Shantou film blowing machine tells you the importance of film blowing machine temperature

The quality of plastic film manufacturing depends not only on the quality of the material, but also on whether the temperature is well controlled. If the temperature of each section of the film blowing machine is controlled well, the probability of making a good film has reached 17%. Therefore, temperature control is very important. I hope everyone can understand and master these things.

Today, the editor of Shantou Shuangli will tell you about the temperature control of the film blowing machine. According to the melting theory of plastics, the extruder screw of the film blowing machine is divided into three sections: feeding section, melting section, and homogenizing section. At the end of the feeding section, when entering the melting section, according to the melting theory, its temperature should be the viscous flow temperature. The viscous flow temperature of various blown film resins are PP: 164-175 degrees Celsius, PE: 105-135 degrees Celsius, and PA: 195-210 degrees Celsius.

At the inlet of the feeding section of the film blowing machine, it is hoped that the temperature will be lower to prevent the resin from blocking the feeding port by the viscous flow of the resin. In addition, the resin is continuously compressed in the feeding section, and the air must be discharged backwards from the feeding port. Depending on the structure of the film blowing machine, although the feeding port is not electrically heated, heat is transferred through the barrel, and the temperature of the feeding port is about 50-90 degrees. In this way, the temperature of the feeding section is determined. The entrance is 50-90 degrees, and the end is equal to the melting point or viscous flow temperature, and the temperature can be set as a linear heating in this section. At the beginning of the melting section, the temperature must reach the viscous flow temperature to melt. For crystalline resins, the viscous flow temperature is equal to the melting point temperature. Then the melting layer is continuously compressed and increased, and the temperature needs to be continuously increased to make the resin molecular chain lengths vary. Polymers with different thermal motion energy are melted one after another. Therefore, after the temperature at the end of the melting section is established, it can be determined to be in this section. The other parts of the upper part are heating up linearly. In the homogenization section, it is mainly to remelt homogenization and output the melt at a constant pressure and constant temperature. The temperature in this section can be kept constant, or the temperature at the end of the melting section rises slightly (about 2-5 degrees).

For the film blowing machine, the temperature through the die section is required to be lower, but not lower than the viscous flow temperature, which is convenient for film lifting and normal film blowing. The melt must have a certain viscosity when it comes out of the die, so that it will not break or collapse. In general, it is about 10-30 degrees lower than the end of the homogenization section, and the temperature from the homogenization section to the touch point can also be regarded as an equal temperature drop.

Shantou Shuangli hopes that everyone can blow out high-quality products after purchasing the film blowing machine.