COMPUTER CONTROL OF INTERNAL MIXERS FOR MORE CONSISTENT EPDM COMPOUNDS

In this paper we show that computer usage not only improves the reprod ucibility of the mixing cycle, but also by monitoring the rotor speed and the thermal exchanges, the mixing becomes more consistent. For an EPDM with a bimodal molecular weight distribution, a high green streng th and a fast carbon black dispersion, we have used advanced control o f the mixing energy to show how the batch to batch reproducibility of a 70 Shore A compound is improved. It results in reducing the compound Mooney viscosity variation to less than that of the EPDM raw material . Therefore a tighter control of the rheology of the different mixed b atches is obtained. This leads to better productivity by more consiste nt extrusion and lower scrap level.