Extrusion rate, carbon black

In the carbon black industry we talk about carbon blacks in relations to adhesion to steel belts, better abrasion resistance, different traction, changed hysteresis requirements, different flexural properties, different extrusion rates and properties, hardness, and on ad infinitum, and all in new rubber compounds with different synergistic effects or loss of synergism as the case may be with changes in ingredients. Carbon black has traditionally been manufactured by those skilled in the "art", so as soon as a product is defined it can fairly quickly be matched. But, how is the first major product change to be made, and for what specific objectives ... 

To relate the physical properties of carbon black to rubber properties, we tested these tread blacks in the ASTM natural rubber recipe and in an SBR 1500 test recipe. In both elastomers, we checked standard stress/strain properties of modulus, tensile strength, and hardness. In the natural rubber recipe we also tested Firestone running temperature and rebound, and Goodyear rebound. In the SBR we checked percent swell, extrusion rate, viscosity, and laboratory abrasion. 

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