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AssigneeNational Can Corporation
InventorsH. Harald Lutzmann, Paul D. Frayer
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Two or more chemically dissimilar and non-compatible films may be bonded together to form a composite sheet by simultaneously subjecting them to high voltage electric corona discharge of selected intensity continuously through a critical region of mutual contact of the films. The critical region begins at the point at which the film surfaces to be bonded are not in contact with one another and extends at least to the point where all the films to be bonded are in mutual contact with their adjacent films. A preferred film suitable for use as a wrapping material and obtained by the process of the invention comprises at least one layer of a polyolefin film and at least one layer of a film containing an acrylonitrile polymer.
A method of laminating two or more sheets together comprising the steps of
A method of bonding at least two chemically dissimilar sheets one to the other to form a laminate without an adhesive material interposed therebetween, at least one of said sheets being a plastic sheet, said sheets having surfaces to be bonded to each other and comprising materials whose bonding compatibility to each other is enhanced by electrical corona discharge treatment of at least one of said sheet surfaces, said method comprising (a) introducing said sheets in air into a visible alternating current corona discharge zone between a pair of electrode members one of which is a grounded film support member with said sheet surfaces spaced one from the other, (b) contacting the sheet surfaces to each other within said corona discharge zone and (c) maintaining the visible alternating current corona discharge in the wedge shaped divergence defined between the surfaces of adjacent sheets extending from the line of contact in the direction opposite to the direction of movement of the sheets to where the sheets are spaced apart.
Apparatus for laminating at least two chemically dissimilar sheets one to the other to form a laminate comprising
Dependencies are inferred from the claim text.