JPH09109122A - Compression molding method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for compression molding which makes it possible not to leave the part of the molding in the cavity by adhering or not to deform the molding and has the excellent releasability from the cavity. SOLUTION: The method for compression molding comprises the steps of supplying a molding material to the cavity 14 formed of the upper and lower molds 11, 12 of a mold 10, previously coating the surfaces of the molds 11, 22 for forming the cavity 14 with mold release material in the case of compression molding the molding before baking, then supplying the material to the cavity 14, and compression molding the molding.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a compression molding method for molding a molded body of a molding material such as ceramics before firing.

[0002]

2. Description of the Related Art Conventionally, in compression molding using a press or the like, a molding material used for molding a molded body before firing, such as a ceramic material, is made of an organic substance for shaping and releasing. A so-called binder is compounded. The molding material mixed with this binder is supplied to the cavity formed by the upper mold and the lower mold, and compression molding of the molded body is performed. Further, the binder is completely combusted, vaporized and removed in the firing step of the molded body, so that a final molded body of only the ceramic material is obtained.

On the other hand, in the compression molding of a cement molded product by a press, for example, in Japanese Patent Laid-Open No. 3-112607, sand particles are uniformly sprayed on the surface of the shaped object before pressing, so that the surface of the shaped object is compressed. It has been proposed that direct contact with the mold surface can be avoided and that the shaped body can be easily separated from the mold without using a mold release agent.

[0004]

However, in the compression molding of the ceramic material as described above, since the compounded molding material has a viscosity and is compressed, the cavities of the upper die and the lower die are compressed. It is easy to stick to the surface, and reliable release is difficult only by the effect of the binder, and there is a problem that a part of the molded product remains in the cavity and the molded product is deformed. On the other hand, the method of evenly dispersing the sand particles on the surface of the shaped body before pressing as described in JP-A-3-112607 is effective in molding the cement molded body, but molding of ceramic or the like. It cannot be applied in the molding of materials.

The present invention has been made in view of the above-mentioned problems, and an object thereof is to solve these problems, and to perform compression molding using a ceramic material in the cavity. It is intended to provide a compression molding method which is excellent in mold releasability from a cavity without causing a part of a molded body to be attached and left on or to be deformed.

[0006]

According to the compression molding method of the present invention as set forth in claim 1, a molding material is supplied to a cavity formed by an upper mold and a lower mold of a molding die to form a molding before firing. When performing compression molding for molding, in advance, a mold release agent is applied to the surfaces of the upper mold and the lower mold that form the cavity,
After that, a molding material is supplied to the cavity to perform compression molding of the molded body.

In the compression molding method of the present invention as set forth in claim 2, the mold is released from the surfaces of the upper mold and the lower mold of the cavity forming the pouring port of the crucible-shaped molded product having the pouring port projecting laterally from the main body. A method for compression molding, which comprises applying an agent and then supplying a molding material to the cavity to perform compression molding of the molded body.

Boron nitride (BN) is preferably used as a release agent applied to the surfaces of the upper mold and the lower mold, and a very small amount may be uniformly applied to the surfaces of the upper mold and the lower mold. . Further, boron nitride (BN) can be applied to the surface of the cavity by a powder or spray method.

[0009]

In the compression molding method of the present invention as set forth in claim 1, a mold release agent is applied to the surfaces of the upper and lower molds for forming the cavity, and then the molding material is supplied to the cavity, Since the molded product is compressed and molded, part of the molded product does not remain attached to the cavity, and the molded product is not deformed or damaged, and the mold releasability from the cavity is excellent. Compression molding can be performed.

Further, in the compression molding method of the present invention as defined in claim 2, the surfaces of the upper mold and the lower mold of the cavity forming the pouring port of the crucible-shaped molded product having the pouring port projecting laterally from the main body are formed. Since the mold release agent is applied, the mold releasability of the above-mentioned pouring spout is improved because the mold releasability is poor and a part of the molded product is apt to adhere to the mold surface to cause a defective portion. Compression molding has become possible.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing an example of a molding die used in the compression molding method of the present invention. In FIG. 1, the molding die 10 is set and used by a pressing machine or the like, and is configured by an upper die 11, a lower die 12, and a pressing die 13. The pressing die 13 is capable of penetrating the bottom surface of the lower die 12 and being slidable in the vertical direction, and is for pushing up the molded body upward.

