Infrared welding process for bonding portions of a vehicle interior assembly

A method of manufacturing a vehicle interior assembly (16). The method includes attaching a scrim (28) to a polyurethane substrate (26). The method also includes disposing a polypropylene material (24) directly on the scrim (28). The method includes applying infrared energy (30) to the polypropylene material (24) to bond the polypropylene material (24) to the scrim (28).