JPS5911215A - Mold releasing method of molded product - Google Patents

Abstract

PURPOSE:To release a molded product readily without losing a mold release effect even in the repeated molding using a high temperature mold and improve the workability and utilization efficiency of the mold, by applying the mold release agent composed mainly of a mica to the mold. CONSTITUTION:After a mold release layer is at first formed by applying the mold release agent composed mainly of a mica to a mold, the mold is filled with a fluid molding material and it is molded, then an obtained molded product is released. When a molding is done using the high temperature mold, it is preferable that the life of the mold release effect of the mica layer is elongated by incorporating a silicone resin as a binder to the mold release agent. Further, in the case that the mold has a complex shape, the mold release agent composed mainly of the mica is sprayed as an aerosol.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mold release method for a molded product, and in particular, a mold release method using mica as a main component as a mold release agent used when removing the molded product from a heated mold. Regarding those using agents.

Molding materials such as plastics and rubber are
It is molded into molded products such as electronic parts and automobile parts, footwear containers, films, and sheets. In order to make these molded products, molding is often performed using a metal mold, but at this time, the molded product that is molded under pressure sticks tightly to the mold, so it is difficult to remove the molded product after molding. To make it easier, a mold release agent is applied to the mold in advance to make it easier to release the molded product from the mold. Molding using a mold includes, for example, a method in which heated and molten plastic is filled into a mold that is not heated and pressurized, and a method in which a heated mold is filled with plastic and pressure is applied.

In either case, the mold will have heat. Particularly in the case of the latter method, the mold may be heated to, for example, 500°C. Then, molding operations are repeatedly performed using such a mold.

Conventionally, silicone-based mold release agents and fluorine-based mold release agents have been used to perform molding using molds that are heated to such high temperatures. These materials are dissolved in a solvent to form a liquid, and are applied to the inner surface of a mold in the form of an aerosol by spraying.

However, since the above-mentioned mold release agent essentially has organic properties, if molding is performed repeatedly while it is applied to a high-temperature mold as described above, the quality will gradually change and the mold release effect will deteriorate. decrease. As a result, the molded product adheres to the inner surface of the mold,
When taking out the molded product, a part of the molded product may be ripped off from the mold. If this happens, not only will the molded product be defective, but if the mold is left as it is, this adhesion [-] will cause the subsequent molded product to adhere to a part of the molded product, causing part of it to peel off. If this is accumulated sequentially, it becomes . When a part of the molded product adheres to the inner surface of the mold in this way, the operation is stopped and the adhered substance is wiped off with a cloth, for example. However, if the inner surface of the mold is rubbed frequently with a cloth, it will wear out the inner surface of the mold. Molds (because they are expensive, if the number of times a month gets stuck due to wear of the molds decreases, the utilization efficiency of the molds decreases (7), which increases production costs. In an attempt to avoid the task of wiping off the kimono,
The operator should constantly monitor the mold release status of the molded product, and when it becomes difficult to release the mold, apply a mold release agent.
2 17j-fl would be great. However, this work is also complicated.3 Therefore, as described above, the present invention has been developed using a mold release agent that is conventionally used in molds that have not been heated to high temperatures, but has sufficient heat resistance. In order to improve this drawback, by applying a mold release agent containing mica as the main component to the mold, it is possible to repeatedly mold using not only a low-temperature mold but also a high-temperature mold. The present invention also provides a mold release method for molded products that does not impair the mold release effect.

Mica id, flaky mica, and powdered mica as mold release agents used in the present invention can also be used as ifFf+. These mica include hard mica, soft mica, and even strong mica such as sericite.

Since mica is an inorganic substance, it does not change in quality at temperatures that are high enough to heat the mold. However, since mica is degradable, it can easily cause delamination. Additionally, mica, especially its scale, hides the mold interface, thereby preventing molding materials such as molten resin from coming into contact with the gold. The stiffness is thought to be the reason for mica's releasability.

