Induction seal improves seal quality and shelf-life for Nestle New Zealand’s Snap-on cap
When Amseal, Enercon’s local representative in New Zealand, brought in a sealing project for a non-round and non-threaded container it would have been easy for Enercon’s induction sealing experts to turn the project down. But instead they rolled their sleeves up and developed a custom solution for one of the world’s leading manufacturers: Nestlé of New Zealand.
Nestlé’s Cambria Park engineering team needed to improve seal quality and shelf life on PET containers with snap-on caps. Nestlé Project Engineer Greg Smith cites the key advantage in switching from heat sealing to induction is seal placement. The heatseal membrane was picked from a magazine and placed over the plastic containers and tacked on prior to sealing. Imperfect membrane placement and imperfect containers caused a faulty seal, resulting in reduced shelflife and product damage.
With induction, the liner is captured inside the plastic snap-on closure as the closure is applied. The cap’s non-round shape is challenging because induction currents typically run in a circular or oval pattern. Through proprietary design technology, Enercon’s engineers came up with a way to force the currents in a non-circular pattern. Of course this all had to be accomplished fast enough to keep pace with the two-up auger filler that cycles 21 times/min. That meant induction sealing would have to take place in 0.7 sec.
“The induction sealing system produces a far superior seal.” Nestle Project Engineer Greg Smith
The sealing heads also compensate for variations in the cap. They are fitted with a pad that results in more reliable sealing because it molds itself to slight imperfections in the cap.
The hermetic induction seal improves product shelf life.