Technological watch

Polyurethane (PU) foams are used in various automotive applications due to their low cost and weight and highly tunable mechanical and physical properties. This article explores the effect of adding recycled thermoplastic elastomer (TPE) and recycled thermoplastic polyurethane (TPU) powder collected from 3D printing waste as filler material on thermal stability and mechanical, physical, and sound absorption properties of flexible PU foam. The incorporation of TPE powder at low filler content, 2.5?wt%, increased the compression modulus by over 140%, tear resistance by over 25%, and Young's Modulus by 50% compared to the control. The addition of 2.5?wt% TPU powder increased the compression modulus by 61%, tear resistance by 31%, and Young's Modulus by 84%. The addition of TPU powder at 2.5?wt% showed improvement in sound absorption of plane waves (up to 20% at 2500?Hz) for a frequency range of 50–3500?Hz. Adding an additive manufacturing waste stream into PU foam as a filler reduced waste to landfill and created a superior foam product. This article exemplifies the benefits of creating a closed?loop plastic industry to improve polymer materials and protect the earth.