Recycling of Cross-linked Polyethylene Cable Waste via Particulate Infusion

Abstract

The amount of plastic waste is on the rise each year. It is associated with green house gas emissions and hazardous potential if left untreated at the landfill. Plastic is formed from the polymerization of ethane, essentially fossil fuel based, and with chemical energy content equivalent to diesel fuel, i.e. 43 MJ/kg. Thereby, plastics are excellent candidates/feedstock for energy recovery. This work explores the recycling of cross-linked polyethylene waste-plastic that is generated at a considerable amount from the cable industry. It undertakes thermal analysis of the plastic as the first step using the Differential Scanning Calorimetry (DSC) to observe its thermal conversion and meting temperature. It also undertakes the re-compounding of the waste plastic by infusion the cross-linked polyethylene waste into mini-compounder at different waste-to-virgin polyethylene weight ratio, i. e. 5%, 10%, and 15%. Assessment of the mechanical properties of the compounded product, i.e. recycled mixture, is conducted on standard uniaxial samples using thermo scientific mini extruder, the HAAKE MiniJet II injection molding, and Instron tensile machine. At as high as 15 wt% recyclate to virgin mixture, an increase of 17% in young modulus, 37.2% in yield stress, 22.4% in ultimate stress, and a decrease of 3.3% in the melting point were obtained compared to the virgin/baseline polyethylene. From the resulted stress strain relation Morz bilinear plastic material model constants obtained (Et), that showed 25.6% increase, allowing better investigation of the true stress/strain behavior through FEM numerically simulation.