Accordingly, the upper die 11 is lowered and the forming die 10
With the cavity closed, the cavity 14 for molding the container-shaped molded body has the upper mold 11, the lower mold 12, and the pressing mold 1.
3 and 3.

In the present invention, as shown in FIG. 1, before the molding material is charged into the lower mold 12, boron nitride (BN), which is a powdery mold release agent, is preliminarily added to the upper mold 11 and the lower mold 11. It is applied very thinly on the surfaces of the mold 12 and the cavity 14 of the pressing mold 13. Subsequently, the molding material is supplied into the lower mold 12, and the upper mold 11 is operated to move down to move the lower mold 12
The molding material supplied therein is shaped while being compressed.

When the molding process is completed, a molded body 15 is molded in the cavity 14, as shown in FIG. Then, when the process of opening the mold is started, first, the upper mold 11
Is activated and rises. When the upper die 11 completes its ascent, the pressing die 13 ascends due to the operation of the hydraulic mechanism or the like, pressing the bottom surface 15a of the compact 15 to separate the compact 15 from the cavity surface of the lower mold 12. .

At this time, in the conventional compression molding method,
Due to the adhesion of the molded body to the surface of the lower mold 12, the molded body 15
There is a crack in the periphery 15b of the bottom surface 15a due to internal strain, a crack occurs in the lower portion 15d at the tip of the upper end spout 15c, and further, the upper end spout is deformed due to protrusion. Although there was a problem, in the compression molding method of the present invention, by applying the mold release agent to the surfaces of the upper mold 11, the lower mold 12, and the pressing mold 13, the mold releasability of the molded body 15 is significantly increased. It is improved, the above problems are solved, a part of the molded body adheres and remains in the cavity,
It is possible to perform compression molding with excellent mold releasability from the cavity without deforming the molded body.

(Embodiment) Using the mold 10 shown in FIG.
As a molding material, about 50% of barium titanate, about 50% of zircon cordierite, and a small amount of other compounding materials were added, and compression molding was performed using a ceramic material kneaded using an oil-based material as a binder. Upper mold 11 and lower mold 1
2, and the cavity surface of the pressing die 13 was coated with boron nitride (BN), which is a release agent, as described above.

As a result, the bottom surface and the corners of the molded body 15, and further, the spout at the upper end can be smoothly released, and molding with good quality can be performed without causing cracking, chipping, or deformation as in the conventional case. I got a body.

[0018]

According to the compression molding method of the present invention as set forth in claim 1, a mold release agent is applied to the surfaces of the upper mold and the lower mold for forming the cavity, and then the molding material is supplied to the cavity. Since I tried to perform compression molding of the molded body,
It is possible to perform compression molding with excellent releasability of the molded body from the cavity without part of the molded body remaining attached to the inside of the cavity or deformation or loss of the molded body.

Further, in the compression molding method of the present invention as set forth in claim 2, the surfaces of the upper mold and the lower mold of the cavity forming the pouring port of the crucible-shaped molded product having the pouring port projecting laterally from the main body are formed. Since the mold release agent is applied, the mold releasability of the above-mentioned pouring spout is improved because the mold releasability is poor and a part of the molded product is apt to adhere to the mold surface to cause a defective portion. Compression molding has become possible. Therefore, it is suitable as a compression molding method.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a molding die used in a compression molding method of the present invention.

FIG. 2 is a cross-sectional view showing a mode of compression molding by a molding die.

[Explanation of symbols]

 10 Mold 11 Upper Mold 12 Lower Mold 13 Push Mold 14 Cavity 15 Molded Body 15a Bottom 15b Surround 15c Spout 15d Lower

Claims (2)

[Claims] 1. An upper mold for forming the cavity in advance when a molding material is supplied to a cavity formed by an upper mold and a lower mold of the mold to perform compression molding for molding a molded body before firing. Apply a release agent to the surface of the lower mold, and after that,
A compression molding method comprising supplying a molding material to a cavity to perform compression molding of a molded body. 2. A mold release agent is applied to the surfaces of the upper mold and the lower mold of the cavity forming the pouring port of the crucible-shaped molded product having the pouring port projecting laterally from the main body, and then the molding material is applied to the cavity. Is supplied to perform compression molding of a molded body.