion which is reduced and deformed in accordance with cooling shrinkage of the fired product is used.

[0008] Each component will be specifically described. [Foamed ceramic product] As the foamable ceramic material used as the raw material of the foamed ceramic product, the same material as the foamable ceramic material used for ordinary building materials is used. Specifically, a powder obtained by adding a foaming agent to glass powder, soda ash, or the like, pulverizing the powder, or granulating after pulverization is used.

[0009] A multilayer ceramic foam product can be manufactured by laminating a plurality of types of foamable ceramic materials having different colors and characteristics. Foamed ceramic with a laminated structure of a base layer having a foamed structure that exhibits basic properties such as mechanical strength, and a decorative layer that has a non-foamed structure by covering the surface of the base layer and exhibiting appearance and surface properties You can also get products. For the decorative layer, a material obtained by removing a foaming component from a foamable ceramic material or a glaze material can be used. Glass particles for decoration and the like can also be arranged. [Shaping] A layered molded product can be obtained by supplying a powdery and granular foamable ceramic material to the surface of a belt conveyor or the like and depositing it in a layered manner. If a plurality of foamable ceramic materials are sequentially deposited in layers, a laminated molded product can be obtained. As the decorative layer, a layer made of a material other than the foamable ceramic material can be combined.

[0010] A foaming ceramic material in the form of a granular material or a slurry can also be molded using a molding die.
The shape of the molded product may be not only a simple layer or a plate, but also may have irregularities or a penetrating portion. [Primary firing] The molded article is fired using a normal firing furnace or firing apparatus. Since the baking is performed again after the primary baking, it is not necessary to perform the baking to the final stage in this primary baking. Of course, the firing may be substantially advanced to the final stage. [Molding jig] It is made of a heat-resistant material that can be fired with the primary fired product placed. The outer shape of the molding jig is designed according to the shape in which the primary fired product is desired to be deformed.

For example, when the primary fired product is to be bent into a U-shape, a molding jig having a rectangular or U-shaped cross section is used. If you want the primary fired product to be bent into an L-shape,
A molding jig having an upwardly convex right-angle cross section is used. When it is desired to deform the primary fired product into a curved shape, a curved surface may be provided on the molding jig, or a small bent portion may be arranged in a curved shape.

The shrinkable portion is made of a material that is easily reduced and deformed when an external force in the pressing direction is applied, or if the material itself is hardly deformed but has a mechanism that can be easily reduced in structure. Good. Specifically, a refractory material such as ceramic wool is used as the shrinkable portion. A mesh material made of stainless steel or the like is also used. A laminated plate in which a large number of thin plates of stainless steel or the like are laminated with a gap capable of being reduced is also used. In any case, it has heat resistance to withstand the heating temperature in the step of deforming the primary fired product.

If the entire jig is a shrinkable portion, it can be reduced and deformed by an external force from any direction. This is effective when the direction and location of cooling shrinkage of the fired product are not clear, or when cooling shrinkage occurs in a plurality of directions and locations. However, it is necessary to have a deformation resistance to such an extent that the fired product is not easily deformed by the force of its own weight. A molding jig including a shrinkable portion and a rigid portion that is not easily reduced and deformed is also used. The rigid portion is made of a refractory metal such as stainless steel or a refractory ceramic.

In this case, the shrinkable portion is arranged only at a position or a direction where a large force is applied by the cooling shrinkage of the fired product,
It is preferable to dispose a rigid portion at a position necessary for maintaining the shape of the entire jig and supporting the fired product. When arranging the rigid parts in a plurality of places, if the rigid parts are connected to each other with a shrinkable part and arranged so that the rigid parts are movable with respect to each other,
Due to the movement of the rigid portion due to the contraction of the shrinkable portion, distortion due to cooling shrinkage of the fired product can be favorably absorbed. [Firing Deformation] The primary fired product is deformed along the outer shape of the molding jig by firing the primary fired product to the final stage and heating and softening the primary fired product in the firing process.

It is necessary to maintain the heating at least at a temperature higher than the yield point at which the primary fired product is softened, until the deformation of the primary fired product is completed. Usually, firing is performed at a temperature 30 to 100 ° C. higher than the yield point. An external force can be applied to the softened primary fired product to forcibly bend it. If a notch or a groove is formed in a portion of the primary fired product that is desired to be bent, a part of the thickness of the primary fired product is easily bent when the primary fired product is softened. [Cooling] The fired product given the desired deformation in the previous process is
When firing is completed and cooled to a temperature below the yield point, the shape is fixed and a final fired product, that is, a foamed ceramic product is obtained.

The cooling can be carried out by slow cooling in the firing furnace, by leaving the firing furnace for cooling, or by forced cooling. During the cooling process, the ceramic foam product undergoes a large cooling shrinkage. In particular, significant cooling shrinkage tends to occur during passage through the temperature from the yield point to a slightly lower range.