The mold release agent used in the present invention may be only mica as described above, but it may also contain a binder together with the mica. The binder is used to bond the mica particles supplied to the inner surface of the mold or to fix the mica particles to the inner surface of the mold.
Fi, silicone resin, and fluorine-based 0'74 fat are used, but when using incandescent resin, the temperature is 500°C.
The mold release effect of the mica layer supplied to the inner surface of a high-temperature mold can be maintained for a long time. However, if the mold is used at a relatively low temperature, thermoplastic resins or thermosetting resins other than the above resins may also be used. ! (The agent is a silicone-based flood agent (silicone oil) that is conventionally used in addition to the above.

Fluorine yarn HBf 1 (lJ agent (trade name: Guifuri (Daiki 7 Kogyo Co., Ltd.)) 1 may be included.If these are included, the mold release effect of these J'+ and the mold release effect of mica will be different. You can take advantage of the effects of both.

The above-mentioned mica, or mica and other ingredients, may be applied directly to the inner surface of the mold. When the mold has a complicated shape, it is preferable to make it into an aerosol and spray it, as this direct blowing method will cause the material to thicken if the material is not supplied. For this purpose, mica or mica and other components may be dispersed in a solvent to form a liquid, and then sprayed with a total propellant (F sub 1).

At this time, a dispersion stabilizer may be used in combination to maintain the dispersion stability of mica and other components, and a surfactant may also be used in combination to promote the dispersibility of mica.

The surface solvent is heavy and tends to evaporate after being applied to the inner surface of the mold. After the solvent evaporates, if there is only mica (bow 1), the mica particles adhere to the mold, and if there is a binder, the mica particles are fixed to the mold by the binder.At this time, the binder resin Even if it is liquid, it can be cured by the heat of the mold to eliminate stickiness.

Next, one embodiment of the present invention will be described.

Silica powder as a dispersion stabilizer and a nonionic surfactant as a dispersion promoter were added to 0 parts of mica scale (1μ to 100μ) and 90 parts of Fronsolve F113 (trade name),
Stir to mix. The mold release agent thus produced is sprayed onto the mold together with a propellant. By this injection, the inner surface of the mold heated to, for example, 500° C. is absorbed by the mold release agent, but since the solvent evaporates, a mold release layer containing mica as a main component is formed. In this state, it is filled with resin, pressurized, and left for a while to form a molded product. This molded product is easily released by the mold release layer and taken out.
2 Ru. Then, when performing the next molding operation, d, now r1i:l
d Directly fill with resin and press mold in the same manner as above. Once the #-type layer is formed in this way, the molded product can be easily removed from the mold without adhering to the mold, and the same molding operation can be repeated.

Other examples include Mica and Guifuri (described above).

[7] may be prepared by preparing a mold release agent to which is added, and spraying each of these onto the mold in the same manner as in the above example.

In any of the above examples, the number of lifetimes of the mold release layer formed using the mold release agent was increased compared to when only Dyfree was used as the mold release agent.

In addition, although the above-mentioned example was a molding example using a high-temperature mold, it goes without saying that this can also be used as a mold release agent for an injection molding method using a low-temperature mold. It can of course be used not only for breaking or kneading, but also for any place where metal (roll) and molten plastic come into contact and their release properties are required.

Further, in the above embodiments, a mold release agent was sprayed, but the mold may be immersed in the mold release agent (7).

In addition, although the above explanation was about plastics or rubber, when molding materials such as non-ferrous casting alloys such as die casting, the above-mentioned A mold release agent can be used.

As explained above, according to the present invention, for example, a mold release agent containing mica as a main component is applied to the mold to form a mica layer on the mold. It is possible to easily remove objects from molds. Particularly in the case of a molding method in which the mold is heated to a high temperature, mica's heat resistance can prolong the mold release effect for a long time. Therefore, the service life of the mold release layer applied to the mold increases, which increases workability and reduces wear on the mold surface due to wiping operations to remove resin adhered to the mold surface. Kneading allows efficient use of expensive molds.

July 13, 1981 Inventor Eitaka Itoi Bridge
Hikoji

Claims (1)

[Claims] (1) In a molding method in which the molding material is brought into a fluid state and molded using a molding mold, a mold release layer containing mica as a main component is formed on the contact surface of the molding mold with the molding material, and molding is performed. A method for releasing a molded product, which is characterized by releasing the product from the mold.