The main areas to check are temperature, pressure, cleanliness, film compatibility, and mechanical condition. Work through them in order. Most center seal problems can be corrected after these adjustments.
Temperature
If the seal is weak, check whether low temperature is preventing proper bonding. Raise the center seal heating bar in steps into the 120-150°C range for PE film. Test seal strength after each change. Do not go so high that the film burns through.
Pressure
If center seal roller pressure is too low, the seal line may look spotty or incomplete. Increase pressure slowly with the adjustment knob or air pressure valve. Watch how tightly the roller presses the film. Stop when the seal is even and has no gaps.
Cleaning
After stopping the machine, check the center seal area for residue. Wipe the roller and heating bar with a non-woven cloth and a small amount of alcohol. Pay attention to grooves where debris collects. Keep contact surfaces clean.
Film check
Uneven or thin film can cause local seal failure. Replace it with film of consistent thickness and no wrinkles. Adjust the film feed tension device so the film enters the sealing area flat.
Roller condition
Long use can wear or deform the roller surface. Stop the machine and turn the roller by hand. Check how it contacts the heating bar. If there are dents or gaps, replace the roller.
Drive system
Abnormal noise or roller speed fluctuation can come from a loose drive belt or a sticking chain. Tighten loose parts, lubricate chain joints, and check motor stability so power transmission stays steady.
If center seal rollers, heating bars, or drive parts are worn, Hansheng Automation can machine replacements from customer drawings in single pieces or small batches.
