JPH0729315B2 - Manufacturing method of hollow body with internal pattern - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a hollow body having an internal pattern used for decoration, a display container, and the like.

[Conventional technology]

In the conventional method for producing a molded body having a three-dimensional pattern inside, the three-dimensional pattern itself that forms the pattern has to be embedded in the molded body. That is, a product having a pattern formed in the internal hollow space has not been obtained.

[Problems to be solved by the invention]

As described above, conventionally, a method for manufacturing a hollow body having a pattern formed in the inner hollow space has not been developed, and this development is strongly desired.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a method capable of manufacturing a hollow body having a pattern inside thereof without complicated steps.

[Means for solving problems]

In order to achieve the above object, the method for producing a hollow body with an internal pattern according to the present invention is such that an internal mold formed of a soluble substance is provided in an internal molding space of a mold at a predetermined distance from an inner wall surface of the internal molding space. While maintaining the state, the molding material is poured into the molding space inside the mold to be solidified to form a molded body, and then the internal mold inside the molded body is melted to form the inside of the molded body. A hollow space consisting of a trace of dissolution of the mold is formed, and gypsum or gelatin is used as the soluble substance.

That is, the present inventor, in the molding method by the mold,
As a result of conducting a series of studies to form a pattern in the internal hollow space, an internal mold made of a soluble substance (gypsum, gelatin) was inserted into the internal molding space of the mold, and in that state After injecting and solidifying the molding material into the inner mold, if the inner mold is melted by a method according to the material, the space formed along the shape of the inner mold of the melting trace causes the outer shape of the inner mold to become a hollow wall The present invention has been reached by finding that an internal hollow pattern faithfully transferred is formed.

The soluble substance forming the inner mold of the present invention is usually classified into the following two types according to the molding material for molding the hollow body, which is injected into the inner molding space of the mold.

When plastic is used as the molding material for forming the hollow body, gypsum (CaSO ₄ ) and gelatin are generally used as the soluble substance. When the molding material is an inorganic material such as glass, gypsum is generally used.

A hollow body with an internal pattern can be produced using such a raw material, for example, as follows. That is, using a mold for forming an internal mold in advance, an internal mold made of a soluble substance having a desired pattern is formed, and a molding material injection hole or the like is formed when assembling the mold for splitting a hollow body into halves. Hang through. Next, in that state, the molding material is injected into the mold through the injection hole and solidified. After solidification, a hole reaching the soluble substance inside is opened from the injection hole, and the internal mold, which is the soluble substance, is removed by melting or the like by a method depending on the material, and the removal trace is made into a hollow pattern. In the case of removing the soluble substance, if the molding material is solidified and formed into a molded body, there is no problem either before or after taking out the molded body from the mold.

A method of removing the internal mold made of the soluble substance from the molded body by melting or the like will be described. First, when gelatin is used as a soluble substance, hot water is put into a syringe equipped with a small-diameter injection needle, a hole reaching the soluble substance from a molding material injection hole is opened, and hot water is injected. The dissolved gelatin solution flows backward from the outer circumference of the needle and the solution elutes. When gypsum is used as the soluble substance, there are two methods. First, in the case of using gypsum calcined by heating to 120 ° C or higher, boiling water is treated with sodium thiosulfate (Na
₂ S ₂ O ₃ ) Dissolve gypsum instead of the aqueous solution. As another method, there is a method in which gypsum is finely crushed using at least one of ultrasonic waves and high frequencies, and a hole reaching the soluble substance is formed through a molding material injection hole and gypsum powder is taken out through the hole. Next, the elution holes from which the soluble substance has been taken out are filled by, for example, discharging a molding material having the same quality as the molding material from an injection needle.

The hollow body with an internal pattern thus obtained is usually
It is a transparent product, and the hollow pattern inside can be clearly seen through the transparent part, so that it can be used for various decorations and displays.

