Performance optimization of a counter rotating twin screw extruder for recycling natural rubber vulcanizates using response surface methodology

Response surface methodology has been used to predict the optimal processing parameters, viz. barrel temperature and screw speed. for devulcanization of natural rubber based waste rubber powder in a counter rotating twin screw extruder. Central composite rotatable design for two variables at five levels was chosen as the experimental design. The results obtained after measuring the responses were fitted as a two variable second order equation and the corresponding contour plots were plotted and analyzed. Optimum properties were predicted at 219 degreesC temperature and 20 rpm screw speed, which were also confirmed experimentally. (C) 2003 Published by Elsevier Ltd.