초록 ▼

This relates to an apparatus for heat bonding a lid having a metallic layer to a plastic container. The container, filled with a product, is seated in a nest and a lid is seated in place thereon. There is at least one corner on the lid and projecting from that corner is a pull tab. An induction heat

This relates to an apparatus for heat bonding a lid having a metallic layer to a plastic container. The container, filled with a product, is seated in a nest and a lid is seated in place thereon. There is at least one corner on the lid and projecting from that corner is a pull tab. An induction heating unit is associated with the lid and presses it tightly against the container while inducing electrical energy under controlled conditions into the metal layer. The induction heating unit is provided with a specific arrangement of ferrite members for controlling the induction of current into the metallic layer. The ferrite parts in conjunction with the induction coil serve to concentrate the induced electrical energy into substantial alignment with the induction coil notwithstanding the fact that there is a corner and there is projecting from the corner of the lid a pull tab.

대표청구항 ▼

An induction heating unit for heat bonding a lid or the like having a metallic layer to a container or the like wherein a resultant line of heat bond includes at least one corner, said unit comprising an induction coil having a loop configuration in accordance with the outline of said resultant line

An induction heating unit for heat bonding a lid or the like having a metallic layer to a container or the like wherein a resultant line of heat bond includes at least one corner, said unit comprising an induction coil having a loop configuration in accordance with the outline of said resultant line of heat bond and including at least one corner, said induction coil having a lid engaging face, a ferrite current concentrator positioned alongside said induction coil for concentrating induced current in a lid or the like metallic layer to substantially the outline of said induction coil, and a ferrite current concentrator unit at said one corner.