Injection mold temperature control principle

The temperature of the injection mould of plastic melt in the mold filling flow, curing finalize the design, production efficiency, and the shape of the plastic parts and dimensional accuracy has great influence.

Every plastic injection molding has a reasonable mold temperature area, make the melt flow alway full of cavity, small shrinkage and warping deformation after demoulding and size stability, mechanical properties and surface quality is high.To control the temperature of the mold, it is necessary to design temperature control system, generally adopt the method of mold cooling or heating, when necessary, two kinds of combined, used in mobile phone shell mold cooling device.

1. The necessity of temperature control

Mold temperature on the quality of plastic parts molding, molding efficiency has a great influence.In the higher temperature of mould and melt glue material has good liquidity, is advantageous to the rubber mold filling, obtaining high quality of the surface of the plastic parts surface, but can make the rubber curing time, knocking out the changeful form, for crystalline rubber, is more advantageous to the crystallization process, avoid glue storage and use of a size change;In the lower mold temperature, melt glue material is difficult to full of cavity, lead to internal stress increase, matt surface, produce the defect such as silver lines, weld marks.

Different rubber with different processing craft, and all kinds of rubber parts surface requirement and the structure is different, in order to in the most efficient time endogenous output to meet the requirements of the quality of plastic parts, which requires the mold to keep a certain temperature, the greater the stability of the die temperature, produce the plastic pieces in size shape, plastic pieces of appearance quality of the more demanding.Therefore, in addition to mould manufacturing factors, die temperature is an important factor to control plastic parts quality, mold design, mold temperature control method should be considered.

2. Mold temperature control principle

In order to ensure the most effective time of endogenous output high appearance quality requirements, size stability, small deformation of plastic parts, the design should be the understanding of the basic principles of mold temperature control.

(1) the different requirements of different rubber mold temperature.

(2) different surface quality and structure of the mould for different mold temperature, this requires targeted in the design of temperature control system.

(3) after the mold temperature is higher than before the temperature of the mold, general difference in temperature is about 2 ~ 3 DHS.

(4) there is a requirement for fire pattern mold temperature than general smooth requirements before the mold temperature is high, the current mode must be hot water or hot oil, general difference in temperature is about 40 DHS.

(5) when the actual mold temperature can't meet the requirements when the die temperature, for mould heats up, so the mold design, rubber should be considered into the mold heat can meet the requirements of die temperature.

6 by the rubber into mold heat besides consumption by means of thermal radiation and heat conduction, the vast majority of quantity of heat required by outside circulation heat transfer media out of the mold.

All landowners mould temperature should be balanced, there can be no local overheating and too cold.