HDPE is the high density version of PE plastic. It is harder, stronger and a little heavier than LDPE, but less ductile. Dishwasher safe. HDPE is lighter than water, and can be moulded, machined, and joined together using welding (difficult to glue). The appearance is wax-like, lustreless and opaque. The use of UV-stabilizators (carbon black) improves its weather resistance but turns it black. Some types can be used in contact with food.