A comprehensive study of low-density polyethylene in capillary flow

Mitsoulis, E; Zisis, T; Ansari, M; Hatzikiriakos, SG

dc.contributor.author	Mitsoulis, E	en
dc.contributor.author	Zisis, T	en
dc.contributor.author	Ansari, M	en
dc.contributor.author	Hatzikiriakos, SG	en
dc.date.accessioned	2014-03-01T02:52:49Z
dc.date.available	2014-03-01T02:52:49Z
dc.date.issued	2011	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/36090
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-84857877837&partnerID=40&md5=f71b3b65eda5a3b14078a53422824513	en
dc.subject	Capillary flow	en
dc.subject	Excess pressure losses	en
dc.subject	Low density polyethylene	en
dc.subject.other	Bagley correction	en
dc.subject.other	Capillary dies	en
dc.subject.other	Comprehensive studies	en
dc.subject.other	Effect of pressure	en
dc.subject.other	Excess pressure	en
dc.subject.other	Experimental data	en
dc.subject.other	L/D ratio	en
dc.subject.other	Low density	en
dc.subject.other	Nonisothermal	en
dc.subject.other	Pressure dependence	en
dc.subject.other	Relaxation modulus	en
dc.subject.other	Rheological characterization	en
dc.subject.other	Slip effects	en
dc.subject.other	Time-temperature	en
dc.subject.other	Viscous models	en
dc.subject.other	Capillarity	en
dc.subject.other	Capillary flow	en
dc.subject.other	Plastic products	en
dc.subject.other	Pressure effects	en
dc.title	A comprehensive study of low-density polyethylene in capillary flow	en
heal.type	conferenceItem	en
heal.publicationDate	2011	en
heal.abstract	The capillary flow of a commercial LDPE melt was studied both experimentally and numerically. The excess pressure drop due to entry (Bagley correction), the compressibility, the effect of pressure on viscosity and the possible slip effects on the capillary data analysis have been examined. Using a series of capillary dies having different diameters, D and length-to-diameter L/D ratios, a full rheological characterization has been carried out, and the experimental data have been fitted both with a viscous model (Carreau-Yasuda) and a viscoelastic one (K-BKZ/PSM model). Particular emphasis has been given on the pressure-dependence of viscosity, with a pressure-dependent coefficient βp. For the viscous model, the viscosity is a function of both temperature and pressure. For the viscoelastic K-BKZ model, the time-temperature shifting concept has been used for the non-isothermal calculations, while the time-pressure shifting concept has been used to shift the relaxation moduli for the pressure-dependence effect. It was found that only the viscoelastic simulations were capable of reproducing the experimental data well, while any viscous modeling always underestimates the pressures, especially at the higher apparent shear rates and L/D ratios.	en
heal.journalName	Society of Plastics Engineers - EUROTEC 2011 Conference Proceedings	en