HDPE is a highly crystalline non-polar thermoplastic resin produced through the copolymerization of ethylene and a small amount of a-olefin monomer. HDPE is synthesized under low pressure. HDPE is mainly a linear molecular structure and has little branching. It can withstand high temperatures and has good rigidity and mechanical strength and anti-chemical corrosion. Although both materials are polyethylene, they do have different properties. LDPE is softer, more flexible and melts at a lower temperature than HDPE. Low density polyethylene, also known as high pressure polyethylene (LDPE). LDPE is used in sandwich bags and other types of packaging. HDPE is harder, has a higher chemical resistance and can withstand higher temperatures.