Abstract: A method and apparatus for devulcanizing cured or cross-linked elastomers. The method includes subdividing elastomeric raw material into small particle form, confining the particles of elastomer under high force, as in a screw extruder or the like and, as the particles remain confined, imparting ultrasonic energy to the mass to effect devulcanization. Energy is fed to the confined particles transversely of the axis along which they are advancing, and energy from a source is reflected off a portion of the apparatus and back into the treatment zone so as to achieve maximum energy utilization. In particular instances, reflection of energy is achieved by providing opposed, powered ultrasonic horns that resonate in phase with each other. In another embodiment, oppositely directed, resonantly tuned horns are used, with less than all such horns being powered and the remainder being passive or unpowered reflecting horns who resonant frequency is tuned to that of the powered horn.

Abstract: A method and apparatus for devulcanizing cured or cross-linked elastomers. The method includes subdividing elastomeric raw material into small particle form, confining the particles of elastomer under high force, as in a screw extruder or the like and, as the particles remain confined, imparting ultrasonic energy to the mass to effect devulcanization. Energy is fed to the confined particles transversely of the axis along which they are advancing, and energy from a source is reflected off a portion of the apparatus and back into the treatment zone so as to achieve maximum energy utilization. In particular instances, reflection of energy is achieved by providing opposed, powered ultrasonic horns that resonate in phase with each other. In another embodiment, oppositely directed, resonantly tuned horns are used, with less than all such horns being powered and the remainder being passive or unpowered reflecting horns who resonant frequency is tuned to that of the powered horn.

Abstract: A method and apparatus for rapidly determining the cure state of an annular rubber or elastomeric article is provided. The article is placed so that an inner hole portion fits over separable parts of a test fixture, and tension is induced in a stepwise manner by moving the separable parts apart in discrete incremental steps. The tension is allowed to relax between the steps. By generating a force/deflection curve in this way, the user may optimize the cure state of the tested articles by controlling the cure time and temperature of a manufacturing process in response to the measured data.

Abstract: A test fixture apparatus for measuring the bending stiffness of specimens of flexible materials such as elastomers and like polymers. The preferred form includes two elements, an anvil member and a yoke member. The yoke includes a crosspiece and two pairs of depending legs forming parallel, spaced apart, inverted "V"s. Rollers extend between points on the lower parts of the legs to support the test specimens. The anvil member includes a crosspiece and a single pair of arms positioning a roller for applying a downward load to the center of the specimen held on the yoke rollers. The rollers allow the surface-soft specimens to slide over rather than dig into their supports, and this provides more accurate, repeatable readings of the bending forces applied to the specimens.