New Ideas on Web Troughs and Their Consequences

Presented by Dilwyn Jones, Emral Ltd

Troughs are gentle ripples in low and moderate thickness webs between rollers in many R2R machines. If they grow large enough, wrinkles, creases and folds can form on the next roller and cause product damage and waste. This paper outlines a new analysis of the troughs, and what they tell us about the compressive stresses in the incoming and outgoing web, together with sideways movement. Applications to roller misalignment, diameter variations and helical grooving will be discussed.