In the molding jig, the material shrinks with cooling, but the cooling shrinkage of the material of the molding jig is negligibly small as compared with the cooling shrinkage of the foamed ceramic product. Therefore, the shrinkage force generated due to the cooling shrinkage of the final fired product,
It works in the direction to reduce the molding jig. If the molding jig is not reduced, a reaction force from the molding jig is applied to the foamed ceramic product, and a large internal stress is generated in the foamed ceramic product, which causes problems such as cracks, chipping, and residual strain.

If the molding jig is provided with a shrinkable portion, the shrinkable portion is reduced by the force applied to the molding jig, so that a large reaction force does not act on the foamed ceramic product. Once the foamed ceramic product has cooled to near room temperature, no further cooling shrinkage occurs. At this stage, the foamed ceramic product may be removed from the molding jig. If the removed jig has a shrinkable portion having a restoring property, it returns to its original shape by the restoring force of the shrinkable portion, and the jig can be reused.

[0019]

FIG. 1 shows a step-by-step process of manufacturing a foamed ceramic product. A plate-shaped primary fired product 10 is prepared in advance. The primary fired article 10 has a laminated structure of a base layer 12 made of foamed ceramic and a decorative layer 11 made of a non-foamed dense ceramic layer covering the surface of the base layer 12.

In the production of the primary fired article 10, a molded article prepared in advance is fired. The molded article is manufactured by depositing a granular foamable ceramic material in layers to form a base layer, depositing a foaming agent-free ceramic material on the base layer, and laminating a decorative layer. . When the obtained molded product is fired and printed in a firing furnace, a primary fired product 10 is obtained. FIG.
As shown in (A), the plate-shaped primary fired product 10 is placed on the upper surface of a molding jig 20.

As shown in FIG. 2, the molding jig 20 has a frame shape having a rectangular cross section as a whole, and includes a rigid portion 22 and a shrinkable portion 24. The rigid portions 22 are arranged at an interval on the left and right, have a substantially U-shaped cross section, and are made of a non-deformable material such as stainless steel. The compressible portion 24 connects only the upper portions of the rigid portions 22, 22 at the center of the left and right rigid portions 22, and is made of a material such as ceramic wool that is easily compressed and deformed.

When a force is applied so as to compress and shrink the rigid portions 22, 22, the central shrinkable portion 24 is compressed and deformed, so that the entire width of the molding jig 20 is reduced.
The primary fired product 10 placed on the upper surface of the molding jig 20
The left and right ends protrude slightly from both ends of the molding jig 20. As shown in FIG. 1 (B), the primary fired product 10 is placed in a firing furnace while being placed on a molding jig 20 and fired. Due to heating during firing, the primary fired article 10 is softened. The heating temperature is set to a temperature that slightly exceeds the yield point of the primary fired article 10.

The softened primary fired product 10 is used as a mold jig 2
The ends that are not supported at 0 hang down under their own weight, and deform so as to bend at right angles along both side surfaces of the molding jig 20. The overall shape of the deformed fired article 10 is a flat U-shape having short bent portions 10a bent at right angles on both sides of a flat main body. As shown in FIG. 1 (C), the primary fired product 10 is fired to the final stage to become a final fired product, that is, a foamed ceramic product 14. The foamed ceramic product 10 is cooled while being placed on the molding jig 20. It may be cooled in a firing furnace, or may be taken out of the firing furnace and cooled.

The foamed ceramic product 14 undergoes cooling shrinkage during the cooling process, and is deformed so that the left and right bent portions 14a move toward the inside. The molding jig 20 pressed by the left and right bent portions 14a is reduced in the centrally deformable shrinkable portion 24 so that the bent portion 1 of the foamed ceramic product 14 is deformed.
Absorb the force applied from 4a. As a result, no excessive repulsion or resistance from the molding jig 20 acts on the foamed ceramic product 14, and no excessive stress is generated on the foamed ceramic product 14. Cracks and residual stress hardly occur in the foamed ceramic product 14.

FIG. 5 shows the temperature change of the primary fired product 10 (or the foamed ceramic product 14) during the firing and cooling processes. In section a, the temperature rises with the start of firing. When the temperature exceeds the yield point Tx, the temperature enters the section b, and the softened product of the primary fired product 10 starts. After the temperature is raised to a temperature 30 to 100 ° C. higher than the yield point Tx, the heating is stopped and the temperature is lowered. When the temperature falls below the yield point Tx, the section enters the section c, and the shape of the foamed ceramic article 14 returns to room temperature after the foamed ceramic article 14 is further cooled from the fixed yield point Tx. In this section c, cooling contraction of the foamed ceramic product 14 occurs. In particular, the yield point Tx
Since the thermal expansion coefficient of the foamed ceramic product 14 is large in a region close to the temperature range, a large cooling shrinkage occurs when passing through the temperature region.

