The POE sheet line extrusion process requires that the extrusion temperature include the set temperature of the heater and the melt temperature. The heating temperature refers to the temperature provided by the external heater. Melt temperature refers to the temperature of the material between the front section of the screw and the joint. The barrel temperature distribution, from the feed zone to the die, may be flat, incremental, declining, and mixed. It mainly depends on the material point and the structure of the extruder. The temperature is set on the nose, in order to obtain better appearance and mechanical properties, and to reduce the expansion of the melt outlet, the temperature of the control body is generally lower, and the temperature of the head is higher. The high temperature of the machine head allows the material to enter the mold smoothly, but the shape stability of the extrudate is poor and the shrinkage rate is increased. If the temperature of the machine head is low, the material of the material plastic material is poor, the viscosity of the melt is large, and the pressure of the machine head rises. Although this will make the product too dense, the post-shrinkage rate is small, and the shape stability of the product is good, but the processing is difficult, the die swell is large, and the surface of the product is rough. It also causes an increase in the back pressure of the extruder, a large load on the equipment, and an increase in power consumption. The temperature of the die set, the temperature of the die and the mandrel have an influence on the surface finish of the pipe. Within a certain range, the temperature of the die and the mandrel is high, and the surface finish of the pipe is high. Generally speaking, the temperature at the exit of the die should not exceed 220 degrees, the melt temperature at the inlet of the nose should be 200 degrees, and the temperature difference between the inlet and outlet melts of the nose should not exceed 20 degrees. Because the higher temperature difference between the melt and the metal will cause a shark skin phenomenon. Excessive melt temperatures result in die buildup. However, it depends on the actual situation.
Melt temperature refers to the actual melt temperature measured at the end of the screw and is therefore a dependent variable. Mainly determined by the screw speed and barrel setting temperature. The upper limit of the melt temperature for extrusion of polyethylene pipes is generally specified to be 230 degrees. Generally, the control is preferably around 200 degrees. The upper limit of the melt temperature for extrusion of polypropylene pipes is generally 240 degrees. The melt temperature should not be too high. The degradation of the material is generally considered, and too high a temperature will make the tube difficult to shape.