JPS5859802A - Method of rapidly molding and drying pottery - 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 The present invention relates to an improved method for manufacturing ceramics, and more particularly to a method for rapidly molding and drying ceramics using a roku-face rotating shaft.

Conventional ceramic manufacturing technology involves filling a plaster mold with embryonic soil on a rotating potter's wheel, shaping it from above using a rotating molding iron, and
Using the water absorbing properties of gypsum, water is removed from the contact surface with the molded product, and the molded product is heated to a moisture content of about 13, which allows the molded product to be released from the raw material's water content of about 22 to 24% by the heating device described later. Once dried to ~14%, it is removed and further dried in a separate device.The water-absorbed plaster mold, previously dried in the sun, is now further dried continuously in the same device, ready for next use. A cycle system is used.Here, nikudo refers to a raw material that can be used for direct molding, which is made by kneading china clay in a clay kneading machine.These conventional methods involve heating the molded product held in a plaster mold after molding. The drying method will be described below with reference to (a), (b), and (c) of FIG. 1 of the accompanying drawings.

1. In the broctor drying method (a), 1 is a non-drying room maintained at a room temperature of 40 to 70°C, and 2 is a rotation that guides the endless chain 3. -7,
, 4 is appropriate for a, ni 3. A fence containing a plaster mold containing suspended moldings at intervals, such that the moldings are coffee
If the receiver is a plate, 70 fences (140 plaster molds in total) are used, with each fence in two rows. 5 is the molded product horizontally with the mold 4
6 is the position where the molded product is released from the mold; 6 is the position where the molded product is released from the mold;
The area between and 5- indicates a letter-shaped drying section, and the arrow indicates the direction of chain travel. The time required from charging the molded product to releasing it from the mold in this drying chamber is about 2 hours.

In the 2-jet drying method (O), 11 is a rotating roll that guides the endless chain 12, 13 is a fence that holds the plaster mold containing the molded product suspended on the chain 12 at appropriate intervals; The number of seeds in a row - about 50 (100 plaster molds in total) are used. 14 is a hot air duct, 15 is a jet outlet, 16
17 is the position where the molded product is loaded horizontally with the mold, 17 is the position where the molded product is released from the mold, the arrow indicates the running direction of the chain, and the period between 17 and 13 is the empty mold drying section. The hot air temperature from the hot air duct is 60°C, and the drying time is about 1 hour. A recent jet dry molding plant has about 40 molds,
- Requires drying time of approximately 20 minutes.

3. In the model diagram of the drying method (c) using high frequency (ultra-high frequency waves), 101 is a drying chamber, 102 and 103 are ultra-high-frequency oscillators, 104 is an air blowing window, 105 is a position where the molded product is charged together with the mold, Reference numeral 106 indicates the mold release position, and the arrow indicates the running direction. With this device, the number of molds is 3 to 40, the drying time is 15 to
It takes 20 minutes.

The three types of drying methods explained above each have their own drawbacks.
The main points are as follows: (1) The drying time is long, so the number of molds is large. [2)
If the drying room temperature is raised, the edges of the finished product will dry earlier, resulting in edge breakage. Regarding jet drying, (1) If the core of the jet nozzle goes out of order, lacerations will occur, so a nozzle suitable for the product is required. (2) The hot air temperature and blowout amount have very subtle effects. (3) Equipment costs and fuel costs are high. Regarding ultrashort wave drying, (1) Equipment costs are high. (2) It consumes a lot of electricity. (3) The maintenance cost of the equipment is high. (4) The mold must be rotated for uniform irradiation. Taking the disadvantages of the above three types of conventional molding and drying methods together, The main points are that it is necessary to have a large number of plaster molds, usually 40 to 120, in order to carry out continuous work with one molding machine, that the cost of drying equipment is enormous9, and that the molded product The problems include that it takes a long time to dry the mold and dry the plaster mold, and that it involves operational difficulties such as edge cutting.

Therefore, the object of the present invention is to eliminate the above-mentioned drawbacks, to make it possible to carry out continuous molding and drying operations with a small number of molds without requiring drying of the molding molds, and to significantly shorten the molding drying time. The goal is to provide a method for

The purpose of these methods is to heat a mold for making molds that has a large heat capacity and excellent heat conductivity, mold raw material liver balls on the mold, and blow air onto the heated molded product to dry it. This is achieved by the rapid molding and drying method of ceramics of the present invention.

To explain the present invention in more detail, the present invention does not use a conventional plaster mold, but instead uses a molding mold having a large heat capacity and significantly high heat conductivity. This mold is preheated to a certain high temperature in advance, and the mold is filled with liver material made by kneading china clay, and is shaped with a molding iron that rotates on a potter's wheel axis. Heat is gradually transferred from the mold, which has a large diameter and excellent heat conductivity, to the molded product via the contact surface on the lower side and the generation of water vapor begins, so air is blown from the upper side to accelerate drying.

