Induction Seal Coil and Method

An induction seal coil assembly for sealing a generally disc-shaped metal end having a central portion and a peripheral portion with a rim configured to receive an end of a generally cylindrical plastic body, the induction seal coil assembly comprising:

• a generally annular electrical conductor having an internal channel and being sized to extend substantially along the extent of and adjacent to the rim of the metal end, the electrical conductor being discontinuous at a gap to form an electrical circuit;
• connectors for coupling the electrical conductor to a source of radio frequency electrical current;
• and
• an alignment feature on the electrical conductor for aligning the conductor with the rim of a metal end when the electrical conductor is brought in proximity with the metal end.

A method of sealing a metal end having a peripheral portion and a central portion to a non-metal body of a container comprising the steps of:

• (a) positioning the metal end on the non-metal body with peripheral portion of the metal end engaging an end of the non-metal body;
• (b) inducing alternating electrical currents in the peripheral portion of the metal end sufficient to heat the peripheral portion while not heating the central portion of the end;
• (c) maintaining the induced electrical currents for a time sufficient to melt the end of the non-metal body in engagement with the peripheral portion of the metal end;
• and
• (d) ceasing inducement of electrical currents in the peripheral portion of the metal end and allowing the melted portion of the non-metal body to solidify to form a bond and a seal with the metal end.