b'CREPING PROCESS EFFICIENCIESFigure 6. Picture of base sheet delamination via optimized creping.CREPE RATIOStretch is an important property of the tissue base sheet and finished product. It plays a role for efficient converting, dispensing and perceived handfeel. Base sheet elongation is comprised of two components: Figure 7. Representation of bulk loss due to mechanical stretch added via crepe ratio.Mechanical stretch: imparted via the crepe ratio (reducing theThe resulting sheet explosionConversely, if we take the extreme speed of the reel with respect toproduces disruption of the sheetopposite case of a cotton ball, where the Yankee) structure and de-densification of theits structure is nothing more than Internal stretch: Disruption offiber matrix.This allows for fiberfiber entanglement, we can see that fiber-to-fiber bonds to allowslippage within the matrix. In thisindividual fiber slippage within the for slippage between fibersway, internal stretch becomes a goodstructure results in much less caliper which results in % elongationindicator of high sheet disruption,loss during pull out. This action also of the sample in excess of thewhich is necessary for resilient bulkprovides for increased internal stretch, mechanical stretch imparted togeneration. allowing the tissue maker to achieve the sheet via the crepe ratio.stretch values in excess of the crepe Conversely, crepe ratio stretch,ratio being employed. We can see that Internal stretch is an excellent predictorbeyond a certain point, not onlycreating bulk that will best endure of both bulk to basis weight efficiencyreduces production rates, but itthrough the converting processcreating as well as perceived softness. In orderresults in ever diminishing returnsrequires an exploded, delaminatebulk that will to create internal stretch, the sheetwith respect to bulk generation.structure. best endure must be adhered to the Yankee via theThe bulk created in this manner onUltimately, tissue makers would like tothrough the adhesive coating in a highly uniformthe tissue machine is rapidly lostproduce tissue at the lowest possibleconverting manner 5. via any pulling through a winder orcrepe ratio in order to maximizeprocess converting line. We can representefficiency. Creping pocket anglerequires an While crepe ratio can impartthis with an uncreped sheet of paperselection along with the adhesiveexploded, mechanical stretch, internal stretchto represent mechanically inducedpackage optimization are the biggestdelaminate is imparted via high energy creping.folds. drivers of what final crepe ratio willstructure.26 TISSUE TECHNOLOGY INTERNATIONAL'