Lateral paper web shifting during commercial heat set web offset printing DOI 10.14622/JPMTR-2010

Abstract

Paper properties and their role in preventing lateral web movement from cross machine air flows in the drying section during normal heat set web offset litho printing operations were examined. Tensile properties of sheets were measured at various moisture contents and then used to determine the equilibrium stress–strain relationship for papers at moisture contents typical of heat set web offset printing. Air permeability, creep, hygroexpansion, and ultrasonic measurement of tensile stiffness orientation module were evaluated against lateral web movement on heat set web offset litho press. It was found that the only item of interest from these results with respect to the lat-eral movement performance is the ratio between tensile stiffness orientation modules in the machine direction and cross machine direction, indicating orientation of the fibers in the paper web, and showing that more oriented fibers are less likely to shift on heat set web offset litho printing press. Understanding the effect of water absorption and absorption rate on the stress–strain relationship of paper may yield further understanding of web break tendency during heat set web offset printing.