Investigation of the effect of swelling and shrinkage on the wrinkling response of locally wetted papers subjected to tension with application to web-fed ink-jet printing

For web-fed ink-jet printing, wrinkling can occur during printing and persist and become worse after sheeting. The wrinkles formed during local wetting and drying was successfully characterized using a lab scale system complemented with the simple moire fringe technique. The two main parameters used to characterize these wrinkles were the wavelength and the height of the wrinkles. A buckling analysis was completed for the prediction of wet wrinkles which provided an expression for the critical load at which paper buckles to form wrinkles and an expression for the wavelength. A new method was developed to measure the wet expansion and subsequent shrinkage on drying of a sheet. It was found that wet wrinkling occurs due to the restriction of swelling of the sheet upon wetting. During drying, wet wrinkling is diminished and new wrinkling occurs due to subsequent shrinkage of the wetted regions.