Elongational rheology of fiber forming polymers

The elongational rheology of some fiber forming polymers, such as polypropylene (PP), polyethylene (PE), nylon 66, and lyocell (cellulose dissolved in N-Methylmorpholine/water) solutions, has been characterized using hyperbolic convergent dies in a capillary rheometer, at different Hencky strains, processing temperatures, and as a function of elongational strain rates up to 600 s−1. The influence of melt flow rate (MFR) and molecular parameters is studied and it is shown that the elongational viscosity curves can be shifted with respect to both temperature and Hencky strain. C 2005 Springer Science + Business Media, Inc.