JPH0657618B2 - Manufacturing method and equipment for ceramic products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method for manufacturing a ceramic product and an apparatus therefor.

(Prior art) Ceramic products such as vases, jars, sanitary ware (Western-style toilets, etc.),
When making insulators, the material, such as kneaded clay, is molded into a semi-finished product, and primary drying (unbaked, water content 20-25% is 1
The product is generally dried (0 to 15%), coated with a laxative, and then baked to complete the product.

In this process, after forming kneaded clay etc., at the stage of semi-finished product,
When the object is stored or moved, it may be deformed at a portion having insufficient mechanical strength because it is a soft material such as clay. Especially, when the humidity is high during the rainy season, such a phenomenon appears remarkably.
Further, if the water content is lowered to perform the molding in order to prevent the deformation, it may be difficult to mold a complicated shape or cracks may occur.
In the case of a complicated shape, some molded products are made and joined together, but if the water content is lowered to the extent that they are not deformed, the joints may not be sufficiently fused.

(Problems to be Solved by the Invention) In the conventional semi-finished product storage state as described above, the semi-finished product may be deformed at a portion where the mechanical strength is insufficient, or the material may be deformed in order to prevent the deformation. If the water content is reduced, complicated molding becomes difficult and the semi-finished product is cut.

This invention utilizes a microwave energy immediately after molding into a semi-finished product to heat a part of the semi-finished product having insufficient mechanical strength and evaporate some water to strengthen the part having insufficient strength. It is an object to provide a manufacturing method and an apparatus thereof.

[Structure of the Invention] (Means for Solving Problems) This invention irradiates a semi-finished product immediately after molding, which is easily deformed, with a microwave to heat the semi-finished product, and evaporates the water content of the irradiated part to reduce the water content. A method of manufacturing a ceramic product characterized by decreasing the temperature rise value of the microwave irradiation portion,
The temperature is set to 5 to 20 ° C., and the decrease value of the water content of the microwave irradiation portion is set to 2% or less compared to before irradiation.

Further, according to the present invention, two waveguides connected to a microwave oscillator are arranged so as to face each other in the oven so as to penetrate from both sides,
A manufacturing apparatus for a ceramic product, characterized in that a semi-finished product of the ceramic product is apt to be deformed in a space between both waveguides and is irradiated with microwaves.

(Operation) According to the present invention, the semi-finished product is not deformed, the quality is improved, and the yield is good. In addition, even complicated shapes can be molded, and it is possible to easily connect and fuse multiple molded semi-finished products.

Embodiment An embodiment of the present invention will be described in detail below with reference to the drawings.

Taking a pot 11 as shown in FIG. 1 as an example of a ceramic product, when this pot 11 is manufactured, the A part (hatched part) is stored during the storage until the first drying after molding the material. Although it may be deformed due to the weight above the jar 11, according to the present invention, the portion of the semi-finished product which is easily deformed is irradiated with microwave power to heat and strengthen the material after the material is formed and before firing. To do.

As a heating method in this case, in addition to microwave power, there is an external heating method such as a heater, flame, or hot air.
Since these methods apply heat from the outside, the temperature gradient between the surface layer portion of the semi-finished product, the inside and the inner surface of the semi-finished product becomes large, and it is not preferable because it breaks (cracks) and the drying of the surface layer portion is promoted. On the other hand, the microwave can heat the surface layer portion and the inside substantially uniformly, the above-mentioned defects do not occur, and the strength of the semi-finished product can be improved.

Therefore, first, an apparatus used in the manufacturing method of the present invention, that is, a microwave heating apparatus will be described.

This microwave heating device is configured as shown in FIGS. 3 and 4, FIG. 3 is a front view, and FIG. 4 is a side view. That is, two waveguides 22A and 22B respectively connected to the microwave oscillators 21A and 21B penetrate through the oven 23 from both sides and are arranged to face each other at a predetermined interval. Furthermore, the oven 23 has an inlet 23A and an outlet 23 through which a ceramic product, for example, a semi-finished product 25 of a pot, passes.
B is provided, and doors 28A and 28B for preventing microwave leakage are provided so as to be openable and closable by a cylinder drive or the like.

The jar half-finished product 25 is placed on a tray 26 and is conveyed by a conveyor, for example, a roller conveyor 27, and its driving device is composed of a motor and a speed reducer (not shown). It is necessary to drive the roller conveyor 27 in the oven 23 outside the oven 23, and the through shaft portion uses a λ / 4 choke or the like so as to prevent electric wave leakage. Further, the heating target position of the semi-finished pot 25 (two-dot chain line in FIG. 3) and the waveguides 22A, 22B.
A sensor 29 such as a photoelectric switch is provided in order to detect the mutual relationship between the two.

Now, in order to heat the pot semi-finished product 25 by using the microwave heating device as described above, the tray 26 on which the pot semi-finished product 25 is placed is placed on the roller conveyor 27, and the inlet side door 28A of the oven 23 is set. Open it and put the semi-finished product 25 in the jar into the oven 2.
It is sent to the inside of 3 by the roller conveyor 27, and the sensor 29
And the roller conveyor 27 is stopped.

In this case, the sensor 29 detects the time when the semi-finished pot product 25 passes, but the position of the sensor 29 may be changed to stop when the semi-finished pot product 25 arrives. Which is adopted is the pot. It may be selected from the relationship between the detection position of the semi-finished product 25 and the portion to be heated. After the semi-finished product 25 enters the oven 23, the entrance side door 28A is closed, a predetermined power source is applied to the microwave oscillators 21A and 21B to generate microwaves, and the microwaves are generated through the waveguides 22A and 22B. The product 25 is irradiated with microwaves. Then, the semi-finished product 25 absorbs microwaves to generate heat, and when the temperature reaches a predetermined temperature, the microwave oscillation is stopped.

