Rubber - Rotorless Shear Rheometers   ASTM D 6204: Standard Test Method for Rubber - Measurement of Unvulcanized Rheological Properties Using Rotorless Shear Rheometers     This standard covers the use of rotorless oscillation shear rheometers to measure and analysis of the flow properties of rubber and rubber compounds. These rheological properties of materials are critical in factory processing procedures.    Test Method   ASTM D6204 - Section 4. Summary of Test Method: 4.1 A rubber test specimen is contained in a die cavity that is closed and maintained at an elevated temperature. The cavity is formed by two dies, one of which is oscillated through a rotary amplitude. This action produces a sinusoidal torsional strain in the test specimen, resulting in a sinusoidal torque, which measures a viscoelastic quality of the test specimen. The test specimen can be either a raw natural or synthetic rubber or an uncured rubber compound. Apparatus   ASTM D6204 - Section 6.Apparatus: 6.1 Torsion Strain Rotorless Oscillating Rheometer With a Sealed Cavity?This type of rheometer measures the elastic torque S’ and viscous torque S” produced by oscillating angular strain of set amplitude and frequency in a completely closed and sealed test cavity.   The standard covers everything from the sealed die cavitiy, closing mechanism, die gap, torque measuring system etc.   ASTM D6204 - Fig. 1 Typical Sealed Torsion Shear Rotorless Curemeter ST-106R MDR Rheometer   Rheometer Software ST-106R MDR Rheometer Product Page