JPS6110075A - Method of burning green ceramic - 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 [Technical Field] The present invention relates to a method for firing oxide-based green ceramics formed by adding an organic binder.

[Background technology]

The firing process has traditionally been a time-consuming and costly process in the manufacturing process of ceramic products, and it has been desired to perform it efficiently.

At the beginning of the firing process, the binder of green ceramics is removed. At this stage, the organic binder is not decomposed and the oxygen in the atmosphere in the furnace is not sufficiently diffused into the body to be fired. If the movement of the products does not proceed smoothly enough, there are problems such as cracks occurring and residual carbon forming carbide, which becomes foreign matter and remains in the product. Further, in the sintering step after step 7, uneven temperature distribution, uneven shrinkage due to residual stress during molding, warpage, etc. may occur.

[Object of the Invention] In view of the above-mentioned problems, the present invention provides ceramic products that are efficient and free from cracks, distortions, etc.
The purpose of this study is to provide a method for firing green ceramics that can be produced using green ceramics.

[Disclosure of the invention]

In order to achieve the above object, the present invention divides the firing process into two stages, a calcination process and a sintering process, when firing green ceramics formed by adding an organic binder. The green ceramics are calcined so that the total surface area of all the green ceramics in contact with the atmosphere is as large as possible, and the total volume of all the calcined materials in the furnace is increased in the sintering process. Its gist is the firing method. That is, in the calcination process (de-binding process), the total surface area of all green ceramics is increased, the diffusion time of oxygen etc. is shortened, the temperature rise speed is increased, and the calcination for debinding is performed. Therefore, in the sintering process, a large number of calcined materials are piled up and the calcined materials are sintered in a manner that improves the volumetric efficiency of the firing furnace. An example of this will be explained in detail below based on the accompanying drawings.

FIG. 1 (ω is an example of the calcination step in the green ceramics firing method according to the present invention. In this example, the green ceramics 1 are in the shape of a flat plate. The green ceramics 1 are placed in a facing shape. Placed jig 2, 2
The sheets are inserted one by one into the recesses #lI3 provided at appropriate intervals on each inner surface of the sheet, and the sheets are clamped and fixed from both sides, and vista firing is performed in a furnace. During firing, the temperature of the green ceramic 1 is raised at a high speed in such a way that it is dangerous to directly receive radiation es from the heat source. Since the green ceramics are provided with an appropriate gap from each other by the convex portions 11vC of the jigs 2 and 2, the green ceramics can come into contact with the atmosphere in the blade furnace in a state where the total surface area is maximum. The green ceramics (calcined) t after the calcination step are piled up in a V shape on a spherical ceramic powder 5 and sintered, as shown in FIG. 1(b).

When the green ceramics have a concave shape, firing is performed as shown in FIGS. 2(a) and 2(b). That is,
First, as shown in Figure 2 (a), the concave green ceramics 6 is placed in a pod 7 with its four parts facing down. Appropriate gaps are provided between each of the concave green ceramics 6 and the earthen floor, and they are arranged so as not to be in close contact with each other. A plurality of pods 7 containing these green ceramics are piled up and vista-fired in a furnace to perform a calcining process. After this step, the calcined product 6' is
Figure 2 (Pile up many ceramics in the same direction as shown in ω and sinter them.) If the green ceramic is in the shape of a hemispherical shell, the third
The methods shown in Figures (a) and (b) are preferable. That is, the hemispherical green ceramic 8 is placed face down with its opening facing down, and supported on a conical jig 9 so that a gap is created below. In this way, the green ceramics 8 supported by the jig 9 are arranged in a furnace and a calcining process is performed. After that, the calcined product 8' is
As shown in FIG. 3(b), a large number of them are stacked face down with their openings facing down and sintered. Box-shaped green ceramics may also be calcined and sintered in the same manner using a truncated cone or truncated pyramid jig.

〔Effect of the invention〕

Since the present invention is configured as described above, the green ceramics can be evenly contacted with the atmosphere in the furnace, and the calcination process (depine mite removal process) can be performed smoothly. Therefore, it is possible to obtain a high quality ceramic product without cracks or distortion. In addition, the firing process, which was conventionally performed in one furnace, can be divided into two, so the furnace can be separated, and harmful gases are generated on the furnace wall, heater, etc. This is a calcining (debinding) furnace. This eliminates the need to raise the temperature to high temperatures, and the sintering needle, which heats up, does not emit harmful gases, extending the life of the furnace.

The sintering process involves stacking a large number of green ceramics (calcined materials) one on top of the other, making it highly efficient and reducing costs.

[Brief explanation of drawings]

@1 Figures (a) and (b) are a perspective view showing the calcination process and an explanatory view showing the sintering process in an embodiment of the green ceramics firing method according to the present invention, and Figures 2 (a) and (b) FIG. 2 is a cross-sectional view of a main part showing another process and a partial cross-sectional view showing a sintering process. 1.6.8...Green ceramics r, 6'. 8'...Calculated product 2,9...Jig 7...Saya agent Patent attorney Takehiko Matsumoto (b) (b)

Claims (4)

[Claims] (1) When firing green ceramics formed by adding an organic binder, the firing process is divided into two stages: a calcination process and a sintering process. During the calcination process, the total surface area of all the green ceramics in contact with the atmosphere in the furnace is A method for firing green ceramics, which is characterized in that calcining is performed so that the amount of the calcined material is as large as possible, and in the sintering process, the total volume of all calcined materials in the furnace is increased. (2) When the green ceramics are flat, a jig is used in the calcination process to arrange the green ceramics vertically with gaps between them, and in the sintering process, each calcined product is placed horizontally. The method for firing green ceramics according to claim 1, wherein the green ceramics are stacked together. (3) When the green ceramics have a concave shape, the green ceramics are housed in a sheath with gaps between them in the calcination process, and the calcined products are piled up in the same direction in the sintering process. range 1
Firing method for green ceramics as described in section. (4) When green ceramics have a hemispherical shell shape,
During the calcination process, the opening of the green ceramics is placed downward.
A patent that uses a conical jig to cover the face-down green ceramics with the jig, leaving a gap under the ceramics, and in the sintering process, each calcined product is stacked face-down close together. A method for firing green ceramics according to claim 1.