The manufactured foamed ceramic product 40 having a U-shaped cross section is then subjected to the same finishing processing as a normal foamed ceramic product, and then used as a building material. [Another Embodiment 1 of Molding Member] The molding member 20 shown in FIG. 3 has the same basic outer shape as that of the embodiment shown in FIG. 2, but is entirely made of a stainless mesh material. Since the stainless mesh material is easily deformable, the entire molding member 20 becomes a shrinkable portion.

The same operation process as described above can be performed by placing the primary fired article 10 on the upper surface of the molding member 20. In addition,
When the foamed ceramic product 14 contracts by cooling, the entire upper side of the molding member 20 is reduced in the horizontal direction to absorb the distortion. [Another Embodiment 1 of Molding Member] The molding member 20 shown in FIG. 4 has a substantially triangular mountain shape as a whole. It has a rigid body part 22, 22, which has a re-shape, and a compressible part 24 arranged at the upper center thereof.

The plate-shaped primary fired product 10 similar to the above is placed on the molding member 20 and the same firing deformation step as described above is performed. The primary fired article 10 is bent at a right angle from the center along the upper surface shape of the molding member 20. In the cooling process, the chevron-shaped foam ceramic product 14 contracts by cooling and shrinks toward the center. In the molding jig 20, the central shrinkable portion 24 is reduced,
The shrinkage of the foamed ceramic product 14 is absorbed. [Blending of expandable ceramic material] A blending example of a expandable ceramic material suitable for producing the above-mentioned foamed ceramic product and a firing temperature are shown below. -Formulation Example 1-Base layer 64.5% Otani stone 18% Soda ash 18% Water glass powder 5% Sanitary talc 12% SiC 0.5% Cosmetic layer Glass powder 62% (Granulated powder) Frit 25% Elutriation clay 5% Zirconium silicate 8% Baking temperature 900 ° C-Formulation example 2-Base layer Horse head clay 61.6% Dry water glass 5% Soda ash 20% Sanitary talc 10% SiC 0.4% ZnO 3% Cosmetic layer Plate glass particles (0.3 100% to 50% (crushed particles) Frit particles (0.3 to 5mm) 50 to 0% Firing temperature 900 ° C-Formulation example 3-Base layer Pearlite 57% Glass powder 27% Borax 8% Soda ash 6% Sodium nitrate 2% Cosmetic layer Frit 25% (granulated powder) Glass powder 70% Elutriation clay 3% Bentonite 2% Firing temperature 780 ° C

[0029]

According to the method for producing a foamed ceramic product of the present invention, the primary fired article placed on the molding jig is heated and softened and subjected to deformation processing along the molding jig. An exactly corresponding foam ceramic product is obtained. In addition, since the shrinkage of the foamed ceramic product during cooling shrinkage is absorbed by the shrinkage of the shrinkable portion of the molding jig, excessive stress and distortion are less likely to occur in the foamed ceramic product during the cooling process of the foamed ceramic product, and cracks are generated. This can prevent the occurrence of chipping or chipping.

[Brief description of the drawings]

FIG. 1 is a schematic process diagram showing an embodiment of the present invention and showing a manufacturing process step by step.

FIG. 2 is a perspective view of a molding jig.

FIG. 3 is a perspective view showing another embodiment of a molding jig.

FIG. 4 is a cross-sectional view illustrating another embodiment of a molding jig.

FIG. 5 is a graph showing a temperature change in a firing process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Primary fired article 10a, 14a Bending part 14 Foamed ceramic product 20 Molding jig 22 Rigid body part 24 Shrinkable part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI E04C 2/04 E04C 2/04 F 2/30 2/30 C

Claims (3)

[Claims] 1. A method for producing a foamed ceramic product by molding and firing a foamable ceramic material, comprising: firing a molded article of the foamable ceramic material to obtain a primary fired product; Is fired in a state where it is arranged in a molding jig,
Deforming the heat-softened primary fired product along the outer shape of the molding jig, and cooling the deformed fired product together with the molding jig to obtain a foamed ceramic product, wherein the molding jig includes: A method for manufacturing a foamed ceramic product using a shrinkable portion which is shrunk and deformed by cooling shrinkage of a deformed fired product. 2. The method according to claim 1, wherein the molding jig includes a plurality of rigid portions.
The method for producing a foamed ceramic product according to claim 1, wherein a member having the shrinkable portion connecting the rigid portions is used. 3. The method for producing a foamed ceramic product according to claim 1, wherein the molding jig is a molding jig entirely formed of a shrinkable portion.