JPS6294303A - Mold for thickening and molding powdered body and thickeningmolding method - 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 <Industrial Application Field> The present invention relates to a mold for inlay molding of inorganic powder, organic powder, or metal powder, and a molding method thereof.

<Conventional technology> In the field of powder molding, represented by casting molding,
Manufacturing complex items with reverse tapers is extremely difficult.

This is because it is extremely difficult to remove the attached body from such a shape, and cracking may be induced due to shrinkage of the attached body.

In order to solve this problem, the following methods have been conventionally used.

1) A method in which a single shaped body is divided into several parts, each part is molded separately, and later joined to integrate.

2) A method of dividing the mold itself into multiple pieces so that it can be removed.

The above two methods are used.

Examples of the former are ceramic dolls and flowers, and examples of the latter are ceramic propellers.

In any case, conventional techniques are time-consuming, and even if successful, cracks are likely to occur during demolding, and there is also the problem of cast burrs.

<Problems to be Solved by the Invention> The present invention has been made in view of the above problems, and it is possible to simultaneously mold products with complex shapes with reverse tapers in one seamless mold, and it is extremely easy to demold the molded products. The present invention aims to provide a mold for inlay molding and a method for molding the same.

<Means for Solving the Problems> As a result of intensive research into the above problems, the inventors have come to the following new knowledge. That is, 1) Powder of inorganic material, organic material or metal material,
A mold is constructed using this powder binder as a basic component, and when this binder is hardened, the mold is held firmly and the mold itself becomes porous.

2) The porous mold is capable of permeating and diffusing the liquid component of the powder mixture for ink molding, and forming an adhered body of the powder on the mold surface.

3) Little or no cracking due to shrinkage is observed in the adhered body.

4) If the bonding agent in the mold is melted or diffused after forming the bonded body, the strength of the mold will be extremely reduced, and the mold will become close to collapsing, so that it can be easily taken out without damaging the bonded body. .

The present invention has been made based on the above four new findings.

<Function> Mold retention and collapse The binder of the present invention is in a solid state at least at the temperature during inlay molding.

Typical examples include water, alcohol, other liquids, resins, wax, low-melting metals, and gases such as carbon dioxide, which change solid-liquid or solid-gas depending on humidity. If so, you can use all of them.

When these binders are in a liquid or gas state, their ability to bind powder is weak or almost non-existent, and it is almost impossible to maintain the shape of the mold itself, but once they are solidified, their binding strength increases. This has dramatically improved, and the mold is now firmly retained.

As is obvious, this causes the mold surface to have the ability to penetrate and diffuse the dispersion medium of the powder for ink molding.

After the bond is formed, if the bonding agent in the mold is melted or diffused, the mold returns to its original state with very poor bonding strength, almost collapsing, and the bond is not damaged in any way. It can be taken out without any problems.

Preventing cracks in the attached body When molding the attached body, shrinkage of the attached body during molding is an unavoidable phenomenon, and conventionally, this often causes cracks in the attached body.

This is because free shrinkage of the attached body is suppressed by the mold, but this phenomenon is not observed at all in the mold of the present invention.

Although the detailed mechanism of this phenomenon in which no cracks occur is unknown, in the mold of the present invention, at least = 4- a state is induced in which the adhered body can move without restraint to some extent at the interface with the mold. It is expected that there will be.

The blending ratio of the binder in the mold of the present invention is 1 to 98 vol.
The raw material powder used for the mold can be of any kind, as long as it does not react with the binder and dissolve or diffuse.

Ink molding in the present invention refers to a general method of molding by adding ink to a mold surface using a fluid in which molding powder is mixed or dispersed, and typical methods include slurry or slip molding. It is cast molding using.

Powders that can be applied to the molding method of the present invention range from inorganic to organic powders to metal powders, and there is no restriction at all.

<Example> Example 1 Raw material powder for mold: Blending ratio of carbon microballoon powder: 98 VO 1% Binder: Distilled water (2 VO 1%) The above balloon and distilled water were mixed at room temperature, and a rose flower shape was placed in the mixture. After burying the rubber master model, the entire body was frozen at -10℃.

The master model was removed from the mold, which was firmly held by freezing, and a cavity was formed.

The resulting mold was porous and water-absorbing.

Slurry component for cast molding. Approximately 10% alcohol is added to slurry for ceramic casting, which has a water content of approximately 30%, to lower the freezing temperature.

molding The slurry was poured into the frozen mold.

The slurry was absorbed into a mold and molded with inlay.

mold collapse After molding, the mold was thawed at room temperature.

