The PVC pelletizing production line feeds the uniformly mixed raw materials into the barrel of the extruder through the hopper according to the requirements of the plastic product formula. With the rotation of the screw, the raw materials are forced to the machine head by the auger, and the raw materials are squeezed, sheared, and stirred.

The friction between the barrel and screw and the friction between the raw material molecules will generate a certain amount of heat when it acts. Therefore, the temperature of the raw material in the barrel is getting higher and higher, and its physical state gradually changes to a highly elastic state, and finally becomes viscous. Fluid state until completely plastic. In this whole process, the extruder part plays a key role, and its main technical point is in the plastic extruder part.

A1. The heating temperature depends on the softening point or melting temperature of the carrier resin. The higher the softening point or melting temperature of the carrier resin, the higher the heating temperature. Generally, it should be about 5°C higher than the melting temperature of the resin. In general, the temperature in zone two should be the highest temperature for granulation, zone one is about 10℃ lower than zone two, and zone three and zone four are basically the same as zone two, starting from zone five until the machine head presses 5~10°C The gradient gradually decreases.

A2. The rotation speed of the main engine is determined by the output. The higher the rotation speed of the main engine, the greater the output. The speed of the main machine should also match the speed of the feeder and the speed of the pelletizer, otherwise there will be abnormal phenomena such as feeding off or too large or too small particles.

(1) When the feed screw speed is too small, the material in the main engine screw does not completely fill the screw gap. In the main engine screw, the material is relatively small and the load is small. At this time, the material in the screw shows a low pressure shear. Can not achieve a good dispersion effect.

(2) When the speed of the feeding screw is too high, the material transferred by the feeding screw to the screw gap of the main engine is always too late to be sent out by the screw of the main engine. Generally, it is appropriate to control the main engine speed at 60~70% of the maximum speed. , And too low host speed should be regarded as abnormal production, which may reduce the service life of the machine and other problems.

(3) The use of water pump and vacuum pump is a device used to adjust the temperature of the screw. As long as the temperature adjustment of each zone is reasonable, the water pump can be used. Vacuum pump is a device used to remove low volatile components, generally used for grafting reaction or starch filling masterbatch production.