It is well known that the elongational flow behavior which dominates manyprocessing techniques can not be determined from shear experiments. The patented RHEOTENS melt tensile testing technique has proven to be highly reproducible and sensitive, and will differentiate even polymer melts showing small differences in molecular structure which can not be detected with analytical methods. > Tandem pulley system 1 (option): An additional pair of pull-off wheels have been integrated to prevent sticking of the elongated polymer strand once it has passed the first pair of pulleys. > Extended speed control...

Figure 1: Looking at the RHEOTENS diagram,the maximum draw-down speed (v) is a relativemeasurement for the "elongation" of the melt, while the maximum force (F) is a relative measurement for the melt strength. The RHEOTENS test is a rather complicated functionof the characteristics of the polymer, dimensionsof the capillary, length of the spin line and of the extrusion history: F=F (Polymer,Geometry,Process Conditions)Figure 2: "Super-Master-Curve" In the first step approach, invariance with respectto different mass flow rates can be found. Thisreduces the originally 16 RHEOTENS curves inour...