摘要 |
A corrugated paperboard, manufactured with a layer of plastic film approximately 1-3 mil thickness, is laminated to the single face liner of single face board in the double-backer. The board has good moisture vapor transmission (MVT) properties for packaging food and chemical products. The film is supplied in roll form and reeved over a dewrinkling roll device to smooth it, then fed onto the single face liner as the single face corrugated is fed into the nip of the double-backer. The lamination of the film is made by the residual heat from the paper and pressure of the double-backer belt in the drying section of the corrugator without adding adhesives or other compounds. The film is a thermoplastic co-extruded polymeric film, e.g. high density polyethylene (HDPE), polypropylene, PET, having a heat seal layer thereon of a copolymer of olefin with Alpha-Beta monoethylenically unsaturated monomer, e.g., ethylene acrylic acid (EAA). The film surface of the manufactured board may be optionally treated with Corona discharge or high velocity flame treatment to oxidize the surface to enhance adhesive bonding in later prepared cartons made from the board. The process is applicable to single wall or multiwall corrugated paperboard in making a vapor barrier product having good MVTR. |