Moving Die Rheometer

Introduction

Moving Die Rheometer(MDR) is a testing equipment which analysis the cure characteristics of Rubber Compound & monitors the processing characteristics as well as physical properties of the material. It is based upon international technology. It is the only instrument in the rubber industry which helps to choose right ingredients and its appropriate dose to meet the end products "Rishikesh make" Moving Die Rheometer is a Rotor less Instrument in which Die oscillate and measures the change in stiffness of rubber compound compressed between two heated dies. The MDR generates 3 curves S', S" and Tan Delta.The MDR produces a cure curve labeled S' which is similar to the ODR curve.

Definition of S' and S"

S' is called the storage modules ,elastic modulus or in phase modulus. S" is called the loss modulus, viscous modulus, or out-of-phase modulus. All of these terms have been used to mean the same thing. The unit of S' and S" in the product family instruments are in lbs. These are units of torque. They can also be in dnm. Which are also torque units.

Tan Delta 

The Tan(Delta) is computed from the ratio S"/S' or loss of modulus divided by storage modulus. The smaller the Tan delta, then the more viscous the material.

Application of S"

There have been many research articles which discuss the benefits of using S"(Loss modulus) or Tan (Delta). A relationship may exists between dynamic properties and processability (e.g. die swell) of uncured compound. After cure, the loss modulus can indicate whether a compound will meet some special application. For example, the rubber used in an automotive engine mount should have high Tan(Delta). S" in order to dampen vibration. On the other hand, the compound used in a rubber band needs a low Tan Delta .