Patent ID: 7220948

Claim:
A method of producing a seam in a substrate or between two or more substrates using induction which method comprises the steps of: (a) placing an induction activatable seaming tape at the point where the seam is to be formed, said seaming tape comprising a base layer, a susceptor overlying all or a substantial portion of the base layer and capable of generating heat upon exposure to electromagnetic energy, and a heat activatable adhesive layer in heat transfer relationship with said susceptor and overlying all or a substantial portion of said susceptor layer, but in any event overlying a centerline of the seaming tape, the centerline of the seaming tape running the length of the tape; said adhesive layer in contact with the substrate, (b) placing an induction tool having a double racetrack induction coil comprising two coil loops, in a side-by-side, substantially coplanar relationship, over the point where the seam is to be formed whereby the axis of the induction tool which is defined as the centerline running between the two coil loops and along the length of each opposing each of the coil loops, is parallel to and substantially centered over the centerline of the tape; (c) activating the induction coil for sufficient time to generate sufficient heat in the susceptor to heat the adhesive above that temperature needed to activate the adhesive; and (d) allowing the adhesive to cool thereby bonding the seaming tape to the substrate or substrates; wherein all the edges of both coil loops lie substantially in the same plane.