According to environmental expert, most non woven bags on the market are made of polypropylene, while traditional plastic bags are made of polyethylene. Although these two materials have similar name, they have totally distinct chemical constructions. Polyethylene’s chemical molecular construction has strong stability, extremely hard to degrade, so plastic bags cost 300 years to degrade completely. While polypropylene has unstable chemical construction, and fragile molecular chains, non woven bags can effectively degrade within 90 days. Besides, a non woven bag can be used over 10 times, but its pollution to the environment is only 10% of that of a plastic bag.