Recycling and reuse of waste artificial turf via solid-state shear milling technology

Abstract

Nowadays, the amount of the artificial turf waste is very huge, as it has been applied widely. However, it is a great challenge to recycle and reuse waste artificial turf (WAT) because its components are complex and hard to separate. In this study, solid-state shear milling (S³M) technology was introduced to recycle WAT into composite powder with valuable properties through ultrafine milling of WAT at room temperature. The results showed that the WAT included 46.7 wt% PE, 8.7 wt% PP, 2.4 wt% PET, 16.1 wt% polyacrylate and 26.1 wt% inorganic infill. The results of SEM and ultra-depth three-dimensional (3D) microscopy indicated that the domain size of the recycled material became smaller with the increase of milling cycles. The domain size and the performance of the recycled material could be controlled by the particle size and the size distribution of the composite powder in the solid state. The dynamic mechanical analysis (DMA) and X-ray diffraction (XRD) patterns demonstrated that the S³M technology improved the compatibility between the components and effectively decreased the crystallite size of PE in WAT. The melt flow index and the high capillary rheology test indicated that the thermal processability of the recycling material became better through S³M milling. The tensile strength and the elongation at break of the recycling material reached 12.6 MPa and 96.3%, respectively. What's more, low-price wood–plastic products with good performance and appearance could be manufactured using the recycled materials.