OPP plastic bags are stretchable polypropylene, easy to burn, melt, drip, yellow, blue, leave less smoke, and continue to burn. OPP material is the most brittle, the highest transparency, tension is not enough, but the most explosive mouth. And the printing of the most easily bleaching. PE is made up of ethylene and is divided into high-density polyethylene, medium density polyethylene and low-density polyethylene according to the density. PE body soft, but not enough transparency, other materials higher, more meng. Good pull! Non explosive mouth.