Investigation of Continuous Process for Recycling of Silane Cross-Linked Polyethylene by Supercritical Alcohol

Abstract

We investigated a continuous process for recycling of silane cross-linked polyethylene by use of supercritical alcohol.
Conditions for the recycling silane cross-linked polyethylene to yield polyethylene were investigated by a batch process using an autoclave. It was found that the use of supercritical alcohol at around 10 MPa and 320°C was optimal for the plasticization of silane cross-linked polyethylene.
For the continuous process, twin-screw extruder was adopted, into which the supercritical alcohol was injected. As a result of the optimal reaction between silane cross-linked polyethylene and alcohol, the silane cross-linked polyethylene could be recycled at the speed of 8 kg/h. The recycled Polyethylene showed good mechanical properties and satisfied the standards for its use in the insulation of cable.
Thus the twin-screw extruder is potentially useful as a reactor for supercritical fluid.