〔The invention's effect〕

This invention is to produce a hollow body with an internal pattern as described above, and by using gypsum or gelatin as a soluble substance which is a material for forming an internal mold, a wide range of materials such as glass and transparent synthetic resin can be obtained. A hollow body molding material can be appropriately selected, and an internal pattern composed of a hollow space can be easily formed inside a transparent molded body. By changing the outer shape and outer peripheral surface pattern of the internal mold made of a soluble substance, these shape patterns can be faithfully transferred to the hollow wall surface of the above-mentioned hollow space so that a wide variety of internal hollow patterns can be formed. Become. Then, as an application thereof, it is possible to provide a product having a rich decorative property by injecting a decorative solution into the inner hollow pattern. Also, for example,
When using gelatin as a forming material in the internal mold,
Since it can be regenerated after use, it can be used repeatedly and a cost reduction can be realized. Further, gypsum and gelatin used as soluble substances are dissolved using an aqueous solution of sodium thiosulfate and hot water, respectively, so that it is not necessary to use a solvent, and handling is easy and safe.

Next, the present invention will be described based on examples.

Example 1 A golf ball was prepared by using a golf ball, the periphery of which was solidified with gypsum to form left and right halved gypsum molds for forming an internal mold, and a gelatin solution was enclosed in the gypsum mold. Next, as shown in FIG. 1, the internal mold 3 was placed in the internal space of the column-forming mold 1 divided into upper and lower parts and hung with a thread. In that state, the transparent synthetic resin molding material was poured from the molding material injection hole 2 and waited for several hours for solidification. Then, the mold 1 was opened to take out the columnar shaped body, and as shown in FIG. 2, elution holes 4 were formed to reach the golf ball-shaped inner die 3. Then, a small-diameter injection needle is inserted into the elution hole 4, hot water is injected to dissolve the gelatin, and the dissolved gelatin solution is poured out from the gap between the outer periphery of the injection needle and the elution hole 4, and the golf ball is left in the outflow trace. -Shaped hollow space (pattern space) was formed. Next, the columnar shaped body was laid down sideways, and a plastic resin of the same quality as the molding material was poured into only the elution hole 4 by a small-diameter injection needle to fill the elution hole 4. In this way, a hollow body having a golf ball-shaped pattern space formed therein was obtained.

Example 2 A spherical internal mold made of gypsum (CaSO ₄ ) was prepared. Next, the internal mold was inserted and suspended in the internal space of the cube-molding mold. Then, the transparent synthetic resin molding material was poured from the molding material injection hole of the mold and left for several hours to wait for solidification. Next, the transparent cubic molded body was taken out from the mold, and elution holes having a relatively large diameter were formed so that it could function as a flower vase. An injection needle was inserted into this elution hole, sodium thiosulfate (Na ₂ S ₂ O ₃ ) was injected, and the gypsum was dissolved. The dissolved gypsum solution was poured out through the elution holes. In this way, a transparent container as a vase, a cosmetic container, and a food container as shown in FIG. 3 was obtained.

Example 3 The golf ball pattern internal mold was replaced with a bolt pattern. Otherwise in the same manner as in Example 1, a hollow body for display having a bolt pattern inside was obtained. This is shown in FIG.

[Example 4] An internal mold was prepared in which a coating film was applied to the surface of a freezer made of gelatin. Otherwise, in the same manner as in Example 1,
A hollow body for display having a daruma pattern inside was obtained. At this time, the paint film was transferred to the wall of the pattern space of the molded body by the heat of the injection molding material, and it looked as if the daruma was actually embedded. This is shown in FIG.

In the above description, a transparent hollow body is manufactured using a transparent molding material, but an opaque molding material is used to increase the internal pattern space so that it can be used, for example, as a reinforcing material filling space. May be.

[Brief description of drawings]

FIG. 1 is a layout view of an internal mold formed of a soluble substance in a space for internal molding of a mold, FIG. 2 is a drawing of formation of elution holes in a cylindrical molded body, and FIGS. 3, 4, and 5 are It is explanatory drawing of another Example. 1 ... Mold, 2 ... Molding material injection hole, 3 ... Internal mold,
4 ... Elution hole

Claims (2)

[Claims] 1. An internal mold formed of a soluble substance is inserted into an internal molding space of a mold with a predetermined distance from an inner wall surface of the internal molding space, and in that condition, the inside of the mold is molded. Injecting a molding material into the molding space to solidify it to form a molded body, and then melt the internal mold inside the molded body to form a hollow space consisting of melting traces of the internal mold inside the molded body. A method for producing a body, which is characterized in that gypsum or gelatin is used as the soluble substance, and a hollow body with an internal pattern is produced. 2. The method for producing a hollow body with an internal pattern according to claim 1, wherein the molding material is transparent.