Corrugations, prevention

1. Corrugations are soft spots between two hard spots.
— in dealing with corrugations, the operator must differentiate between calender and slice problems.
2. If problem is in the calender, take air off hard spots and put it into center of soft spots.
3. Check that the winder shaft is true.
— check adjustment of spreader bars.
— look for any irregularity on spreader bar or on a roll.