Mechanical recycling of PVC plastic waste streams from cable industry: A case study

Abstract

Plastics draw a paramount amount of fossil fuel reaching nearly 300 million tons annually and continue to enter every production sector of our lives (automotive, aerospace, packaging, building, toys, furniture, clothing, medical etc.). While different from polyolefin, Poly Vinyl Chloride (PVC), along with many halogenated polymers, all belong to the same thermo-plastic group. Rigid plasticized PVC is commonly used in pipes, window framing, floor coverings, roofing sheets, and cables; thereby it is discarded at a high rate. Adopting an appropriate recycling pathway is of both an economic value and an environmental benefit. The high hydrogen chloride content and the concern of dioxins and furans emission deter its thermochemical conversion. Re-compounding, particularly, when it is generated at a substantial amount and at low variation in composition, is the ultimate recycling strategy. In this work, analysis of the composition of PVC waste stream from the cable industry is carried out. Thermal Gravimetric Analysis (TGA) was conducted to infer the moisture, volatile, and inorganic filler fractions and the extent of thermal stability. These data are important to design the proper re-compounding, extrusion and injection conditions for the postconsumer PVC. Standard tensile and dynamic stress samples were produced and subjected to successive aging, extrusion and molding. Thermal properties were insignificantly altered, whereas mechanical properties lost some but tolerable flexibility. The results suggesting that PVC cable polymer can be reutilized in a close sustainable manufacturing which warrants ecological and economic benefit.