Can die swell be predicted?

Summary A calculational scheme has been developed to predict die swell values which are defined as the value after completion of the elastic recovery. The constants of the equations have been evaluated at 190 °C from the known results of several polyethylene samples. With the similar type but different sample of polyethylene, it is shown that the prediction is with ±3.4% for the shear rates of 90 to 600 sec^–1, for the dies ofL/D 2–20 and at temperature of 200 °C.With 3 figures and 4 tables