Wrinkling remains one of the top causes of converting process waste. Though wrinkles created by roller misalignment and web bending (shear wrinkles) are well-understood, nearly all the published research and modeling has been based on narrow web experiments (less than 15-in wide). Other causes of wrinkling, such as wrinkling due to roller deflection or uneven nipping, have had little or no published results. Similar to wrinkling, most published research on spreading and anti-wrinkle rollers has been based on narrow web experiments.

This paper will review the results from wide web wrinkling due to roller misalignment for various materials and compare the experimental wrinkling results to isolated-span shear wrinkle models. Also, we will share results from over ten different roller designs (including various concave roller profiles) demonstrating their relative effectiveness in preventing shear wrinkles and their ability to spread a web slit down its center. Lastly, during our shear wrinkles trials we unintentionally created tracking or gathering type wrinkles from a deflecting rollers at the top of a long, vertical span. This led to an experiment investigation to eliminate these wrinkles and an upgraded model to predict these wrinkles caused by roller deflection in the negative bow direction.