| 摘要 |
<p>Induction heating coil (34) of a single turn construction and particularly configurated for inducing electrical energy into a metal foil barrier layer of a laminated container closure for effecting heat bonding of the closure to a container in a preselected seal pattern. The seal pattern contains either one corner or the closure is provided with a projecting pull tab wherein there is a greater heating requirement and thus a requirement for the induction of higher electrical energy into the closure. The need for the induction of a greater amount of heat into the closure at a corner or the location of a projecting pull tab is provided for by reducing the cross section of the heating coil at the location of the greater heat requirement. The reduction in cross section is primarily effected by forming a notch (42, 44, 46, 48) in the heating coil. If desired, a closer control of the heating effect of the coil may be obtained by positioning in the notch a ferrite insert.</p> |
