Investigation of the ageing behaviour of multiple reused polypropylene binding twines

Climate change is one of the significant challenges of the 21st century. To achieve climate goals a change in plastic waste management needs to be implemented. This research examines the potential of thermo-mechanical recycling of plastic waste, focusing on agricultural binding twines made from polypropylene. Old binding twines from agriculture were collected and recycled with a twin screw extruder. The ageing behaviour of the recyclate in terms of multiple recycling is examined in detail with tensile tests and melt volume rate measurements. The findings indicate a general degradation in mechanical properties and a decrease in viscosity due to molecular chain scission. Despite these degradations, the material remains processable, indicating the potential for continued recycling loops.