Author(s)

B. Thomas, S. Martinez & M. Hadfield

Abstract

Polyurethane (PU) has been the primary material used in skateboard wheels since the 1970s. Since then PU wheels have been used on a wide range of scooters, trolleys and other applications. Polyurethane wheels offer a smoother ride, better grip with the pavement and improved abrasion resistance compared to previous wheel materials. However, the polyurethane used for these wheels cannot be easily recycled and with the dwindling resources and ever increasing laws governing waste recycling, maintenance of resources has become increasingly important. This makes it necessary to find new uses for recycled plastics, apart from the typical low-grade us es such as packaging and road filler that result from the uncertain material properties of recycled plastics. The friction and wear of recycled plastics are often less affected by the recycling process than other material properties; consequently it is decided to study the potential application of recycled plastic materials to replace polyurethane wheels. A range of common recycled plastics are selected. These materials are then examined using a modified Plint TE57 reciprocating tribometer in sliding over an asphalt surface, using these results to analyse their friction and wear performance compared to polyurethane. A new test rig design is developed and varied contact conditions are tested. Data obtained from the tests shows that recycled polycarbonate could be a suitable replacement for polyurethane in this case with similar friction and wear results detected. Sustainability considerations regarding the use of recycled plastics are also analysed, demonstrating the advantages of the use of recycled plastics to the environment, these include reducing the CO2 footprint by over 50%, the embedded energy consumed by 40% per wheel, and the economic material cost by 67%, among other benefits. Keywords: tribology, friction, recycled plastics, polyurethane, skate wheels.

Keywords

tribology, friction, recycled plastics, polyurethane, skate wheels