| Due to a number of developments since its inception, induction sealing now offers greater productivity and control, and the ability to incorporate anti-tampering and anti-counterfeiting methods. Peter Tindale at Pillar Technologies breaks open the advantages over competing technologies
Induction sealing is a straightforward process used in the pharmaceutical packaging industry and many other technically demanding applications as a method of hermetically sealing containers with a foil laminate. The induction liner comprises an aluminium foil with a heatseal facing and other layers according to the requirements of the application. This is typically supplied already inserted into the closure. The torqued-down closure and container are then passed under an induction sealing head where an electromagnetic field induces a current into the foil which, in turn, generates heat. This is sufficient to melt the heat-seal layer on the underside of the foil, and form a strong bond.
The result is a truly hermetic seal, with excellent moisture and oxygen barrier properties, capable of providing secondary tamper evidence, extending product shelf-life and eliminating the risk of leakages. Perhaps just as importantly, this can be achieved quickly, simply and safely on plastic or glass containers at high line speeds – typically over 100 containers/minute – and without the need for any form of contact between the sealing head and the container.
THE BENEFITS OF INDUCTION
Adding induction sealing to an existing production line is inexpensive and offers a potentially rapid return on investment. In comparison with conduction sealing techniques, induction is a much more efficient and controlled process, with instant start-up. Unlike conduction, which uses a hot plate process, induction uses an electromagnetic field to generate heat so that ambient heat is minimised, helping to keep the sealing head at a cool temperature, improving operator safety and simultaneously offering a wider selection of lining materials to choose from. In addition, applications for conduction can be limited if the product to be packaged has particularly heat-sensitive constituents. |
