High Frequency Induction Cap Sealing

High Frequency Induction Cap Sealing With IGBT heating units Objective To heat an aluminum foil inside a plastic shampoo cap for sealing Material 2.0” diameter, plastic flip top cap, with a 0.9” diameter aluminum foil seal Temperature 250 - 300 ºF (120 – 150 °C) Frequency 225 kHz Equipment DW-UHF-7.5 kW, induction heating system, equipped with a remote heat station containing two 1.5 μF capacitors (total capacitance 0.75 μF). An induction heating coil designed and developed specifically for this application. Process A three-turn two-position helical coil is used to heat the aluminum foil in a tunnel style assembly. Product (containers) passes easily under the induction coil. The assembly is located such that the entire perimeter of the aluminum foil is heated uniformly. The container and cap is placed under the coil and RF power delivered for 0.12 seconds. The aluminum foil heats and seals to the plastic of the cap. Results/Benefits This induction heating configuration fulfills the process requirements and: • uses a simple, economical coil design • increases throughput with a dual-position coil • delivers quality, consistent seals • offers a repeatable process, well-suited for automation