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November 22, 2006
Shear slitting and scratching
Contributed by Tim Walker -
Question:
Can shear slitting scratch a film web? Is there any relationship between slit and web speed?
The only shear slitting has problems with slitting-related scratches. The scratch is usually near the slit edge, created by the web traveling under or over the top or bottom knife in the overlap region. Too much overspeed will make these scratches worse. I don’t believe that line speed if important. Usually these scratches are eliminated by changing the knife geometry. I have heard of many shear slitting processes change the both shear knives, especially the top knife, to a wider design to avoid scratching.
Posted by Tim Walker at November 22, 2006 08:00 AM
