Abstract: A method of operating an instrument for testing the physical properties of materials in which each of a series of samples of the material to be tested is placed in a test position located between dies, the dies are closed to mould the material to a test shape, a test is carried out on the sample in the mould and after completion of the test the dies are opened and the sample is removed from the test position is characterised in that a film of material which is substantially non-adhesive to the dies under the conditions of the test is provided to cover those surfaces of the sample which, in the absence of the film, would be in contact with the dies, each sample in turn is conveyed to the test position, and mechanical elements are provided for removing each sample from the test position after the completion of the test. Apparatus suitable for use in the method of the invention is also provided.

Abstract: A method and apparatus for testing samples of viscoelastic materials are shown, in which the sample is contained under pressure between two dies and the forces involved in rotating one die with respect to the other. The method uses different frequencies of oscillatory rotation at different temperatures. The apparatus uses dies with discontinuous protrusions which overlap each other.

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.

Abstract: The dimension across an extrudable material is monitored during an extrusion period and during a stationary period.

Abstract: Evaluating extrudable material by forcing such material through an outlet of a chamber by means of a movable member then stopping and securing the movable member at a predetermined position and measuring the force on the material as it decays with time.

Abstract: A method of measuring width of an object between two of its edges is disclosed wherein the object is placed between the edges of an aperture and a narrow beam of parallel light is directed through a rotating prism so as to scan the aperture and object therein, the light passing through the aperture being detected, and electrical signals generated proportional to the time the object interrupts the light are summed with correction signals generated in synchronization with the sweep of light across the aperture which are representative of the variation in sweep velocity to provide a composite signal representative of width of the object independent of its position in the aperture.