Simply put, the complexity of the properties of plastic raw materials determines the complexity of the injection molding production process. The properties of plastic materials are due to different varieties, different injection molding production and processing conditions, different grades, and even different batches. Different injection molding performance parameters can lead to different results.
The influence of injection production time on the molding process is manifested in three aspects
(1) Due to the shear characteristics of the plastic melt, the viscosity of the melt will be reduced, and the injection pressure required to fill the cavity should be continuously reduced.
(2) should also increase the injection pressure required to fill the cavity
(3) The greater the shear heating, the less heat dissipated through heat transfer, so the higher the temperature of the melt, the lower the viscosity, the lower the injection pressure required to fill the cavity.
Injection temperature is also an issue. The melt flows into the cooled cavity and loses heat due to heat conduction. At the same time, the heat generated by shear may be more or less than that generated by heat transfer, which is caused by a variety of factors, depending mainly on the injection molding conditions. In addition, the viscosity of the melt decreases with the increase of temperature. Therefore, the higher the temperature during injection production, the lower the viscosity of the melt and the lower the required filling pressure.
Throughout the injection molding production process, different conditions have diverse effects on the injection molded product.