Calendering of pseudoplastic and viscoplastic sheets of finite thickness

Sofou, S; Mitsoulis, E

dc.contributor.author	Sofou, S	en
dc.contributor.author	Mitsoulis, E	en
dc.date.accessioned	2014-03-01T01:19:59Z
dc.date.available	2014-03-01T01:19:59Z
dc.date.issued	2004	en
dc.identifier.issn	8756-0879	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/15793
dc.subject	Bingham plastic model	en
dc.subject	Calendering	en
dc.subject	Finite sheets	en
dc.subject	Herschel-Bulkley model	en
dc.subject	Power-law model	en
dc.subject	Pseudoplasticity	en
dc.subject	Sheet thickness	en
dc.subject	Viscoplasticity	en
dc.subject	Yield stress	en
dc.subject	Yielded/unyielded regions	en
dc.subject.classification	Materials Science, Coatings & Films	en
dc.subject.other	Approximation theory	en
dc.subject.other	Boundary conditions	en
dc.subject.other	Calendering	en
dc.subject.other	Integration	en
dc.subject.other	Mathematical models	en
dc.subject.other	Pressure distribution	en
dc.subject.other	Viscoplasticity	en
dc.subject.other	Yield stress	en
dc.subject.other	Bingham plastic model	en
dc.subject.other	Finite sheets	en
dc.subject.other	Herschel-Bulkley model	en
dc.subject.other	Power law model	en
dc.subject.other	Pressure gradient	en
dc.subject.other	Pseudoplasticity	en
dc.subject.other	Sheet thickness	en
dc.subject.other	Plastic sheets	en
dc.title	Calendering of pseudoplastic and viscoplastic sheets of finite thickness	en
heal.type	journalArticle	en
heal.identifier.primary	10.1177/8756087904047660	en
heal.identifier.secondary	http://dx.doi.org/10.1177/8756087904047660	en
heal.language	English	en
heal.publicationDate	2004	en
heal.abstract	The lubrication approximation theory (LAT) is used to provide numerical results for calendering sheets with a desired final thickness. The Herschel-Bulkley model of viscoplasticity is used, which reduces with appropriate modifications to the Bingham, the power-law and the Newtonian models. For a desired final sheet thickness, the results give the required thickness of the entering sheet as a function of the dimensionless power-law index (in the case of pseudoplasticity) and the dimensionless yield stress (in the case of viscoplasticity). The corresponding pressure-gradient and pressure distributions are also given. The integrated quantities of engineering interest are calculated. These include the maximum pressure, the roll-separating force, and the power input to the rolls. Both pseudoplasticity and viscoplasticity lead to thicker sheets than the Newtonian model for large entry thickness ratios, while they lead to thinner sheets for small entry thickness ratios. In the case of viscoplastic sheets, the interesting yielded/unyielded regions appear as a function of the dimensionless yield stress. All engineering quantities, given in a dimensionless form, increase substantially with the departure from the Newtonian values. A test case for calendering a plastic sheet with a yield stress is given as an example of implementing the present results. © 2004 Sage Publications.	en
heal.publisher	SAGE PUBLICATIONS LTD	en
heal.journalName	Journal of Plastic Film and Sheeting	en
dc.identifier.doi	10.1177/8756087904047660	en
dc.identifier.isi	ISI:000225553100002	en
dc.identifier.volume	20	en
dc.identifier.issue	3	en
dc.identifier.spage	185	en
dc.identifier.epage	222	en