Induction sealing is the process of bonding thermoplastic materials by induction heating. This involves controlled heating an electrically conducting object (usually aluminum foil) by electromagnetic induction, through heat generated in the object by eddy currents.
Induction sealing is used in many types of manufacturing. In packaging, it is used for package fabrication such as forming tubes from flexible materials, attaching plastic closures to package forms, etc. Perhaps the most common use of induction sealing is cap sealing, a non-contact method of heating an inner seal[1][2] to hermetically seal the top of plastic and glass containers. This sealing process takes place after the container has been filled and capped.[3]
- ^ US 2715474 A, Phillips, "Closure liners and methods", published 1955
- ^ US 4778698 A, Ou-Yang, "Innerseal for container for use with liquid contents", published 1988
- ^ US 2937481 A, Jack Palmer, "Method of producing a package", published 1958