JPH02631B2 - - Google Patents

Description

[Detailed Description of the Invention] (Objective of the Invention) Even when the shape of the baked product is modified, revised, or new, the spacer made of alumina can be used to replace the conventionally used spacer. This invention relates to a firing sheath using an attachment spacer for soft porcelain, which enables the firing of several different shapes of products using the firing sheath.

(Prior art) Conventionally, the compaction of bone china
As shown in the figure, a down-firing method is used. In the case of hard porcelain firing, this is SK9 to SK13 firing.
Compared to mullite and silica remaining, in the case of bone china, anorthite and β-tricalcium phosphate remain at SK8 to 9, resulting in drastic density changes and rapid vitrification. Low deformation resistance. For this reason, the desired product shape is obtained by a down-firing method that conforms to the chestnut surface of the shime-firing sheath.
Therefore, it is essential that the main shape of the chestnut surface of the sintered sheath be the same as the product shape.

Thus, when modifying or modifying the shape of the fired product, the shape of the chestnut surface of the firing sheath must also be changed. Conventionally, as a countermeasure to this problem, the method of manufacturing a new sintering sheath with the desired chestnut surface shape (1) or using the currently used carborundum material with excellent fire resistance and durability (1) A method (2) is adopted in which a fastening sheath 1A made of the same material is provided with an attachment 4 made of the same material. However method (1)
Since the work process starting from the production of the mold for molding the sheath takes a great deal of time and costs, the method (2) above is usually used. In addition, the cost amortization will be applied if the used sheath is disposed of only for the purpose of changing its shape while it still has a useful life remaining.
If the residual value is also taken into consideration, the economic loss will be extremely large.

On the other hand, the chestnut must have the same shape as the product as shown in Figure 5, so in order to do this, the top surface of the chestnut is inspected with a gauge, fired, and then coated on the surface. On the one hand, there is a complicated work process in which finishing is performed while checking again with a gauge, but since the material of the tochi is the same as that of the firing sheath, shrinkage during firing is large, and therefore firing distortion is also large. Cracks appear on the surface,
Due to defects such as peeling from the chestnut surface,
Periodic inspection and repair work was required.
In addition, since the attachment is attached to the surface of the shimeyaki sheath, peeling off this attachment will damage the top surface of the shimeyaki sheath, making it impossible to attach another attachment. Only different types of products could be shared.
Furthermore, it was necessary to use a press machine to form the chestnut, and therefore the cost of the mold for forming the chestnut was enormous.

(Structure of the Invention) The present invention eliminates these drawbacks and provides a product with a desired shape at low cost and easily. An example thereof will be explained with reference to FIG. Among the conventionally used compacting sheaths, a compacting sheath 1 (1A, 1
Select B) and form a dish-shaped product with a cross-sectional shape that corresponds to the gap between the product and the compacted sheath that shares the highly durable alumina slurry made of alumina refractories. Place the core of the attachment spacer 2 (2d), which was poured into a plaster mold and burned using this burning sheath, in a position that matches the core of the burning sheath 1 (1B), and then the product 3 (3d) is made. Place it on top and roast it. In mass production, the attachment spacer 2 is semi-fixedly installed by aligning the core of the attachment spacer 2 with the burning sheath 1.

For semi-fixed installation, use a gauge to mark the position of the attachment spacer 2 on the firing sheath 1, apply CMC (carboxyl, methyl, cellulose, organic glue) liquid in several places and welding glaze in between, and do not let it dry. Place the attachment spacer 2 according to the mark and fix it by gluing it, then dry it and weld it, or just bake it as is.
Used for firing and welding.

CMC is used for temporary fixing and is used to prevent the attachment spacer 2 from shifting its position during kiln firing, and will decompose and burn at the beginning of firing, but since the welding glaze will melt and solidify at the firing temperature. Does not cause misalignment. In addition, since the welding glaze is glassy and weak in strength, if an attachment spacer with a shape and size determined empirically to match the desired product shape is available, it can be done extremely easily and in a short time. Replacement work is possible.

