caa a22 4500 465814263 CHVBK 20180323112123.0 cr unu---uuuuu 170327e19900901xx s 000 0 eng 10.1007/BF01376788 doi (NATIONALLICENCE)springer-10.1007/BF01376788 Elongational viscosity by fiber spinning [Elektronische Daten] [Z. Chen, T. Papanastasiou] Isothermal melt, fiber-spinning was recently analyzed by means of a nonlinear, integral, constitutive equation that incorporates shear history effects, spectrum of relaxation times, shear-thinning, and extension thinning or thickening when either the drawing force or the draw ratio is specified. The predictions agreed with experimental data on spinning of polystyrene, low-density polyethylene, and polypropylene melts. The predicted apparent elongational viscosity along the threadline (which, as shown in this work, must be identical to that measured experimentally by fiber spinning type of elongational rheometers) is compared with the true elongational viscosity predicted by the same constitutive equation under well-defined experimental conditions of constant extension rate, independent of any strain history. It is concluded that the apparent elongational viscosity, as measured by fiber-spinning, approaches the true elongational viscosity at low Weissenberg numbers (defined as the product of the liquid's relaxation time multiplied by the extension rate). At moderate Weissenberg numbers, the two viscosities may differ by an order of magnitude and their difference grows even larger at high Weissenberg numbers. Steinkopff, 1990 F iber-spinning nationallicence elongational v iscosity nationallicence i ntegral model nationallicence Chen Z. Macromolecular Research Center, University of Michigan, Ann Arbor, Michigan, USA aut Papanastasiou T. Department of Chemical Engineering, University of Michigan, Dow Building, 48109-2136, Ann Arbor, MI, USA aut Rheologica Acta Steinkopff-Verlag 29/5(1990-09-01), 385-389 0035-4511 29:5<385 1990 29 397 https://doi.org/10.1007/BF01376788 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01376788 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Chen Z. Macromolecular Research Center, University of Michigan, Ann Arbor, Michigan, USA aut NATIONALLICENCE 700 1- Papanastasiou T. Department of Chemical Engineering, University of Michigan, Dow Building, 48109-2136, Ann Arbor, MI, USA aut NATIONALLICENCE 773 0- Rheologica Acta Steinkopff-Verlag 29/5(1990-09-01), 385-389 0035-4511 29:5<385 1990 29 397 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer