Laminating method

Claim 1

A method for preparing a heat sealed, dry, laminated product of at least four ply wherein the first ply is a substrate layer, the second ply is a thin extruded film-forming plastic material made of a dissimilar plastic material relative to the first ply and having a thickness as small as about 1/6 mil, the third ply is a material layer made of dissimilar material relative to the second ply, and the fourth ply is a plastic material layer having a treated surface, said fourth ply being made of a dissimilar material relative to the third ply, said treated surface being formed by flame treatment or electronic treatment, said method comprising the steps of: preheating at least one of said third and fourth plies to a temperature between about 140°F and about 450°F in order to assist same in bonding to one another, heating said film-forming plastic material to form a hot extruded film-forming plastic material of sufficiently elevated temperature such that it will generally help cause a heat sealed bond between the third and fourth ply materials, bringing the substrate layer into firm contact with the hot extruded film-forming plastic material between a pair of moving surfaces, preventing the plies from contacting one another substantially until they are brought together between the moving surfaces, essentially simultaneously bringing the third ply layer into firm contact between said moving surfaces with the extruded film-forming plastic material whereby said extruded material effectively bonds the first ply to the third ply, and essentially simultaneously bringing the fourth ply plastic material into firm contact between said moving surfaces such that said surface thereof is in contact with the third ply, thus producing a heat sealed bond between the third and fourth ply due in substantial part to the heat generated by the hot extruded plastic material and also due in part to said preheating.

Claim 2

A method for preparing a heat sealed, dry, laminated product of at least four ply wherein the first ply is a substrate layer, the second ply is a thin extruded film-forming plastic material made of a dissimilar plastic material relative to the first ply and having a thickness as small as about 1/6 mil, the third ply is a material layer made of dissimilar material relative to the second ply, and the fourth ply is a plastic material layer having a treated surface, said fourth ply being made of a dissimilar material relative to the third ply, said treated surface being formed by flame treatment or electronic treatment, said method comprising the steps of: preheating at least one of said third and fourth plies to a temperature between about 140°F and about 450°F in order to assist same in bonding to one another, heating said film-forming plastic material to form a hot extruded film-forming plastic material of sufficiently elevated temperature such that it will generally help cause a heat sealed bond between the third and fourth ply materials, bringing the substrate layer into firm contact with the hot extruded film-forming plastic material between a pair of moving surfaces, preventing the plies from contacting one another substantially until they are brought together between the moving surfaces, essentially simultaneously bringing the third ply layer into firm contact between said moving surfaces with the extruded film-forming plastic material whereby said extruded material effectively bonds the first ply to the third ply, and essentially simultaneously bringing the fourth ply plastic material into firm contact between said moving surfaces such that said surface thereof is in contact with the third ply, thus producing a heat sealed bond between the third and fourth ply due in substantial part to the heat generated by the hot extruded plastic material and also due in part to said preheating.