1. Frequent stoppages;
2. Conversion of high temperature materials and low temperature materials;
3. Screw plating off, bad plastic head;
4. After the shutdown, PP material is not used for pipe protection;
5. Production of fireproof material, PBT material, PC material, etc.;
6. Screw deformation and barrel friction;
7. The temperature control equipment is bad, and the display temperature is lower than the actual temperature.