| 摘要 |
<p>A container closure (54) formed from a thermoplastic polyolefin, e.g. polypropylene, which has been molded and adheres simultaneously to a coated foil, e.g. an aluminum insert (10), to which a conventional plastisol gasketing compound (60) may be adhered to provide a hermetic container seal under hot fill and retort conditions. In order to facilitate adhesion to both the polypropylene closure panel and the PVC plastisol gasketing compound, a dead soft aluminum foil web (12) was first coated on one side with an organosol (16) utilizing a gravure coater (14), after which the coated web was passed through an oven (22). The partially coated web was then coated with a primer dispersion (24) again utilizing a gravure coater (26), after which the coated web was passed through a second oven (32). A layer of polypropylene homopolymer (34) was applied to the primer and inserts were die cut from the resultant web. The inserts were incorporated in a closure injection molding apparatus and a plastic closure (54) injection molded thereabout. Thereafter a plastisol gasket compound (60) was applied to the exposed surface of the insert (10) and fused by convection and/or induction or dielectric heat.</p> |
