The extruder screw of the blown film machine is divided into three sections: feeding section, melting section, and homogenization section. Next, let us provide you with a detailed understanding.
1. Temperature requirements for the feeding section: At the inlet of the feeding section, it is hoped that the temperature can be lower to avoid resin sticking to the inlet. In addition, the resin in the feeding section will be tightened from time to time, and air will be discharged backwards from the feeding port. According to the different structures of the equipment, although the electric heating does not stop at the feed inlet, the temperature at the feed inlet is about 50-90 degrees Celsius after heat transfer from the cylinder. In this way, the temperature of the feeding section is determined. The inlet temperature is 50-90 degrees, and the end is equal to the melting point or viscous flow temperature. In this section, temperature can be determined as a proportional linear temperature rise.
2. Temperature requirements for the melting section: At the beginning of the melting section, the temperature should reach the viscosity flow temperature before melting. For crystalline resins, the viscosity flow temperature is equal to the melting point temperature. Then continuously tighten and increase the melting layer, constantly raise the temperature, so that the length of the resin molecular chains is different, causing polymers with different thermal transport energies to melt successively. Therefore, after determining the temperature at the end of the melting section, it can be determined that the other parts of the section are linearly heated.