Process for the recovery and devulcanization of cross-linked rubber

Abstract

A process for recovery and devulcanization of vulcanized rubber is provided. The process takes place in a plant including a mill for grinding vulcanized rubber into particles, a twin-screw extruder provided with a device for forced feeding of vulcanized rubber particles and a thermostatting device, a single-screw extruder arranged downstream of the twin-screw extruder and equipped with a thermostatting device, a filter for devulcanized rubber and an extrusion die shaped like a slot, from the which devulcanized rubber comes out in the form of a strip or sheet, and a cooling device for the devulcanized rubber strip or sheet. The twin-screw extruder operates at a temperature between 35 and 450° C., with a rotation speed of the screws between 15 and 600 rpm, and a torque density between 11 and 18 Nm/cm3, so that the shear rate remains constant for the entire longitudinal extension of the twin-screw extruder.

Dependencies are inferred from the claim text.