SPINNING VISCOSITY

The use of fibre spinning and related experiments is examined and the presentation of results in terms of a ''spinning viscosity'' is propos ed. A re-examination of results for convected Maxwell and Jeffreys mod els and FENE dumbbell models shows the importance of the flow history prior to the spinning. Some undesirable ways of treating data are disc ussed. Out of this comes a discussion of the appropriateness of using viscosity or modulus as a measure of a material response and of using rate of strain or strain as a variable. The work is theoretical, but l eads to a proposal for testing the ways in which experimental data are treated. A definition of a ''spinning viscosity'' is offered, and the idea that one should only obtain one value from one spinning experime nt is emphasized.