Testing rubber

摘要

Apparatus and method for testing unvulcanized rubber or rubber-like materials can work at high shear rates (e.g. 100 sec-1) as a result of applying and maintaining pressure on the test sample as it is being sheared by a rotor in a test chamber. The rotor is smooth-faced. Both conditions simulate more accurately the forces acting on such materials in such operations as extrusion. The test material is transferred into the test chamber through transfer ports from a transfer chamber by a pressure member which continues to exert pressure on material in the transfer chamber, which may be a next test sample. Specific operating steps of the rotor at varying speeds and directions to assess various useful parameters of the test material (including not only viscosity but also elasticity) are described, together with a mathematical model for rationalizing the behavior of the material under these test conditions.