Common Faults & Solutions for Bag Making Machine
This document summarizes the frequent problems during operation: unable to cut film, weak sealing, film deviation, and inaccurate bag length. Below are the main causes and quick troubleshooting steps.
1. Unable to Cut Film (Cutter Fault)
This is one of the most troublesome issues, usually caused by blunt blades or unbalanced temperature/pressure.
• Causes:
Blunt cutter, unaligned upper/lower blades, insufficient heat-sealing temperature, or jammed mechanism.
• Solutions:
◦ Grind or replace the cutter if worn out.
◦ Adjust balance: Check the clearance of the cutter slider to ensure even pressure.
◦ Adjust temperature and pressure: Increase heat-cutter temperature properly; check if the pressure spring is too loose.
2. Weak Sealing (Heat Sealing Fault)
Bags are not sealed tightly, easy to leak air or tear open.
• Causes:
Insufficient temperature, excessive speed, uneven pressure, or poor film quality.
• Solutions:
◦ Increase temperature according to film thickness (PE film: usually 180–200°C).
◦ Reduce speed to allow enough time for heat sealing.
◦ Adjust pressure: Check if the sealing bar is flat and adjust spring pressure evenly.
3. Film Deviation (Unstable Feeding)
Film sways left and right or runs to one side during conveying.
• Causes:
Photoelectric eye failure, uneven rubber roller pressure, or unparallel guide rollers.
• Solutions:
◦ Clean the photoelectric sensor and adjust sensitivity.
◦ Adjust rubber rollers: Ensure they are horizontal and pressure is balanced on both sides.
◦ Check guide rollers: Re-align if severely deviated.
4. Inaccurate Bag Length (Inconsistent Sizing)
Finished bags vary in length and unstable in size.
• Causes:
Slippage of rubber rollers, incorrect tracking of the photoelectric eye, or unstable tension.
• Solutions:
◦ Tighten rollers: Check compression springs to prevent slipping.
◦ Adjust photoelectric eye: Correct position and polarity to ensure accurate color mark detection.
◦ Stabilize tension: Adjust unwinding tension to avoid over-tight or over-loose film.
5. Daily Maintenance Tips
• Lubricate moving parts every 48 hours to prevent noise and jamming.
• Keep rubber rollers and conveyors clean from dust and plastic scraps.
• Eliminate static electricity: Install static eliminator or ground connection if static causes blockage.
Safety Notice
Always stop the machine and disconnect power before adjusting the heat-sealing bar or cutter.
Allow the blades to cool down to avoid scalding.
