D1646 1.1 These test
methods cover procedures for measuring a property called Mooney
viscosity. Mooney viscosity is defined as the shearing torque resisting
rotation of a cylindrical metal disk (or rotor) embedded in rubber
within a cylindrical cavity. The dimensions of the shearing disk
viscometer, test temperatures, and procedures for determining Mooney
viscosity are defined in these test methods. 1.2 When disk
rotation is abruptly stopped, the torque or stress on the rotor
decreases at some rate depending on the rubber being tested and the
temperature of the test. This is called "stress relaxation" and these
test methods describe a test method for measuring this relaxation.
Viscosity as used in these test methods is not a true viscosity and
should be interpreted to mean Mooney viscosity, a measure of shearing
torque averaged over a range of shearing rates. Stress relaxation is
also a function of the test configuration and for these test methods the
results are unique to the Mooney viscometer. 1.3 When
compounded rubber is placed in the Mooney viscometer at a temperature at
which vulcanization may occur, the vulcanization reaction produces an
increase in torque. These test methods include procedures for measuring
the initial rate of rubber vulcanization. 1.4 ISO 289
Parts 1 and 2 also describes the determination of Mooney viscosity and
pre-vulcanization characteristics. In addition to a few insignificant
differences there are major technical differences between ISO 289 and
this test method in that ISO 289 does not provide for sample preparation
on a mill, while this test method allows milling sample preparation in
some cases prior to running a Mooney viscosity test. This can result in
different viscosity values for some rubbers.
Standard Test Methods for
Rubber-Viscosity, Stress Relaxation, and Pre-Vulcanization
Characteristics
(Mooney Viscometer)
REAL Services 700 Portage Trail Cuyahoga Falls, OH 44221.3057
voice: 330.630.3700 fax: 330.630.3733
© 1995-2005 REAL Services® All Rights Reserved