Variable-temperature circulating system and variable-temperature circulating method of injection mold

Abstract

The invention discloses a variable-temperature circulating system and a variable-temperature circulating method of an injection mold. Different mold temperatures can be obtained in different time periods in an injection molding process. According to the circulating system disclosed by the invention, high-temperature and high-heat-conductivity oil is used as a heat transfer medium; a hot oil pump and a cold oil pump which have the same flow rate are used; and different temperature requirements of an injection molding process are realized by switching cold and hot oil paths entering heat utilization equipment and controlling different oil temperatures of the injection mold injected into the heat utilization equipment.

Description

technical field [0001] The invention relates to a temperature changing system and a temperature changing method of an injection mold. Background technique [0002] Plastic injection molding products play a very important role in various industries of the national economy such as agriculture, national defense construction, transportation, instrumentation, etc., but according to the traditional injection molding process, there are inherent deficiencies, and the formed products inevitably exist. There are many defects, such as poor product precision, lack of material (cavity not filled), shrinkage, surface depression, obvious weld lines, large internal stress of the product, cracking during demoulding or use, etc. Serious problems. Most of the above-mentioned defects are caused by the injection molding process itself. For example, most polymer melts have high viscosity, and the mold is forcibly filled in the low-temperature mold cavity, and the internal stress cannot be elimina...

AI Technical Summary

Problems solved by technology

[0002] Plastic injection molding products play a very important role in various industries of the national economy such as agriculture, national defense construction, transportation, instrumentation, etc., but according to the traditional injection molding process, there are inherent deficiencies, and the formed products inevitably exist. Many defects, such as poor product precision, lack of material (cavity is not filled), shrinkage, surface depression, obvious weld lines, large internal stress of the product, cracking during demoulding or use, etc.

Most of the above-mentioned defects are caused by the injection molding process itself. For example, most polymer melts have high viscosity, and the mold is forcibly filled in the low-temperature mold cavity, and the internal stress cannot be eliminated due to rapid cooling under high shear stress.

The current conventional practice is to use a mold temperature controller to raise the mold to a certain temperature during the injection molding of the mold, which can improve the flow properties of the plastic melt and reduce the internal stress of the product, but because of the factors of the injection molding cycle, Therefore, the temperature of the mold cannot be raised too high, which restricts the further improvement of the melt fluidity and the reduction of the internal stress of the product.

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