Walk through any supermarket and you will see it: brands moving from plastic pouches and laminated cartons to paper. Pressure from customers, recyclers and plastic waste rules is pushing packaging towards paper – but paper on its own soaks up grease and water. Barrier coatings are what make the switch possible.
What a barrier coating does
A barrier coating is a thin layer applied to paper or board that blocks something from passing through:
- Water and moisture – for cartons, cups and wraps.
- Grease and oil – for food service and snack packaging.
- Oxygen and aroma – for longer shelf life.
Traditionally this job was done by a polyethylene (PE) film laminated onto board. That layer makes recycling difficult.
The new approach: water-based dispersion coatings
Instead of a plastic film, mills apply a water-based coating using equipment similar to normal board coating. These coatings are typically based on acrylic, styrene-acrylic or bio-based polymers, sometimes with mineral pigments.
Why it matters: the finished board can often be repulped and recycled like ordinary paper, which brand owners increasingly ask for.
What goes into these coatings
- Binders/polymers – form the barrier film. Acrylic binders such as Pidicryl 128 M are part of this family.
- Minerals – plate-like coating clay creates a “maze” that slows water vapour and grease.
- Dispersants and additives – such as Pidicryl 6300J to keep the coating smooth and stable.
- Starch or surface sizing – to close the base sheet before coating, using surface size chemicals.
Benefits
- Packaging that is easier to recycle.
- Meets brand and retailer sustainability targets.
- Opens new markets for board mills – food service, quick commerce, e-commerce.
- Often runs on existing coating equipment.
Challenges to plan for
- Base board quality matters more – a closed, smooth surface needs less coating.
- Coat weight control – too thin leaves pinholes; too thick adds cost.
- Blocking – coated reels can stick together if not dried properly.
- Testing – Cobb, grease (KIT) and water vapour tests become routine.
Where it is used
- Paper cups and food trays.
- Quick-service restaurant wraps and bags.
- Packaging board for frozen and chilled foods.
- Duplex board for FMCG cartons needing moisture resistance.
What it means for Indian mills
Mills that can offer a recyclable, barrier-coated board will be talking to a growing list of buyers. The first step is usually a trial: base sheet, a coating formula and a set of test targets agreed with the customer.
Exploring barrier board? Tell us your base grade and target properties – we will suggest coating materials to start your trials. Talk to us →