1. The ratio of nitrogen-adsorption on the carbon black surface is recommendatory test index.
2. 300% Stretching Stress is to get the carbon black disparity between the everyday carbon black (SRB3#) sample and the standard in the same experimental situation, with I type and dumbbell type reamer set by GB/T528. The vulcanization of the carbon black lasts 30 minutes under the average temperature of (145±1) .
3. All the technical indicators are taken as that of qualified products.