Anti-microbial packaging materials are one of the most promising active food packaging applications. However, few commercial products exist today because it is difficult to produce a safe and effective packaging material at reasonable cost.
In the future, however, anti-microbial agents could be incorporated straight into the packaging film. The Solplas project, a consortium of technical institutes and European technology firms including Philips and Ferrania, is attempting to stimulate this trend by placing anti-microbial agents directly on the surface of coated film.
This innovation could put European companies ahead in this exciting market. "The output of the project should be high-performance barrier coatings for food and display applications," says project co-ordinator Dr Sabine Paulussen of Vito, the Flemish institute for technological research in Belgium.
Existing barrier coating technologies on polymer films roughly fall into twocategories: atmospheric and vacuum-based. Atmospheric techniques consist ofapplying a lacquer followed by thermal, UV or electron-beam irradiation postcuring. Vacuum coatings can be made from aluminium or, for clear packaging,inorganic metal oxide (MeOx). More specialised coatings are usually acombination of the two.
About 50 per cent of the coated polypropylene food packaging market uses clearpolyvinylidene chloride (PVdC). This transparent and almost colourlessthermoplastic is noted for its extremely low permeability to gases, whichhelps preserve flavours and aromas rather better than the previous solution,PVC.
However, environmental concerns about PVdC have stimulated developmentsin other materials, such as multi-layer combinations of lacquers and MeOxcoatings, but these technologies are complex and costly to produce.
There has also been a strong desire to move away from low-pressure plasmatechnologies that need expensive and limited volume vacuum equipment toatmospheric pressure approaches. The Solplas aerosol-assisted atmosphericplasma (AAAP) technique could represent a major step forward for suchdeposition technology, and the consortium is preparing to submit one or two patents inthe near future.
"Apart from the financial support we've received, our focus has allowed usto pull together well-recognised centres of expertise into a Europeanproject, which has encouraged us to share ideas in a supportive environment,and therefore develop innovative technologies more rapidly than couldotherwise have been done," said Paulussen.
"There is a large potential for the European food packaging industry andproducers of mobile electronic consumer goods, important spin-offdevelopments in biosensors, printing and imaging technology, coating oftextiles and steel and aluminium plate, which will generate a lot ofbusiness for European chemical companies and surface engineeringbusinesses."
The Fraunhofer Institute für Silicatforschung research organisation in Germany will use its existing network of industrial contacts to stimulate interestin the technologies developed in the project. Dutch firm Philips and Italian firm Ferrania are keen to use the technology in plastic displays. And Belgian-based UCB SurfaceSpecialties will implement the Solplas AAAP deposition technology inits base film production lines.
The European market for plastics used in food and beveragepackaging is an industry to watch out for. A survey by US consultancy Frost &Sullivan suggests total sales will have risen from €3.92 billion in 2000 to€5.71 billion in 2007, equivalent to an annual growth rate of 5.5 per cent.
Principal growth engines for the market include the rising sales ofconvenience foods and ready meals, as well as advances in electronics andbiotechnology that will lie at the heart of this new packaging.