Abstract: The modulus of a plastic polymer is measured by extruding a strand of the polymer vertically downward through an orifice while accurately measuring the diameter of the strand, cutting off the strand and weighing it, and dividing the strand weight by the square of the difference in strand diameter to give a quotient representative of the modulus of the polymer. The method and apparatus are especially useful in measuring the green strength of a vulcanizable elastomer, so as to characterize its behavior during processing into a finished article.

Abstract: The rheological properties of an extrudable material can be measured by extruding a strand of the material, measuring its diameter continuously, to give a series of diameter values, interpreting the variations in the strand diameter so as to characterize the surface of the strand, and deriving rheological data from the surface characteristics of the strand. The variations in the strand diameter can be interpreted as to peak-to-peak amplitude, average diameter value, the frequency of significant extreme values, standard deviations from a mean value, and the like. By means of these mathematical characterizations, the rheological behavior of the extrudable material can then be derived. The scorch behavior of a curable elastomer can be measured. The heterogeneity of a rubber compound can be described, or the macromolecular properties of a polymer can be measured (such as "gel", or degree of cross-linking.