HDPE Sheets – Stress-Relieved (S/R) – HDPE Sheets – Stress . Sep 12, 2019 · HDPE (high-density polyethylene) sheets offer excellent impact resistance, light weight, low moisture HENAN OKAYorption, and high tensile strength. HDPE is also non-toxic and non-staining and meets FDA and USDA certification for food processing. Sheets Sold on this Page