Recycling Crosslinked Polyethylene (XLPE)
Because of its outstanding dielectric properties and heat resistance, crosslinked polyethylene (XLPE) is widely used as insulation materials for electric wires and cables. However the three-dimensional lattice structure produced by crosslinking makes it impossible to melt it down again for molding. Thus almost all waste XLPE is currently burnt (as a fuel) or disposed of in landfills. However by heating and shearing meltable polyethylene suitable for recycling can be produced. (RDC 7/14/2011) (Tokuda et al, Furukawa Company, 7/14/2011)
Recent Journal Articles
Morphological and structural development of recycled crosslinked polyethylene during solid-state mechanochemical milling
(257–264)Journal of Applied Polymer Science 122 #1 (2011)
Wu, Liang and Lu ofSichuan University, China, partially decrosslinked waste crosslinked polyethylene (XLPE) to obtain a thermoplastic recycled material through solid-state mechanochemical milling with pan-mill equipment at ambient temperature. The gel fraction and size exclusion chromatography measurements showed that the gel content of XLPE decreased remarkably with increasing cycles of mechanochemical milling, whereas the molecular weight of the sol fraction was not significantly reduced; this indicated the realization of partial decrosslinking during mechanochemical milling. Differential scanning calorimetry and X-ray diffraction analysis showed that the melting temperature of decrosslinked polyethylene increased by 3.5°C because the bigger crystallites size resulting from the higher mobility of the chain segment. The mechanical properties of recycled XLPE also achieved significant improvement after mechanochemical milling. Solid-state mechanochemical milling is a cost-effective, reliable, and environmentally friendly method for recycling XLPE at ambient temperature without any additional materials or chemicals. (RDC 7/13/2011)