CORRELATION OF VARIOUS SHIFT FACTORS.

The correlation of various shift factors obtained from the flow characteristics are analyzed theoretically and investigated experimentally. The samples used were polymethyl methacrylate resin (to which the method of reduced variables is applicable) and polypropylene resin (to which the method of reduced variables is not applicable). The ratio of the temperature shift factor at constant shear rate to the temperature shift factor at constant shear stress, and the ratio of the pressure shift factor at constant shear rate to the pressure shift factor at constant shear stress, respectively, that is expressed in the form of differential coefficient corresponds to the generalized flow index. These relationships are valid in either case whether the method of reduced variables is applicable or not applicable. Also, these relationships are able to be applied for every kind of fluid.