What is the impact of injection mould temperature on injection moulded parts?

Many factors affect Injection Mould cooling, such as the shape of the plastic part and the design of the parting surface, the type, temperature, and flow rate of the cooling medium, the geometric parameters and spatial arrangement of the cooling pipe, the mold material, the melt temperature, and the top requirements of the plastic part. Output temperature and mold temperature, thermal cycle interaction between plastic parts and mold, etc.

 

1. Low mold temperature can reduce the molding shrinkage of plastic parts.

 

2. Uniform mold temperature, short cooling time, and fast injection speed can reduce the warpage deformation of plastic parts.

 

3. For crystalline polymers, increasing the mold temperature can stabilize the size of the plastic part and avoid post-crystallization, but it will lead to defects such as a prolonged molding cycle and brittle plastic parts.

 

4. As the crystallinity of the crystalline polymer increases, the stress cracking resistance of the plastic decreases, so it is beneficial to lower the mold temperature. However, for high-viscosity amorphous polymers, since their cracking resistance is directly related to the internal stress of the plastic part, it is beneficial to increase the mold temperature and filling speed and reduce the replenishing time.

 

5. Increasing the mold temperature can improve the surface quality of plastic parts. Determination of mold temperature During the iplastic injection mould process, the mold temperature directly affects the filling of the plastic, the shaping of the Plastic Mould parts, the molding cycle and the quality of the plastic parts.

 

6. The mold temperature depends on the crystallinity of the plastic, the size and structure of the plastic part, performance requirements and other process conditions such as melt temperature, injection speed, injection pressure and molding cycle.

 

For amorphous polymers, the melt solidifies as the temperature decreases after being injected into the mold cavity, but no phase transition occurs. The mold temperature mainly affects the viscosity of the melt, that is, the mold filling rate. Therefore, for amorphous plastics with low and medium melt viscosity such as polystyrene, cellulose acetate, etc., using a lower mold temperature can shorten the cooling time.