As the water thawed, the mold's ability to retain its shape decreased, and after drying, it almost self-disintegrated.

The molded body could be removed from the mold without any damage.

The obtained molded body was completely sound and no cracks were observed.

In addition, the strength was comparable to that of ordinary plaster molded products.

Example 2 ゛Mold raw material powder Nipolyethylene (8Qvo 1%) binder:
Distilled water (20, VO 1%) After freezing the mold in the same manner as in Example 1, a cavity was formed.

Slurry ingredients Same slurry as Example 1 molding The slurry was poured into the mold.

The slurry was absorbed into a mold and molded with inlay.

After collapse molding, the mold was thawed at room temperature, and the molded product was taken out in the same manner as in Example 1.

The molded body was sound and no cracks were observed.

In addition, the strength was no different from that of ordinary plaster molded products.

Example 3 Mold raw material powder Nipolyethylene (50 VO 1%) Binder: Distilled water (50 vol'%) A cavity was formed in the same manner as in Example 1.

Slurry Components Slurry molding of alumina powder to which 28% water, 1% peptizer and 10% alcohol were added The slurry was poured into the mold.

The slurry was absorbed into the mold and molded.

After collapse molding, the mold was dried under reduced pressure to evaporate moisture (gastric bloat phenomenon). The mold lost its shape retention power as moisture diffused and collapsed, and the molded product could be easily taken out without being damaged.

The obtained molded body was sound and no cracks were observed.

Also, the strength was no different from that of plaster molded products. Example 4 template Raw material powder: Alumina (20VO1%) Binder: Distilled water (8Qvo1%) A cavity was formed in the same manner as in Example 1.

Slurry molding of nickel powder to which 28% water, 1% peptizer, and 10% alcohol were added The slurry was injected into the mold.

The slurry was absorbed into a mold and molded with inlay.

collapse A molded body was taken out in the same manner as in Example 1.

The molded product obtained was sound and intact, and no cracks were observed.

The strength was also comparable to that of ordinary plaster moldings.

Example 5 Mold raw material powder: tungsten carbide powder (,3vol.
Binder: Distilled water (97 VO 1%) A cavity was formed in the same manner as in Example 1.

Slurry Ingredients A slurry of polyethylene powder to which is added 70% water, 1% peptizer and 10% alcohol.

molding The slurry was poured into the mold.

The slurry was absorbed into a mold and molded with inlay.

collapse The molded body was taken out in the same manner as in Example 1.

The obtained molded body was sound and no cracks were observed. In addition, the strength was no different from that of ordinary plaster molded products.

Example 6 Mold raw material powder Nipolyethylene (50VO 1%) Binder: Distilled water (413VO 1%) Methanol (7VO 1%) After mixing polyethylene, methanol, and distilled water and filling a propeller-shaped rubber master model, -2
Freeze to 0℃.

The master model was removed from the frozen mold to form a cavity.

Slurry component Slurry for producing silicon nitride for reaction sintering A slurry of silicon powder containing about 28% water and 1% peptizer to which 30% alcohol is added to adjust the freezing temperature.

molding The slurry was poured into the mold.

The slurry was absorbed into the mold and molded.

collapse After molding, the mold was thawed at room temperature.

The mold loses its shape retention ability as the water thaws, causing damage to the molded product (i.e.
I was able to take it out easily without having to do anything.

The obtained molded body was sound and no cracks were observed.

In addition, the strength was comparable to that of a plaster molded product.

-" 11- In the above embodiments, polyethylene is used for organic molds, alumina and carbon are used for inorganic molds, and tungsten carbide is used for metal molds, but the present invention is not limited to these. It goes without saying that this is not the case.

Also, water or alcohol was used as a binder, but
Of course, it is not limited to this only.

<Effect of the invention> 1) It is easy to demold the molded body.

2) No cracks occur in the inner molded body.

3) No casting burrs.

4) Any shape can be made with one mold.

5) It is inexpensive.

6) High-density compacts can be changed.

Claims (1)

[Claims] 1. A mold whose basic components are a powder and a binder for the powder, and the mold is kept porous by solidifying the binder, and the binder is A mold for inlay molding of powder, which is characterized by being disintegrated by melting or aeration, 2, the mold is composed of a powder and a binder for the powder as basic components, and the binder is The mold, which is porous and retains its shape by allowing it to harden,
After injecting a powder mixture for inlay molding and performing ink molding in the porous mold, the mold is collapsed by melting or evaporating the binder in the mold, and the molded body is demolded. A method for molding powder by ink forming.