As the current taste in ceramic products changes, diversified production methods of a wide variety of products and small quantities are required.
If sheaths of corresponding shapes were to be kept in stock, there would be a large number of types and numbers of sheaths, and as mentioned above, manufacturing them would require an extremely large amount of time and expense. Although circular spacers have been described in the embodiments, they are not necessarily circular, and the same applies to spacers of oval, square, etc. shapes.

(Operation of the Invention) The attachment spacer 2 installed to match the core of the compacting sheath 1 is formed with high precision by pouring alumina slurry into a plaster mold and compacting using the compacting sheath. Attachment spacer 2
Place the product 3 on top with their cores aligned, stack the required number of pieces, place them in a furnace, raise the temperature, and bake them.The product 3 will soften and conform to the attachment spacer 2 appropriately. , and shrinks to obtain a product 3 (3d) in the desired shape. In this case, it is necessary that it is supported at at least three points (bottom 5, rim 6, edge 7).

An alumina refractory is used for the attachment spacer 2, and its coefficient of thermal expansion is 6×10 -6 ℃ ^-1 , and a carborundum refractory is used for the compaction sheath, whose coefficient of thermal expansion is 6× ^{10 -6} ℃ -1. It is 4×10 ^-6 °C ^-1 . When using refractories made of other materials, it is generally desirable that the difference in thermal expansion coefficient be as small as possible. Practically speaking, the difference in expansion coefficient between the attachment spacer and the compaction sheath is preferably 3×10 ^-6 °C ^-1 or less.

(Effects of the invention) By adopting the present invention, it is possible to eliminate the above-mentioned drawbacks, and it is possible to make several types of attachment spacers by using alumina compaction by using the conventional compaction sheath as is. It is possible to easily exchange the compacted sheaths in several different shapes, and by using the semi-fixed attachment spacer method, it is possible to obtain products with stable shapes without displacement.

Therefore, the types of burning sheaths can be kept to a minimum, and the burning sheaths can be used as many times as needed, which reduces inventory management and factory management, and makes it easy to produce products with stable shapes. The present invention can improve the yield of the product, and the effects of the present invention on cost and production are extremely significant. Furthermore, by pouring alumina slurry into a plaster mold, no expensive molds are required for forming the attachment spacer.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view of the product 3a having the shape shown in Fig. 3 before compaction using a compaction sheath 1A designed for compaction, and Fig. 2 is a cross-sectional view of the product 3a having the shape shown in Fig. The cross-sectional view after firing, FIG. 3, shows the shape of the product 3a,
A is a front view, and B is a side and cross-sectional view. Fourth
Figures A and B show the shape of another product 3b, where A is a front view, B is a side view and a sectional view, and Figure 5 is a
Using the sheath 1A shown in the figure, a cross-sectional view of a product 3b after being compacted and fired using the conventional method, and FIG. 6 is designed to compact and fire a product 3c having the shape shown in FIG. 7. A cross-sectional view of the firing using the sheath 1B, Figure 8 shows the diameter,
Fig. 9 is a cross-sectional view of the products 3d with different heights and curves, which are compacted and fired using the attachment spacer 2d. It is. (Explanation of symbols of main parts), 1 (1A, 1B)
...Shining sheath, 2 (2d) ... Attachment spacer, 3 (3a, 3b, 3c, 3d) ... Product,
4... Atsushi, 5... Bottom, 6... Rim, 7... Edge tip.

Claims (1)

[Claims] 1. A dish-shaped attachment made of compacted alumina that has a cross-sectional shape that corresponds to the gap between the product and the compacted sheath to be shared, and which can be fitted in a replaceable manner with its core aligned with the center of the compacted sheath. A firing sheath using an attachment spacer, characterized in that it is equipped with an attachment spacer.