A loose edge roll on a slitting machine is a common problem. Check in this order: edge tension on the rewind, guide roll parallelism, web guide system, slit edge quality, and rewind shaft straightness. This sequence addresses most common cases.
Correct edge tension on the rewind
Check the edge bladder seal on the air shaft. If it leaks, replace the aging seal ring to restore the expanding support force at the edge shaft.
Open the tension control screen. Raise the separate tension parameter for the edge zone. Keep the tension difference between the edge and the center within 5%. For thin film, set edge tension slightly lower than the center to avoid tearing the edge. For thick sheet and hard material, raise edge tension as needed to match rewinding.
Turn the rewind shaft by hand. Check how tightly the edge roll layers are pressed together. After tension adjustment is confirmed, run a trial.
Align guide roll parallelism
Use a feeler gauge or dial indicator to check the height difference at both ends of the pull rolls and the unwind and rewind guide rolls. Acceptable deviation should be within 0.05 mm.
Loosen the mounting bolts on the guide roll support. Adjust the support height until the deviation is within tolerance. Retighten the bolts and run a trial to verify.
If the guide roll edge is worn, sand the worn area with fine sandpaper or replace the guide roll. This removes the slack gap at the material edge. Hansheng Automation can machine custom guide rolls, roll shafts, mounting brackets, and wear parts from customer drawings, in single pieces or small batches.
Adjust the photoelectric web guide system
Check the mounting position of the photoelectric web guide sensor. Make sure it points accurately at the effective edge of the material, with no obstruction or offset.
Switch the slitting machine to manual mode. Trigger the web guide action. Confirm the material can stay steadily at the center reference position.
Reset the reference point of the web guide system. This clears offset error that builds up over long runs. It prevents single-side drift that causes loose edge winding.
Improve slit edge quality
Stop the machine and check the cutting edge of the slitting blade. If it is chipped or dull, sharpen it or replace it. The slit edge should be flat, with no burr or curl.
For thin material that curls easily, add an edge press roll before the rewind station. This flattens the slit edge before it enters rewinding.
Clean trim waste from the slitting station. Do not let waste lodge in the edge gap, because that can prevent tight winding.
Check rewind shaft straightness
Use a dial indicator to check radial runout of the rewind shaft. If runout exceeds 0.1 mm, the shaft may be deformed.
Straighten the deformed shaft, or replace it with a qualified rewind shaft.
Safety note
Before any adjustment, stop the machine and cut power. Lock the emergency stop switch. Confirm the machine is fully stopped before work begins. This avoids injury from rotating or moving parts.
Beyond the slitting machine parts discussed above, our precision component customization is not limited to this topic. Hansheng Automation machines medical device components, printing machinery parts, filling machinery parts, yacht precision components, RC car precision components, tobacco packaging machinery parts, food machinery parts, and other custom parts. We work from customer drawings and deliver one-off or batch parts to the required material, tolerance, and surface finish. Our scope is precision components, not complete machines.
