Monsanto Corporation

Monsanto Company

Michael J Stolc

David G Rusling

Michael Mathews

Robert I Barker

David King

An apparatus for measuring viscoelastic properties of rubbery materials is disclosed. The instrument comprises two opposed dies having temperature and pressure controling means, means for initiating oscillatory rotation of one of the dies whereby the sample is cooled during its residence between the dies and reheated whereby torque measurements are carried out during the period of cooling. A method for operating the claimed apparatus is also disclosed.

Method and instrument for viscoelastic measurements

The invention relates to an instrument and method for measuring the viscoelastic properties of rubber and like materials comprising two opposed dies, each die having a die housing, the dies and housings being moveable between an open position and a closed position, and wherein: a) each die is separated from its housing by a substantially uniform circumferential gap such that the die is rotatable relative to its housing, and one die is rotatable relative to the other, b) in the closed position, the two dies define between them a cavity for holding under pressure a sample of material to be tested, c) the design of the dies and housings is such that during movement from the open position to the closed position, a sample of test material located between the dies is compressed so that excess material is extruded radially from between the dies, across the gap between each die and its housing and through a narrowing space separating the housings until the two housings reach their closed position, in which position the said space is sealed. The radial dimension of the gap between each die and its housing is significantly less than in prior art instruments, and sheets of film of heat and distortion-resistant material are used to bridge the gaps.

Instrument and method for viscoelasticity measurements

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.

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Swindon, United Kingdom

Michael J Stolc