How to determine the cooling time in the injection moul […]
How to determine the cooling time in the injection moulding of Chair Mould not only affects the quality of products but also affects the output and cost of products. The starting point for consideration is to transfer the necessary heat from the plastic melt injected into the mould cavity to make it become solid from the melt so as to be taken out of the mould without deformation. Therefore, correctly estimating the cooling time has become the main technological parameter that should be determined first in injection moulding.
What are the reasons that affect the cooling rate of the chair mould?
1. Mould materials and their cooling methods. When it comes to mould materials, including mould cores, cavity materials and mould frame materials have a great influence on the cooling rate. The higher the thermal conductivity of the chair mould material, the better the effect of transferring heat from plastic per unit time and the shorter the cooling time.
2. The design of plastic products. Mainly the wall thickness of plastic products. The greater the thickness of the chair mould product, the longer the cooling time.
3. Plastic selection. This refers to the measurement of the speed at which plastic conducts heat from hot places to cold places. The higher the coefficient of thermal conductivity of plastic, the better the thermal conductivity, or the lower the specific heat of plastic, the temperature is easy to change, so the heat is easy to dissipate, the thermal conductivity is better, and the required cooling time is shorter.
4. Configuration of cooling water pipes. The closer the cooling water pipe is to the mould cavity, the larger the pipe diameter and the greater the number, the better the cooling effect, the shorter the cooling time and the coolant flow rate. The greater the flow rate of cooling water, the better the effect of cooling water taking heat away by heat convection.
5. Nature of coolant. The viscosity and thermal conductivity of cooling liquid will also affect the thermal conductivity of chair mould injection. The lower the coolant viscosity, the higher the thermal conductivity coefficient, the lower the temperature, and the better the cooling effect.