High Density Polyethylene Sheet: 2mm to 8mm thick. On this page you can buy High Density Polyethylene, also referred to as HDPE or PE300, in full sheets in 2mm, m, 4mm, 5mm, 6mm and 8mm thick. Product Availability. normally from stock; Also available in a sheet size of 3000mm x 1500mm: please ntact us to discuss your requirements