How functional coatings are driving the single-layer switch

Traditional flexible packaging has long relied on complex multi-layer laminates to safeguard product freshness. By binding dissimilar materials like PET, aluminum foil, and PE together, converters historically achieved excellent oxygen, moisture, and grease barriers.

But here's the catch: These mixed-material combinations create severe recycling challenges at the end of the packaging lifecycle, as the layers cannot be easily separated in standard mechanical recovery streams. This technical friction has forced a fundamental shift away from maximum performance at any cost toward design-for-recycling principles.The objective is structural simplification: reducing material complexity while maintaining strict shelf-life equivalence.
The solution is emerging through advanced chemistry that integrates barrier functionality directly onto recyclable polyolefin films.

By treating film surfaces with engineered polymer architectures, coating manufacturers are de-specifying traditional multi-layer setups and paving the way for all-PE or all-PP structures. This single-pass approach eliminates secondary lamination steps, lightweights the package, and ensures compliance with global extended producer responsibility frameworks.

Gilles Le Moigne, head of circular economy at Siegwerk, notes how this chemistry closes the historical performance gap on flexible lines. "By integrating advanced functional coatings for oxygen protection and thermal resistance, we enable mono-PE and mono-PP structures to match the barrier performance of traditional PET/PE or metallised materials. Le Moigne adds, “These advancements, combined with our deinking-compatible primers, ensure that brands can maintain product shelf life and machine efficiency while achieving full recyclability.”

Achieving this level of protection on a single substrate requires sophisticated formulation parameters. Curing kinetics and cross-linked polymer systems must be precisely tailored to control permeability and prevent substance migration. When these functional layers are integrated, mono-material structures can comfortably replicate the performance of legacy structures under real-world logistics stresses.

Paulo Vieira, packaging coatings and global key account technical director at Flint Group, details the structural science backing these developments. "The formulation science behind these coatings draws upon crosslinked polymer systems that provide controlled permeability and resistance to migration.” Vieria adds, “ This allows converters to achieve shelf-life equivalence with laminated films while using a single substrate. Material use is minimised, and packaging becomes easier to recycle.”

For converters running high-speed production lines between 400 and 600 m/min, this transition also optimises shop-floor economics. Applying a single, highly functional layer reduces raw material inventory, avoids costly secondary lamination steps, and lowers total operational waste.

Tapas Mandal, head of R&D and application development at Toppan Speciality Films, explains how film surfaces are being systematically re-engineered to match these requirements. "The industry is moving from a laminate-driven mindset to a material-efficiency-driven approach, where barrier, sustainability, and functionality are engineered into a unified, recyclable solution. Instead of laminating dissimilar materials, functional barrier coatings like acrylic, PVDC-alternative systems, or inorganic barrier layers, are applied directly onto BOPP or BOPE substrates to integrate barrier performance within recyclable structures."

As global brand owners accelerate their commitments to demonstrated recyclability under tightening global rules, the ability to engineer high-barrier properties on a single polyolefin substrate allows converters to turn sustainability into a distinct manufacturing advantage. Smarter surface chemistry ultimately ensures that plastics can coexist as high-performance materials while supporting the circular economy.