| 摘要 |
A method and apparatus for attaching a skirted end closure to a tubular paperboard container, the container having a continuous lapped seam from one end to the other. The interior surface of the container is layered with a thermoplastic, and the container wall includes a layer of metal foil. An annular induction coil is placed near the annular surface of contact between the end closure skirt and an end region of the container interior surface. Upon activation of the induction coil, the metal foil is heated by the usual eddy current effect, to thus soften the thermoplastic and adhere the end closure skirt to the container. The specific improvement in this combination is the addition to the coil of a field intensifier in the region of the lapped seam. The action of the intensifier partially overcomes the lessened heating effect which naturally occurs at the ends of the lapped seam. |
