JPH0129124B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a forming method for producing a double-fired product having an inner wall and an outer wall.

(Conventional technology and problems) Conventionally, when forming double-fired products, the inner and outer walls were formed separately, and after the forming, the inner and outer walls were bonded together with an adhesive (mud). was.

However, this conventional method has the following problems.

(b) Since the inner and outer walls are molded separately and then glued together with adhesive (mud), the molding process requires a lot of effort and is inefficient.

(b) If the bonded parts are not aligned properly or if air is trapped in the bonded parts, this will cause cracks during drying or bisque firing, and small cracks may occur in the fabric due to handling during bonding. This often leads to large cracks during bisque firing and final firing, resulting in defective products.

(c) Since the inner wall is placed inside the outer wall and the two are glued together, it can only be applied to items whose girth is smaller than the girth of the mouth, such as dishes and potted plants.
It was impossible to mold so-called bags whose waist circumference was larger than their mouth circumference.

(Means for Solving the Problems) The present invention was invented in order to solve the conventional problems, and its purpose is to:
The inner and outer walls can be formed in a series of processes,
There is no need to use adhesives (mud) that can cause cracks, and there is no need to touch the fabric during molding.
Furthermore, it is an object of the present invention to provide a method for forming double-glazed items such as dishes and bags that can be easily formed regardless of the shape. A sludge casting molding method using
An inner wall forming process in which a mouth side casting spout mold is set on the upper surface of the inner mold having a split structure, and in this state, slurry is poured from the mouth side casting spout mold to form the inner wall, and next, the inner wall is held from the inside side. an inner mold demolding step of removing the inner mold after setting a padding mold to the mouth side casting mouth mold, and then covering the outer circumferential surface of the inner wall with a wax film except for the connection part with the outer wall. A wax film coating step: Next, an outer mold with a split structure is set on the bottom surface of the mouth side mold, and then slurry is poured into the outer mold from the bottom side mold, and the inner wall and the inner wall are formed at the connection part. We decided to adopt a configuration that includes an outer wall forming process in which the outer walls are formed in a continuous state, and then a full demolding process in which all the molds are removed.

(Function) Therefore, the most important feature of the molding method of the present invention is that the inner wall is first molded, and the outer circumferential surface of the inner wall is coated with a wax film except for the connection part with the outer wall. When forming the outer wall, the slurry is repelled from the part covered with the wax film, and the outer wall and the inner wall are integrally connected at the connection part with the outer wall not covered with the wax film, and At this time, the pressure on the inner wall due to the pouring of the slurry is absorbed by the wax membrane, so that the inner wall does not collapse. Incidentally, the wax film will be burned at the time of bisque firing.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. In this embodiment, as shown in FIG. 6, a double-sided small bowl A having a bottom wall is an example of a double-sided pottery product. The double small bowl A of this embodiment has an inner wall 1 and an outer wall 2.
and a bottom wall 3, and the inner wall 1 and the outer wall 2 are formed in a so-called bag shape with the waist circumference larger in diameter than the mouth circumference, and a space 4 is formed between the inner walls 1 and 2. is formed, and the inner wall 1 and the outer wall 2 are integrally connected with the mouth edge as the connecting part 5, and the outer wall 2 and the bottom wall 3 are integrally connected with the bottom edge as the connecting part, forming a raised bottom structure. ing.

Next, a method of forming the double small bowl A will be explained with reference to FIGS. 1 to 5.

The molding method of this example uses a slurry with a moisture content of 28%, which is a mixture of clay, silica, feldspar, etc., and water. After casting this into a plaster mold, it is left to stand for several minutes (approximately 8 to 10 minutes), and the slurry is mixed with water. After the slurry is absorbed into the plaster mold and solidified to a certain thickness around the mold, a slurry casting method is adopted in which the slurry is drained. Mold removal process (Figure 2), wax film coating process (Figure 3), outer wall forming process (Figure 4), bottom wall forming process (Figure 5), complete mold removal process,
The molding method is to mold in the following order.

