When producing injection molds, there are often many factors that can affect the quality of the product. In summary, there are mainly four points:
   
1) Plastic materials
The complexity of plastic material properties determines the complexity of the injection molding process. The performance of plastic materials varies greatly due to different varieties, grades, manufacturers, and even batches. Different performance parameters may lead to completely different molding results. 
2) Injection temperature
Melt flows into the cooled cavity and dissipates heat due to thermal conduction. At the same time, heat is generated due to shear action, which may be more or less than the heat dissipated through thermal conduction, mainly depending on the injection molding conditions. 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 lower the required filling pressure. Meanwhile, the injection temperature is also limited by the thermal degradation temperature and decomposition temperature. 
3) Mold temperature
The lower the temperature of the mold, the faster the heat is dissipated due to thermal conduction, the lower the temperature of the melt, and the worse the fluidity. This phenomenon is particularly evident when using lower injection rates. 
4) Injection time
The impact of injection time on the injection molding process is manifested in three aspects:
(1) Shortening the injection time will also increase the shear strain rate in the melt, and the injection pressure required to fill the mold cavity will also need to be increased. 
(2) Shortening the injection time increases the shear strain rate in the melt. Due to the shear thinning characteristics of plastic melt, the viscosity of the melt decreases, and the injection pressure required to fill the mold cavity also needs to be reduced.