After that, the exit side door 28B is opened, and the roller conveyor 27
To drive the semi-finished product 25 out of the oven 23.

As a matter of course, when the semi-finished products 25 are continuously processed, as shown in FIG. 3, the tray 26 on which the semi-finished products 25 are placed may be placed on the roller conveyor 27 and sequentially moved.

(Modification of Device) In the above embodiment, the microwave power is supplied from the left and right of the semi-finished product 25 by one microwave oscillator at a time, but if the semi-finished product 25 of the ceramic product such as a jar becomes large, Of course, a plurality of microwave oscillators may be used. In this case, the portion of the waveguide located in the oven 23 is
A shape as shown in FIG. In the figure, 30A, 30B and 31A, 31B are microwave oscillators, 32A, 32B and 33A, 33B are waveguides, and the ovens 23 of the waveguides 33A, 33B are one.

Further, in the above-mentioned embodiment, the waveguides 22A and 22B are used in the horizontal direction, but it goes without saying that depending on the shape of the semi-finished product 25, it can be changed upward, downward, or obliquely.

Now, an experiment conducted by the inventor using the above-described device will be described.

The jar 11 used in the experiment has a shape as shown in FIG. 1, and its initial conditions are as follows.

* Non-treated material ………… Bottle ＊ Weight ………… 6Kg ＊ Water content ………… 25% ＊ Initial temperature …… 20 ℃ You can heat this jar about 10 ℃. The heating result is as follows. Met.

* Microwave output: 3 KW (frequency) * Irradiation time: 45 seconds * Hatching area: 27 to 31 ° C * Water content after processing: 24% In this example, part B is 35 by heating due to the end effect
There was a problem that the temperature was up to 36 ° C. and the drying was promoted slightly, but this can be solved by devising such as irradiating the heating target portion with the microwave irradiation method intensively.

Further, the state of the semi-finished product 25 when the irradiation time was changed is checked in the following table. The initial conditions of the semi-finished product are almost the same as above. As the experimental machine, a semi-finished product was used in which microwaves were concentrated and applied to a portion to be heated.

These temperature rise values and water contents are the values of the part to be heated, and other parts are naturally between the initial conditions and this value.
From this, the temperature rise is about 5 to 20 ° C, and the decrease in water content is 2
It was found to be below%.

Next, an example of heating with sanitary ware will be described. The sanitary ware is as shown in FIG. 2, but the C part may be deformed. The initial conditions are as follows.

* Non-treatment area: Sanitary ware * Weight: 25 kg * Water content: 24% * Initial temperature: 19 ℃ When heated at a microwave output of about 6 kW and irradiation time of 20 seconds, C The reached temperature of the part (hatched part) is 28 to 3
At 1 ° C, the water content was 23%, and the initial purpose was achieved.

[Effects of the Invention] According to the present invention, the following excellent effects are obtained.

The semi-finished product 25 is not deformed and the quality is improved.

Deformation of semi-finished product 25 that occurred frequently during the rainy season disappeared,
The yield is greatly improved.

Since it is no longer necessary to reduce the water content of the material indiscriminately, it is possible to mold even complicated shapes, and cracks (cracks)
Will not enter.

It also becomes possible to easily connect and fuse a plurality of semi-finished products 25.

Further, as an effect of the device of the present invention, it is possible to irradiate microwave power to a necessary portion of the semi-finished product 25 very easily.

The edge effect eliminates overheating.

Since the microwave power is intensively applied to the required part of the semi-finished product 25, the temperature rise of other parts is small and the microwave energy can be effectively used.

[Brief description of drawings]

FIG. 1 is a front view showing a pot which is an example of a ceramic product applied to a method for manufacturing a ceramic product according to an embodiment of the present invention.
The figure is a front view showing a sanitary ware which is another example of a ceramic product, and FIGS. 3 and 4 are a front view and a side view showing a manufacturing device for a ceramic product according to an embodiment of the present invention, and FIG. (A),
(B) is a side view which shows the modification of the manufacturing apparatus of a ceramic product. 11 ... urn (ceramic product), 21A, 21B ... microwave oscillator, 22A, 22B ... waveguide, 23 ... oven, 25 ... semi-finished product.

(72) Inventor Hidetoshi Hayashi 72 Horikawa-cho, Sachi-ku, Kawasaki-shi, Kanagawa Toshiba Electronic Device Engineering Co., Ltd. (72) Masakazu Toyoshima 72 Horikawa-cho, Kawasaki-shi, Kanagawa Prefecture Toshiba Electric Child Device Engineering Co., Ltd.

Claims (4)

[Claims] 1. A method of manufacturing a ceramic product, which comprises irradiating a semi-finished product, which has just been molded, with a microwave and irradiating the semi-finished product, and heating the semi-finished product to evaporate the water content to reduce the water content. 2. The temperature rise value of the microwave irradiation portion is
The method for manufacturing a ceramic product according to claim 1, which is set to 5 to 20 ° C. 3. The reduction value of the water content of the microwave-irradiated portion is set to 2% or less as compared with before irradiation.
Manufacturing method of ceramic products described in paragraph. 4. Two waveguides connected to a microwave oscillator are arranged in the oven so as to penetrate from both sides and face each other, and semi-finished products of ceramic products are easily deformed in the gaps of both waveguides. An apparatus for manufacturing a ceramic product, characterized in that it is configured to accommodate a portion and irradiate a microwave.