The mold for molding used in the method of the present invention can be selected from metal molds because they can withstand high temperatures and have excellent thermal conductivity, but are not necessarily limited to metals, and may be made of materials having the above-mentioned properties. That's fine. Heat conductive as a metal.

Copper is preferable due to its non-rusting properties, but stainless steel may also be used. Ordinary iron can also be used. Since the mold has a large heat capacity, it is desirable that the ratio of the overall capacity to the molded part be large. The temperature at which the mold should be preheated is preferably higher for faster drying effects, but rapid heating of the material at the contact surface, rapid generation of water vapor, and drying are undesirable, so the upper limit of the initial mold surface preheating temperature is It seems that the temperature is about 130°C, and the lower limit is about 50°C.

However, the drying speed is a problem that subtly affects the dry finish of the molded product, and in reality, it may be possible to heat the molded product to a temperature outside this limit.

Comparing the conventional method using a plaster mold and the method using the heated mold of the present invention, the former method first molds at room temperature, so during molding, moisture in the molded product decreases due to the hygroscopicity of the plaster. Moisture is absorbed by the plaster through the contact surfaces. At the stage where molding is completed, the molded product is transferred together with the mold to the above-mentioned heating drying device, where the molded product is also dried by heating from the surface and reaches a moisture content that can be released from the mold by dehydration from the top and bottom. In the latter method, molding is performed using a preheated mold, so the heat of the mold is conducted to the molded product during molding, and drying begins earlier, and the mold reduces the moisture content of the molded product by about 10%. It has enough heat capacity to dry the mold quickly, and there is no need to dry the mold after it is released, so there is no need to prepare a large number of molds like the former). The drying time of the latter is also significantly shorter than that of the former. In addition, in the former case, drying occurs through the contact surface, so the contact surface tends to dry and adhere, making it difficult to release from the mold, whereas in the latter case, there is a slight amount of water vapor on the contact surface.
Since it remains saturated, it also has the advantage of being easier to release from the mold.

In addition, in the case of a plaster mold, the strength of the mold is not strong enough, so the moisture content of the liver ball used can only be around 22%, and if the moisture content is lower than this (for example, around 20%). There was a risk of destroying the plaster mold, but in the case of a mold, there is no risk of destruction, so the moisture content of the mold can be lowered to a level that does not affect the work, and this has an advantageous effect on shortening the drying time.

Furthermore, when using plaster molds, the edges often dry first, which is called drying, and in that case, shrinkage occurs first at the edges, which causes tearing. was. In the present invention, since drying occurs from inside the molded product, there is no need to worry about tearing of the edges as in the case of high-frequency drying, and the above-mentioned ultra-high frequency induction drying, which was conventionally carried out with large equipment and expense, can be avoided. Jet drying is no longer necessary, resulting in significant savings in fuel and electricity.

As described above, by carrying out the present invention, the drying time is greatly shortened, and only a small number of molds are required for external equipment.

It is also incomparably economical in terms of maintenance costs, and can be said to be a truly labor-saving and energy-saving method.

Figure 2 of the accompanying drawings is an explanatory side view including a partial cross section of the molding potter's wheel shaft used in the present invention, and in this figure, 201 is a mold for molding, 202 is a molded object, and 203 is for fixing the mold. The dowel, 204 is a dowel rotation axis, 205 is a molding iron, and 206 is a trowel surface rotation axis.

Next, examples of the present invention will be shown.

Example surface temperature, weight 857 to 9 preheated to 120-130°C
The iron mold is attached to the dowel shown in Fig. 2, and 144 g of liver ball material with a moisture content of 22% is filled into the mold, and the mold is shaped with a molding iron while rotating the potter's wheel spindle. Air was blown onto the mold to remove water vapor, and when the moisture content reached approximately 13%, the mold was released to make a coffee saucer.The time required from molding to mold release was approximately 3 minutes. The weight ratio converted to volume ratio was about 59 times.

[Brief explanation of the drawing]

Figure 1 is an explanatory drawing of the conventional ceramic drying method, where (a) is the broctor drying method, ((b) is the jet drying method,
→ indicates a device that implements a drying method using high frequency;
FIG. 2 is an explanatory side view including a partial sectional view of a molding potter's wheel shaft used in the method of the present invention. In this figure, 201 is an iron mold for molding, 202 is a molded object (coffee saucer), and 20
3 is a dowel for fixing the mold, 204 is a dowel rotation shaft, 205
206 is a molding iron, and 206 is a rotation axis of the iron. Figure 1 (I) Figure 2

Claims (1)

[Scope of Claims] 1) A mold for molding with a large heat capacity and excellent heat conductivity is heated, the raw material soil is molded on the mold, and air is blown onto the heated molded product. i A quick method for molding and drying ceramics that requires drying. 2) The mold for molding is made of metal, and the temperature of the mold that provides sufficient heat to quickly dry the molded product at least to the degree necessary for demolding, and the range of mold requirements in item 1. Method described. 3) The method according to claim 1, wherein the molding of the ceramic is performed by a rotating shaft.