Apparatus for measuring the rheological properties of materials

• Main Author: MAXWELL; BRYCE
• Format: Patent
• Language: English
• Published: 02.08.1988
• Edition: 4
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

An apparatus for measuring the rheological properties of polymer melts, polymer solutions and other materials including the placement of a specimen of the material to be tested within the intervening space between a forcibly rotatable member and a stationary member both of which have a common axis of symmetry, further including a drive device to forcibly rotate the rotatable member about the common axis of symmetry to shear the specimen, also including the measuring of the force required to shear the specimen, in order to determine the modules of elasticity, yield stress and steady state viscosity of the specimen, further abruptly stopping the rotation of the forcibly rotated member and measuring the stress relaxation of the specimen as a function of time, or alternatively, releasing the forcibly rotated member and measuring the recoverable strain and rate of strain recovery as a function of time for the purpose of determining the elastic properties of the specimen, and further including an alignment bearing device such that the axis of rotation of the rotatable member is co-axial with the stationary member and further bearing device consisting of axially located small diameter pins rigidly fixed to and protruding from the stationary member and the main frame of the apparatus into axially located holes in the other members to maintain co-axial rotation with very low frictional resistance to the relative rotation of the rotatable and non-rotatable members.