Numerical simulation of the wire-pinning process in PET film casting: Steady-state results

Christodoulou, K; Hatzikiriakos, SG; Mitsoulis, E

dc.contributor.author	Christodoulou, K	en
dc.contributor.author	Hatzikiriakos, SG	en
dc.contributor.author	Mitsoulis, E	en
dc.date.accessioned	2014-03-01T02:11:33Z
dc.date.available	2014-03-01T02:11:33Z
dc.date.issued	2012	en
dc.identifier.issn	00011541	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/29940
dc.subject	Film casting	en
dc.subject	Film pinning	en
dc.subject	Finite element model	en
dc.subject	PET resins	en
dc.subject	Wetting of die lip	en
dc.subject.other	Casting process	en
dc.subject.other	Film casting	en
dc.subject.other	Finite element models	en
dc.subject.other	Governing equations	en
dc.subject.other	Machine directions	en
dc.subject.other	Melt flow	en
dc.subject.other	Nonuniform	en
dc.subject.other	Parameter range	en
dc.subject.other	PET films	en
dc.subject.other	Pinning forces	en
dc.subject.other	Pinning points	en
dc.subject.other	Static and dynamic	en
dc.subject.other	Static contact angle	en
dc.subject.other	Air entrainment	en
dc.subject.other	Contact angle	en
dc.subject.other	Polyethylene terephthalates	en
dc.subject.other	Wetting	en
dc.subject.other	Wire	en
dc.subject.other	Dies	en
dc.title	Numerical simulation of the wire-pinning process in PET film casting: Steady-state results	en
heal.type	journalArticle	en
heal.identifier.primary	10.1002/aic.12734	en
heal.identifier.secondary	http://dx.doi.org/10.1002/aic.12734	en
heal.publicationDate	2012	en
heal.abstract	Poly(ethylene terephthalate) (PET) film casting involves melt flow through a slot die, across a small span, and onto a fast moving quench drum. In the ""wire-pinning"" casting process, a thin electrified wire close to the line of contact with the drum creates a strong pinning force that delays air entrainment to higher line speeds. Nonuniform wetting of the die lips by the extruded melt is thought to be responsible for the formation of streaks, a defect in the machine direction. A finite element model of the film casting process with wire pinning was developed to assist in understanding what causes significant wetting of the lips and whether this can be avoided by electrostatic pinning. The solution of the governing equations provide the location of the static and dynamic contact lines, thus finding the wetting and pinning points in the process. The simulations investigate the sensitivity of the static wetting line locations on the die lands to the imposed values of static contact angle and die-lip gap. It was found that while the contact angle has a small effect on the extent of die-lip wetting within the parameter ranges examined, there is a considerable chance that the feed slot surfaces can be dewetted. This seems to be the greatest danger for causing streaks rather than excessive wetting of the die lands. © 2011 American Institute of Chemical Engineers.	en
heal.journalName	AIChE Journal	en
dc.identifier.doi	10.1002/aic.12734	en
dc.identifier.volume	58	en
dc.identifier.issue	7	en
dc.identifier.spage	1979	en
dc.identifier.epage	1986	en