all Engineered plastic Optical raw material Alloy General purpose Others Engineered plastic EVOH Ethylene-vinyl alcohol PEI Polyether imide PAI Polyamide imide PET-G Glycol-modified polyethylene terephthalate PEEK Polyether ether ketone PSU Polysulfone PPS Polyphenylene sulfide PPA Polyphthalamide POM Polyoxymethylene (polyacetal) PES Polyether sulfone