Polyethylene Plastic Sheets HNOKAY. High-Strength Slippery UHMWPolyethylene Sheets and Bars. mpared to our standard UHMW polyethylene, these sheets and bars hold up better to scuffs and scrapes in high- speed, high- precision, and high-impact applications— such as nveyor equipment, chute liners, and machine guards. Also known as Tivar HPV.