?Polyethylene air-cushion film (also called polyethylene bubble film), which is divided into two kind: ordinary polyethylene air-cushion film and composite polyethylene air-cushion film, is a kind of packing material which has been widely used at present. Tt not only has good cushioning effect, shock resistance and heat-sealing performance, but also has such advantages as good corrosion resistance and transparency, etc. so it has been widely used for packing, household wares, post parcel, prcise instrument, bicycle, polyurethane furniture, etc.