The food supply sector relies on packaging to provide a physical barrier between the food product and the external environment ensuring hygiene and protection from physical, chemical and biological agents, thereby enhancing the shelf life of the product. However, packaging technology has to balance food protection with increasing environmental pressures and tightening packaging regulations on municipal disposal. Food packaging waste (around 45 million tonnes per year in Europe) represents 60% of all packaging by volume produced in developed countries, and over one third of this goes to the consumer household bins and ends up in landfill.
Existing products for the application of paper and board food packaging have a number of limitations. The most common materials used are based on petrochemical derived polymers due to their favourable functionality characteristics, such as good tear strength and barrier properties. However, their dependency on oil along with increasing costs is making the food packaging sector vulnerable. There is an increasingly strong market drive for food packaging to be derived from sustainable resources, particularly for coatings. The potential to recycle or compost paper/card packaging after use is limited due to petroleum derived coatings which inhibit the processes. Other coating materials are causing health concerns. In particular, perfluorooctanoic acid (PFOA) coatings, which are extensively applied to paper food packaging to provide grease resistance, have been linked to cancer, reproductive problems and immune disorders. However these compounds are still in use by the fast food industry.
The implementation of the European Directive on Packaging and Packaging Waste (94/62/EEC), the Packaging Regulations (2003), and an increase in consumer concern for the environment are promoting the recovery, recycling and/or composting of paper packaging. Although recycling of food packaging (derived from plastics or paper/paperboard coated with plastics) is currently achievable, it is a difficult and expensive process. Food packaging materials usually consist of a large number of different types of polymer each of them containing different processing additives such as fillers, colorants and plasticisers. Paper/paperboard packaging material may be coated or multi-layer composite of different polymers for better performance. Wax-coated paper packaging materials often renders recycling uneconomic, (mainly as a consequence of requiring multiple processes and very specialist equipment) making disposal to landfill a more convenient alternative.
The main objective of the PlantPack project is to develop a sustainable, natural food packaging coating product derived from seaweed and starch, which will be applied to paper and cartons in the form of a spray coating. The coating is intended to replace the current petroleum derived coatings at a more competitive cost. The final product will also be both recyclable and compostable, thus providing an all-round disposal option. The new packaging will have the appropriate symbols to clearly show the consumer their disposal options.
There are a number of scientific, technological, societal and policy, and also economic objectives for the project including the enhancement of the current understanding of the effects of combining seaweed extracts and starch on mechanical parameters of food packaging coating for paper wraps and cardboard; to study the relationship between the relative proportions of seaweed extract and starch and brittleness, strength and barrier properties of the developed coating applied to paper and cardboard; to develop an aqueous solution spray coating of seaweed extracts and starch that will adhere to paper and cartons; to reduce the plastic waste in landfill in the coming years and to improve the recycling and composting of coated paper.
Current progress to date:
Substantial research work completed by the Consortium has resulted in a range of coatings based on starch and seaweed extracts. They have subsequently been applied to both paper and paperboard substrates supplied from within the Consortium. Preliminary evaluation studies have been performed to determine the performance of these coatings for selected end user applications.
A number of coatings will be scaled up to determine their commercial competiveness in comparison to current petroleum derived coatings and suitable disposal options (e.g. recyclability and compostibility).