What are the reasons for the bending and deformation of extruded plates? How can they be solved?

What are the reasons for the bending and deformation of extruded plates? How can they be solved?

The main reasons are as follows:

① Improper control of the roller temperature of the calender;

② Insufficient cooling;

③ The roller temperature of the calender is too low;

④ The gap adjustment of the die lip at the machine head is unreasonable.

The solutions are as follows:

① The roller temperature of the three-roller calender should be appropriately adjusted. If the sheet curls upwards, the temperature of the lower roller should be appropriately increased, but it should not exceed that of the middle roller; if the sheet curls downwards, the temperature of the middle roller should be appropriately increased;

② The extrusion temperature and material temperature should be appropriately reduced;

③ The roller temperature of the calender should be appropriately increased;

④ The gap of the die lip should be appropriately adjusted, and the opening of the die lip is generally 10% larger than the thickness of the sheet.