MATERIALS | POLYOLEFINS


Right: Constantia and Watttron have devised a system to seal both PP and aluminium lids


behaviour and good sealing performance. It uses several ExxonMobil polymers, including Exceed Tough+ m 0512.RA, EVA 06519FL and Exceed Flow m 1020.RA. The film was extruded on


Bandera’s barrier blown film line, crosslinked via e-beam and is compatible with blown and tubular quench extrusion. VSP is becoming more popular in meat and food packaging as its transparent films allow the packaged product to be inspected from all sides. Thanks to high puncture resistance and optimal sealing behaviour, the film helps to ensure packaging integrity and provide product protection. The new film claims to offer cost savings (by


replacing ionomers), maintain sealing properties, provide high toughness (to protect sharp food items) and allow high clarity for consumer appeal. “This was an opportunity to showcase both cost savings and high performance,” said Diego Castiglioni, technical director at Bandera.


Sealing the deal Constantia Flexibles has teamed up with thermal technology specialist Watttron to develop a new technique that enables both polypropylene (PP) and aluminium lids to be sealed on PP cups using a single system. This builds on Constantia’s PPCover, a mono-


material PP lidding designed to meet recyclability standards without affecting performance. Integrating PPCover into existing sealing machines presented a technical challenge – ensuring consistent, high-quality seals across different lid materials without introducing inefficiencies or material deformation. Traditional sealing systems typically heat the


entire sealing head, which can cause issues such as curling due to excess heat exposure. This prompted Constantia to explore more precise and adaptable sealing methods – in this case, Watttron’s ring-heating technology which applies heat only to the outer sealing ring. This targeted method reduces thermal stress on the lid material and improves energy efficiency. The system heats and cools rapidly—typically at a


rate of 10 to 20 °C per second—and maintains the set temperature with a high degree of accuracy (±1 °C). These features not only support consistent sealing performance but also allow the system to be safely powered down during production stops,


26 FILM & SHEET EXTRUSION | January/February 2026


contributing to energy savings of up to 50% compared to conventional sealing methods.


Lab-scale tests using PPCover demonstrated good peel behaviour, strong internal


pressure resistance and reliable sealing for both PP and aluminium


lids. “We developed our ring-heating technology to deliver precise energy exactly where it’s needed,” said Marcus


IMAGE:


CONSTANTIA FLEXIBLES


Stein, CEO of Watttron. The universal sealing technology offers several advantages: it cuts the need for


separate machines or setups for different lid materials; simplifies production processes; and reduces equipment complexity. Claus Dworschak, market product manager for die cut lids at Constantia, added: “This simplifies operations and enhances quality – which is exactly what our customers need.” Last year, as part of its growth strategy,


Constantia acquired Aluflexpack, which it says increases its footprint in high-value segments – especially the food and pharmaceutical industries. “This is not just about growth, but about creating


an agile, future-ready packaging network that serves our customers with greater speed,” said Marc Rademacher, EVP for consumer commercial at Constantia. “We look forward to joining forces with the


Aluflexpack team to complete the integration of the businesses,” he added.


CLICK ON THE LINKS FOR MORE INFORMATION: � www.totalenergies.com � www.wh.group � www.masterpress.com � www.dow.com � www.macchi.it � www.itp.it � www.sml.at � www.novachemicals.com � www.borealisgroup.com � www.borouge.com � www.oq.com � www.wiskunststoffe.de � www.amiplastics.com � www.synthomer.com � www.kpfilms.com � www.innoviafilms.com � www.exxonmobilchemical.com � www.cflex.com � www.watttron.com


www.filmandsheet.com


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