1). Plastic materials The complexity of injection moldi […]
1). Plastic materials
The complexity of injection molding process is determined by the complexity of plastic material. However, the performance of plastic materials varies greatly because of different materials, different brands, different manufacturers and even batches of production. Different material parameters may lead to completely different product molding results.
2). Injection temperature
The melt flows into the cooling injection mold cavity, resulting in heat loss due to heat conduction. At the same time, due to the shear action, heat is generated, and this part of heat may be more or less than the heat transfer loss, which is mainly dependent on the injection molding conditions of the automobile parts. The viscosity of the melt decreases with increasing temperature. In this way, the higher the injection temperature, the lower the viscosity of the melt, and the less filling pressure required. At the same time, the injection temperature is also limited by thermal degradation temperature and decomposition temperature.
3). Mold temperature
The lower the temperature of injection mold, the faster the heat dissipation due to heat conduction, the lower the temperature of the melt and the worse the fluidity. This is especially true when the rate of injection is low.
4). Injection time
The influence of injection time on injection molding process is shown in three aspects:
(1) to shorten the injection time, the shear strain rate in the melt will also increase, and the injection pressure needed to fill the cavity needs to be improved.
(2) shorten the injection time, melt of shear strain rate increase, due to the shear thinned characteristics of plastic melt, melt viscosity, in order to full of injection mold cavity injection pressure is needed to reduce.