It is known by the high molecular physics that there are three kinds of physical states of polymers, that is, glassy state, high elastic state and viscous flow state, under certain conditions, these three kinds of physical states will be changed mutually. Solid plastic from the hopper into the human cylinder, with the screw rotation to the head direction, in the process, the physical state of the plastic is constantly changing.Plastic Single Screw Extruder

According to the changing process of three kinds of physical state of plastic in extruder and the work requirement of each part of screw rod, the screw rod of extruder is usually divided into feeding section (solid conveying area), compression section (melting zone) and homogenizing section (melt conveying area) three paragraphs. The extrusion process of plastic in extruder can be described by the basic function of each section of screw rod and the process of physical state change of plastic in extruder.Plastic Single Screw Extruder

The material from the melting section into the per capita section is a viscous fluid that has been fused completely. Forward-conveying viscous fluids under the die resistance, part of the reflux is further mixed plasticizing, and part of the quantitative pressure from the head die extrusion.Plastic Single Screw Extruder

From the above single screw extruder working principle is not disgraced, plastics in the extruder plastic, forward extrusion activities, its main power from the feeding section of the solid transport, the degree of homogenization is due to a large degree of homogenization of the structure and die resistance caused by the backflow. In the improvement of the screw mixing structure has been a lot of new structures, but it is often suitable for thermal stability of a good polymer, but not suitable for the production of PVC resin, which is not a first.Plastic Single Screw Extruder