In the inner wall forming process, first, the left and right molds 11, which are divided vertically into two, are assembled to assemble the inner mold 12, and a mouth side casting mouth mold (hereinafter referred to as "mouth side mouth mold") is placed on the upper surface of the inner mold 12. '') Mark 13 Part 1
Set it in the fitted state in step 4 (Fig. 1-A),
In this state, slurry B is injected from the mouth side mold 13 to the mouth side mouth mold 13 to the fullest extent (Fig. 1-B), and the slurry B is poured from the inner circumferential surface of the inner mold 12 into the mouth side mold 13 by the slurry casting method. A continuous wall of the inner wall 1 and the extended tapered wall 1a is formed with a thickness of about 2 mm over the inner circumferential surface of the wall 13 (FIG. 1-c). In addition, the left and right molds 11 of the inner mold 12,
11 are properly mated by fitting irregularities (not shown) formed on the mating surfaces, and the mating state is maintained by a rubber band 15, and the inner mold 12 and the mouth side mouth mold 13 are Positioning unevenness (not shown) is also formed between the two. Further, grooves 16 are formed in the circumferential direction on the mouth edge of the inner mold 12,
This is the outer wall forming process that will be described later, and the outer wall 2 and inner wall 1 are
This is a means to strengthen the connection with the government.

Next, in an inner mold demolding step, the inner mold 12 is demolded, and in this case, a padding mold 17 is used. The fitting mold 17 includes a pedestal portion 18 that faces the upper surface of the mouth side mouth mold 13, and a wall holding portion 19 that fits into the inside of the inner mold 12, and the wall holding portion 19 has an extended tapered wall. A tapered surface 19a that faces the inner surface of 1a and holds the extended tapered wall 1a between it and the mouth mold 13 is formed on the proximal end side, and a straight surface 19b is formed at the distal end from the tapered surface 19a. , is formed so as to hold the mouth edge of the inner wall 1 from the inner side at the base end portion of the straight surface 19b. Incidentally, a positioning means such as a matching mark is also provided between the contact mold 17 and the mouth side mouth mold 13. Then, after setting the above-mentioned padding mold 17 on the mouth side mouth mold 13, turn it upside down (Fig. 2-A), and in this state, remove the left and right molds 11, 11 of the inner mold 12, and remove the left and right molds 11, 11 of the inner mold 12. Type 1
2 (Fig. 2-B).

Next, in the wax film coating process, a wax film 20 is formed on the outer peripheral surface of the inner wall 1 exposed in the inner mold demolding process. The inner mold 12 is demolded and immersed in the wax 21 for about 15 seconds with the inner wall 1 held by the mouth mold 13 and the stopper mold 17 facing downward, and then pulled out to solidify the wax 21. In this case, it will be immersed to the position shown by dotted line M so as not to form a wax film 20 on the edge of the mouth which will be the connection part 5 with the outer wall 2 (FIG. 3).

After the wax film 20 is formed on the outer peripheral surface of the inner wall 1 except for the connection part 5 with the outer wall 2 as described above, the outer wall 2 is formed in the next outer wall forming process. In this outer wall forming process, first, the outer mold 23 is assembled on the bottom surface of the mouth side mouth mold 13 described above in such a manner that the left and right molds 22, 22, which are vertically divided into two, are brought into contact with each other. On the top surface of the bottom casting spout mold (hereinafter referred to as "bottom spout mold") 24
In this state, the slurry B is injected from the bottom mouth mold 24, and the outer wall 2 is formed with a thickness of about 3 mm by the slurry casting method. (Figure 4-B).
In this case as well, the left and right molds 2 of the outer mold 23
2 and 22 are properly mated by fitting the unevenness formed on the mating surfaces, and the mating state is maintained by the rubber band 26, and between the outer mold 23 and the bottom mouth mold 24. Also, unevenness for positioning is formed. In this outer wall forming step, since the slurry B is injected from above the inner wall 1 covered with the wax film 20, pressure due to the slurry B acts on the inner wall 1, but the outer peripheral surface of the inner wall 1 Except for the connection part 5, the connection part 5 is protected by the wax film 20, and the connection part 5 which is not covered with the wax film 20 is held from the inside surface by the patch mold 17, so that it can withstand the pressure caused by the slurry B sufficiently. In addition, during mud removal casting molding, the slurry B is repelled by the wax film 20 except for the connecting portion 5, and only the connecting portion blends in with the slurry B and becomes integrated. At this connecting portion 5, the inner wall 1 and the outer wall 2 can be integrally connected.

