Factors affecting the cooling rate of plastic products
The design of the cooling system is very important in injection molds. This is because plastic products can only be demolded after they have cooled and solidified to a certain rigidity to avoid deformation due to external forces. Since the cooling time accounts for about 70-80% of the entire molding cycle, a good cooling system design can greatly shorten the molding time and improve the efficiency of injection molding. So what are the factors that affect the cooling rate?
1. Plastic product design. In general, the cooling time is proportional to the square of the thickness of the plastic product, that is, if the thickness of the plastic product doubles, the cooling time will increase by 4 times.
2. Mold material and cooling method. The materials of the mold core, cavity, and mold base have a great impact on the cooling rate. The higher the thermal conductivity of the mold material, the faster the heat will be transferred from the plastic in unit time, and the shorter the cooling time.
3. Cooling water pipe configuration. The closer the cooling water pipe is to the cavity, the larger the diameter, and the more the number of the water pipe, the better the cooling effect.
4. Cooling water flow rate. The larger the cooling water flow rate, the better the cooling water will take away heat by convection.
5. Properties of the cooling medium. The viscosity and thermal conductivity of the cooling medium will also affect the heat transfer effect of the mold. The lower the viscosity of the cooling medium and the lower the temperature, the better the cooling effect.
6. Processing parameter settings. The higher the material temperature and mold temperature, the longer the required cooling time.
