Special Thermoformed
Special Thermoformed trays Biodegradable Article contributed by Cesare Vannini, Packaging System R&D Coopbox Europe s.p.a., Bibbiano, Italy Cross-section of foam Expanding film Coopbox S.p.A., headquartered in Reggio Emilia, Italy, is a producer of innovative packaging solutions for fresh foods. Coopbox has a very long history in the packaging industry. Founded in 1972, the company, always focused on innovation, recently became very active in the steady development of innovative and environmental friendly packaging solutions for retailers and the modern packaging industry. The idea of developing biodegradable foam packaging for fresh food started in 2003 and the first step was the selection of a material from the different biopolymers available on the market: starch, biopolyesters, polylactide, etc. Finally PLA was the chosen material, first of all for the good mechanical properties and the possibility to process the material with standard equipment. Not only has PLA a better mechanical performance than alternative traditional polymers used for rigid packaging (PET, PS, PP) but it is 100% produced from annually renewable resources such as corn. From this base a development project started with the involvement of the universities of Naples, Rome and Reggio Emilia, and the important collaboration of NatureWorks, the raw material supplier, all along the way. The basic idea was to use a foam solution because it allows a significant weight reduction of the pack. In general with traditional polymers, depending on the application, the foam tray is 30-50% lighter than rigid material. It is immediately evident that a biodegradable foam is a double environmentally friendly solution: firstly because it uses raw material from a renewable resource and secondly because of the weight reduction of up to 50% that is possible to obtain with the use of a foam instead of a rigid foil. Today Naturalbox ® is the first foamed PLA tray on the market with worldwide patent pending. Its first public presentation was at Interpack 2005, in the “Innovationparc Bioplastics in Packaging”. Naturalbox is recognised as a true innovation on the market, and has received several awards: the “Italian Oscar Dell’Imballaggio 2005”, the “UK Meat Industry Award 2006”, and the 22 bioplastics MAGAZINE [03/07] Vol. 2
Special foam trays for fresh food “Bioplastics Award 2006” for the best biodegradable food packaging. To obtain a PLA foam, extensive tooling modifications were necessary in comparison to the standard extruding technology for XPS (Extruded Polystyrene Foam). Coopbox invested two years in development, together with a new screw profile, new die and accessory equipment - everything was specifically projected to obtain the first commercially available PLA foam tray. The main characteristics of the product are: density of 300 g/l and good mechanical performance. Naturalbox trays are certified in line with the European food contact standards and comply with the European standard EN13432 for compostable packaging. Naturalbox ideally is used to pack fresh food: fresh meat, processed meat, fish and vegetables. Closing can be performed with two different packaging technologies: top sealing or stretch-wrapping. With the top sealing solution using a top film in PLA (this film has excellent sealing resistance, natural antifog properties and enhanced transparency) a 100% biodegradable pack is obtained. Naturalbox can be closed on standard top sealing machines and has a gas barrier lower than PET but definitely higher than PP. Another possibility is to use a standard stretch-wrapping machine with a standard stretch film. In this case high packaging speeds can be reached and for this application the mechanical properties are very important and the foam tray solution is very appropriate. Currently both PE and PVC film are used, as any biodegradable stretch film able to work on automatic wrapping machine is available today. Commercial introduction is entering a very crucial phase. Several trials have been, and are currently being, conducted all over Europe and, given the novelty of the product, Coopbox has encountered a lot of interest. The number of awards provided visibility, but only an entrepreneurial pioneering vision, the growth of people‘s consciousness about the environment and some legislative “effort” (as a result also of the activities of European Bioplastics) is now supporting the company‘s development. Today Naturalbox is present in Dubai (organic food), in Denmark (potatoes), in Italy (poultry, fish and cheese at the Finiper retail chain), and in France (at Bodin industries for organic poultry). Moreover, at the moment Coopbox is testing a new application for frozen fish for an important retailer in the UK and is approaching the German organic meat/poultry market developing a system with VC999 machines. Looking ahead the company foresees a 2008 full of opportunities, with growing interest from several promising prospects. www.coopbox.it bioplastics MAGAZINE [03/07] Vol. 2 23
