Abstract
Using thin filament equations, it was shown that the cross-sectional area of spinline immediately below the spinneret decreases with increasing spinline tension, in the spinning of upper convected Maxwell fluids. The decrease obeys the equation of rubberlike elasticity. It was found that the filament thickness at upstream end must decrease with increasing tension when the flow within the spinneret hole is kept constant and that the well known unattainable region in draw ratio does not in fact exist in this case.
