ODR (oscillating disc rheometer) and MDR (moving die rheometer) are the two types of rheometers used in the rubber business. However, they serve similar functions.

We close the rheometer after placing a piece of raw, unvulcanized rubber within its cavity. The type of compound and the crosslinking technique determine the temperature at which the rubber compound is exposed to pressure (vulcanization). Inside the cavity of the ODR rheometer is a biconical rotor that oscillates left and right by an average of 3 degrees. The sensor measures the resistance that the rubber exerts against the rotating rotor during the vulcanization process.

The stiffness or viscoelastic qualities of the compound determine the torque needed to cause oscillation. Thus, a degree of vulcanization as a function of time and temperature is measured by the rheometer. A vulcanization curve or rheometric curve is represented by the graph of the torque curve on the rotor as a function of time.

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