The Effect of Screw Configuration on Residence Time in Continuous Devulcanization of NR/SBR Mixture by Twin-Screw Extruder

The accumulation of polymer waste in the environment is a threat to human life and other organisms on Earth. And it causes the necessity of recycling them. In this paper, a co-rotating twin-screw extruder was used to devulcanize the NR/SBR rubber compound. Then, the residence time was examined based on the different screw configurations and various angles of the kneading blocks. For this purpose, kneading elements were designed with different angles and set in the extruder. In the following, considering the extruder as a continuous reactor, equations and models for residence time and other parameters were defined. by studying solid and liquid (melt) models; It was found that the residence time is only affected by the spiral arrangement in the liquid part. This research aims to finding the optimal arrangement and angles to reduce the residence time, which improves quality and reduces energy consumption.