Induction Sealing: An Excellent Choice For Tamper Evidence In Food Packaging

By Ryan Schuelke, VP of Sales, Enercon Industries

Induction sealing is a non-contact heating process that welds a foil laminate — called an inner-seal — to the lip of jars and bottles. The sealing process takes place after the filling and capping operation. Capped containers pass under an induction cap sealer mounted over a conveyor. The FDA recognizes induction sealing as an effective means of tamper evidence.

The standard system has two main components, the power supply and the sealing head. The power supply is an electrical generator operating at medium to high frequencies. The sealing head is a plastic case that houses a conductor formed into an inductive coil. When energized by the power supply, the head produces an electromagnetic current, called an eddy currently. When capped, the bottles enter this electromagnetic current, the foil of the inner-seal generates electrical resistance, heating the foil. The hot foil in turn melts the polymer coating on the inner-seal. The heat, coupled with the pressure of the cap, causes the inner-seal to bond to the lip of the container. The result is a hermetic seal.

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