The working temperature and pressure of the melt pump

The working temperature and pressure of the melt pump

The working temperature generally reaches 300 degrees, which can meet the requirements of transporting most plastic melts, and the melt pump with a higher temperature can reach 500 degrees. The working pressure of the melt pump is usually expressed by three parameters, that is, the maximum inlet pressure, the maximum outlet pressure and the maximum pressure difference. The maximum inlet pressure of the general melt pump is 10 - 12MPa, the maximum outlet pressure is 35MPa, and the maximum pressure difference is 25MPa. The maximum inlet pressure of Maag series high pressure melt pump is 20MPa, the maximum outlet pressure is 70MPa, and the maximum pressure difference is 50MPa.

Selection of pressure and temperature

The entrance pressure should not be too high, 3-5 MPa. High viscosity fluid requires a higher inlet pressure. Sometimes, in order to enhance the mixing effect of the extruding screw, the screw head needs higher pressure to increase the reflux, so the inlet pressure can be increased at this time. The inlet pressure can be easily obtained by adjusting the flow rate of the upstream device, such as the extruder and the melt pump. The maximum pressure difference reflects the pressure build-up capacity of the melt pump. The sum of inlet pressure and pressure difference is the outlet pressure. The outlet pressure depends on the shape of the die, the viscosity of the melt and the flow rate. The user is choosing the working temperature of the melt pump. When working pressure is met, it is not necessary to select too high grade to meet the requirement of use. Because the melt pump can work normally under high temperature and high pressure, it depends on the special material, structure and corresponding power device of the melt pump. The high temperature and pressure resistant melt pump has higher cost.