Causes and Solutions for Warping in Extruded Sheets

What are the causes of warping deformation in extruded sheets, and how can it be resolved?

The main reasons are:

① Improper temperature control of calender rolls;

② Insufficient cooling;

The temperature of the calendering machine rollers is too low.

The die lip gap of the machine head is improperly adjusted.

Solutions include:

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

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

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

④ Adjust the die lip clearance appropriately, the die lip opening is generally 10% larger than the plate thickness.