Properties of Recycled and Modified Materials from Polypropylene Components in Vehicle

After crushing twice and screening, polypropylene components in end-of-life vehicles were two-stage separated and purified by high-voltage corona-electrostatic separation technique, and the separation technique was optimized. The purified polypropylene materials were modified by the modifier composed of 50wt% 8303K polypropylene, 30wt% 7467 polyolefin elastomer, 3.5wt% KH-560 coupling agent, 3.5wt% polyethylene wax, etc., and were injection molded. The mechanical properties and physical and chemical properties of the materials before and after modification were studied. The results show that after crushing and screening, the materials with particle size below 1.25 mm mainly consisted of rod-sheet-like polypropylene and contained few glass fibers, plastic powders and peeled copper wires. In the process of separation and purification, with the rotation speed of the first roller of 114 r·min^-1 and the second roller of 33 r·min^-1, about 78wt% polypropylene materials were obtained, and over 13wt% metallic materials were separated. The mechanical properties of the purified polypropylene were improved after modification, meeting the requirements of automobile manufacturers.