Written by Kerryn Caulfield, Executive Director, Composites Australia Inc.
Like advanced composites used in industrial applications, the components of athletic footwear work together, bonded and layered to provide specific functions. Materials found in modern athletic shoes are formed, laminated, welded, blow-moulded, poured, woven and fused to create a seamless product that performs under stress.
Common materials used in athletic shoes include; Polyester, Nylon, Spandex, synthetic leather, Microfibre suede, TPR (Thermoplastic Rubber), Surlyn/Ionomer resin, Thermoplastic Polyurethane (TPU), EVA (Ethylene Vinyl Acetate), PU (Polyurethane), rubber – regular, blown, and carbon-infused
These materials serve various purposes, from the flexibility and support provided by TPU and EVA in midsoles to the durability of synthetic leather and nylon in the uppers. Athletic shoes also use specialised resins like Surlyn for added structure and resilience.
The Australian market for athletic footwear is driven entirely by imports. According to the Australian Bureau of Statistics, close to 41 million pairs of athletic shoes were imported during the 2023-24 financial year, equating to approximately 13,100 40-foot shipping containers. With no domestic production, Australia relies heavily on global supply chains for its athletic footwear needs.
While recycling and take-back programs have gained inspiring traction in recent years, aimed at giving shoes a second life, the reality is that most discarded shoes are still destined for landfill. The complex combination of materials in athletic footwear makes recycling a challenge, often leading to limited success in sustainable recovery efforts.
Parallel to FRP and CFRP, athletic footwear is a composite of carefully selected materials engineered for performance. While the ecological impact of limited recycling solutions remains a concern, do we choose to reduce consumption?
