High Quality Content by WIKIPEDIA articles! Zytel is a trademark owned by DuPont and used for a number of different high strength, abrasion and impact resistant thermoplastic polyamide formulations of the family more commonly known as nylon, often with varying degrees of fiberglass, from 13% to 60%, added in for additional stiffness. Some of the grades are homopolymer nylon66, other copolymers with nylon6 repeat units, and further grades involving rubber toughening are available. Many grades are based on polyphthalamide (PPA), another common polyamide.