Possible causes include excessive extrusion temperature, issues with the cooling air ring (such as unstable airflow or improper positioning), an excessively high inflation ratio, problems with the mechanical transmission (like an unstable traction roller speed), problems with the raw materials (too many impurities or moisture), or interference from external airflow.
Solutions to this problem include adjusting the extrusion temperature, inspecting the cooling air ring, modifying the inflation ratio, overhauling the mechanical transmission, ensuring the quality of raw materials, and minimizing interference from external airflow.
