Seaweed-based barriers are getting a lot of attention as alternatives to synthetic coatings and PFAS. What are seaweed polymers so good for high-performance food packaging?
Seaweed-based coatings offer a unique combination of performance and environmental benefit. At Notpla, we've harnessed seaweed in a completely natural wait to create a coating to provide effective grease-proof barriers while being completely biodegradable in home composting conditions within weeks, not requiring the high temperatures of industrial facilities. Unlike synthetic coatings or PFAS, seaweed breaks down naturally without leaving microplastics or toxic residues behind.
What makes seaweed particularly compelling is the feedstock itself. It grows abundantly without requiring fresh water, fertiliser, pesticides, or arable land. It doesn't compete with food crops, and can be harvested sustainably at scale. From a performance perspective, seaweed-derived coatings can match the barrier properties of plastic laminates in real-world food service applications, where packaging might only be in use for 30 minutes before disposal. We don't need materials engineered to last forever when the functional need is measured in minutes. Notpla's seaweed-based options align material lifespan with actual use, which is fundamentally what sustainable packaging should do.
What have been the key challenges in taking seaweed-based coatings from concept to industrial production? How does working closely with paper mills help make this possible on existing lines?
The biggest challenge has been bridging the gap between what works in the lab and what works at industrial scale. Natural polymers like seaweed face inherent variability including seasonal harvests, regional differences, batch-to-batch inconsistencies, which are things that don't happen with synthesised plastics. We had to develop supply chain infrastructure and refine processing techniques to standardise material properties reliably enough for commercial production.
The manufacturing process itself required significant modification. Coating cartonboard with seaweed-derived materials at speed, with consistent coverage and performance, meant adapting existing coating technologies and conducting extensive trials to prove feasibility. Working closely with paper mills has been essential to this process. Rather than requiring entirely new infrastructure, we've focused on making our coatings compatible with existing coating lines. This means mills can adopt seaweed-based barriers without massive capital investment in new equipment; they can use the machinery they already have, which dramatically lowers the barrier to adoption and speeds up market penetration.
This collaboration also creates a feedback loop: mills understand the practical constraints of industrial production (line speeds, drying times, substrate compatibility) and that real-world knowledge helps us refine the material to perform reliably in their operations. It's not just about developing a great material; it's about developing a material that can actually be manufactured at scale within the existing packaging ecosystem.
With regulations evolving, how can packaging producers future-proof their barrier and coating strategies?
The regulatory landscape is shifting rapidly, and producers need to think beyond incremental improvements to plastics. The EU's Single-Use Plastics Directive is just the beginning. We're seeing governments worldwide tightening definitions of what qualifies as "plastic-free" and imposing stricter requirements on recyclability and compostability. In 2023, Notpla became the first and only material recognised by the Dutch government as meeting the EU's strictest plastic-free criteria, which shows how high the bar is being set.
To future-proof barrier strategies, producers should start by questioning the material paradigm itself: does this application need to be plastic at all? For short-use applications like food service packaging, materials that biodegrade naturally in home composting conditions will have a significant advantage as regulations evolve. Producers should also pay attention to certification standards and look for materials that meet not just recyclability criteria, but genuine end-of-life performance in real-world conditions, not just industrial facilities.
Critically, the true cost of materials needs to be part of the equation. Plastic coatings may appear cheaper today, but that price doesn't account for the societal and environmental cost of their end-of-life impact on human health and ecosystems. As Extended Producer Responsibility schemes expand and waste management costs are internalised, materials that genuinely disappear at end-of-life will become economically competitive, not just environmentally preferable.
The smartest move producers can make is to invest in materials innovation now, by working with companies developing natural polymer alternatives, testing them in their applications, and building the supply chains that will be required when regulations tighten further. The future isn't about making plastic slightly better; it's about replacing it entirely where it doesn't need to exist.
