Biaxially oriented multilayer barrier films

摘要

Films having a core of ethylene-vinyl alcohol copolymer (EVOH) sandwiched between polyolefin, e.g. polypropylene are coextruded so that the polyolefin also surrounds the EVOH layer on the side edges. The films, which can contain adhesive layers are oriented to a deformation ratio which is from greater than 4 in the machine direction and to a deformation ratio which is from greater than 7 in the transverse direction to give excellent oxygen and moisture barrier properties.