Constantia Flexibles, together with thermal technology specialist Watttron, has presented a new sealing solution. The system makes it possible to reliably seal both polypropylene and aluminium lids on PP cups with a single system.
The cooperation addresses a key challenge in food packaging: the compatibility of sustainable materials with efficient production. The basis is the PPCover developed by Constantia Flexibles, a mono-material PP lid that fulfils recycling standards but places high demands on the seal.
Precise heating for stable sealing quality
Conventional systems heat the entire sealing head, which can lead to material deformation. The ring heating technology developed by Watttron, on the other hand, only directs heat to the outer sealing ring. This reduces the thermal load and increases energy efficiency. The system achieves heating and cooling rates of 10 to 20 °C per second and maintains temperatures with an accuracy of ± 1 °C. According to the company, this enables energy savings of up to 50 % compared to conventional processes.
Laboratory tests with PPCover showed high pressure resistance, reliable seals and consistent peel behaviour - for both PP and aluminium lids. Marcus Stein, CEO of Watttron, explained: „We have developed our ring heating technology to utilise energy exactly where it is needed - no more and no less.“
Simplified processes and quality control
The system does not require separate machines or conversions for different lid materials and can be combined with inspection systems that detect faulty cups in real time. Claus Dworschak, Market Product Manager Die Cut Lids at Constantia Flexibles, described the technology as a „strong one-fits-all solution for lids in the dairy sector“, which simplifies processes and improves product quality.
Source: Constantia Flexibles
