Synthetic thermoplastic of the polyamide family. It may be melt extruded into filaments useful for carpet yarn. Nylon is by far the dominant fibre in tufted carpet pile yarns. Two chemical types, nylon-6,6 and nylon-6, are used in carpet. Nylon-6,6 is poly (hex- amethyleneadipamide) and nylon-6 is polycaprolactam.