Thickness variation

Thickness or gauge variation can result from issues with the air ring, die head, material feeding, or B.U.R. Here are common checks and actions:

Incorrect Coupling Between Air Ring and Die Head:
Ensure the air ring and die head are aligned along the central line.

Uneven Air Flow from Air Ring Exit:
Check if the air ring exit is damaged or if foreign material or dust is blocking airflow. Ensure the air entrances are uniformly distributed.

Uneven or Unstable Die Head Temperature:
Inspect the die head heater band, thermal couple, and temperature indicator to ensure they are functioning correctly.

Unstable Material Feeding:
Check the screw or hopper for material blockages, and ensure the nipple roller operates evenly. Replace the screen changer filter if polymer blockage occurs.

B.U.R. Problems:
Check if B.U.R. is too large. If necessary, replace the die head with a larger lip size to achieve the desired B.U.R.

Ambient Airflow Interference:
Eliminate direct external airflow in the working area. Use a proper ventilation system to maintain air conditioning without affecting the extrusion process.