After forming the outer wall 2 as described above, the bottom wall 3 is formed next in the bottom wall forming process. First, the extension wall 2a formed on the inner surface of the bottom side mouth mold 24 is cut out, and Remove the mouth mold 24 and set the bottom mold 25 on the outer mold 23 (Fig. 5-
stomach). Then, by turning the whole thing upside down, the slurry B remaining when forming the outer wall 2 will flow onto the bottom mold 25, and the bottom wall 3 will be formed with the bottom edge connected to the outer wall 2. (Figure 5-b). in this case,
If there is not a small amount of slurry B remaining, an appropriate amount of slurry is added.Also, when the bottom wall 3 is formed as in this embodiment, the space 4 is sealed, and the internal air is removed during the subsequent bisque firing and main firing processes. Therefore, the straw 26 is passed through the bottom mold 25 and an air vent hole 27 is formed in the bottom wall 3. After molding the inner wall 1, outer wall 2, and bottom wall 3 in this manner, the bottom mold 25, outer mold 23, opening mold 17, and opening mold 13 are each removed in a complete demolding process. The molded product is taken out, and at this time, the straw 26 is removed before the bottom mold 25 is demolded to prevent the air vent hole 27 from deforming.

Finally, the extended tapered wall 1a formed in the inner wall forming process is cut out, and the entire structure is finished.

The entire demolding process described above constitutes a molding process, and the next step is to dry the molded product and then subject it to bisque firing, but at this time the wax film 20 described above burns and disappears. Next, the unglazed dough is glazed and fired to form a final firing to produce the small bowl A as a product. The inner surface of the space 4 may also be glazed.

Although one embodiment of the present invention has been described above using the plan view, the specific configuration of the present invention is not limited to the above-described embodiment.

For example, in the examples, the case of forming a double-sided small bowl for bags was used as an example, but the molding method of the present invention can be particularly effectively applied to bags, but it can also be applied to double-glazed items other than bags. It can be applied to everything. Further, although a bottom wall forming step was provided in the embodiment, this bottom wall forming step can of course be omitted for products that do not require a bottom wall.

Further, as long as the inner mold and the outer mold have a split mold structure that can be removed, there is no limit to the number of divisions, but it is preferable that the number of divisions be as small as possible.

For reference, it is also possible to use a peeling agent such as vinyl instead of a wax film that covers the outer circumferential surface of the inner wall, but it is best to use wax from above to maintain the shape of the inner wall. preferable.

(Effects of the Invention) As explained above, according to the present invention, a double-fired product can be formed efficiently through a series of steps, there is no need to use any adhesive, and the intermediate molded product can be formed by hand. Since there is no need to handle it, there are no factors that can cause cracks, and it not only becomes possible to mold bags, which was previously considered impossible, but it can also be applied to baked goods other than bags, making it possible to double the scope of application. This applies to all types of pottery.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram of the inner wall molding process, Figure 2 is an explanatory diagram of the inner mold removal process, Figure 3 is an explanatory diagram of the wax coating process, Figure 4 is an explanatory diagram of the outer wall molding process, and Figure 5 is an explanatory diagram of the outer wall molding process. 6 is an explanatory diagram of the bottom wall forming process, and FIG. 6 is a sectional view of a double-fired product as a product example. A: Double small bowl, B: Slime, 1: Inner wall, 2: Outer wall, 5: Connection part, 12: Inner mold, 13: Mouth side mold, 17: Relief mold, 20: Wax film, 23: Outer mold , 24: Bottom casting mouth type.

Claims (1)

[Claims] 1. A slurry casting molding method using a plaster mold, in which a mouth-side pouring spout mold is set on the upper surface of an inner mold having a split structure, and in this state, slurry is poured from the mouth-side spout mold. an inner wall molding step in which the inner wall is molded by inserting the inner wall into the mold; and an inner mold demolding step in which the inner mold is removed after a supporting mold for holding the inner wall from the inner side is set in the mouth side casting mouth mold. Next, a wax film coating step of coating the outer circumferential surface of the inner wall with a wax film except for the connection part with the outer wall, and then, after setting an outer mold with a split structure on the bottom surface of the mouth side casting spout mold. an outer wall forming step in which slurry is poured into the outer mold from the bottom casting spout mold to form the outer wall so as to be continuous with the inner wall at the connecting portion; and then a complete demolding step in which all the molds are removed from the mold. , A method for forming a double-fired product, characterized by having the following steps.