Films|Flexibles|Bags
Films|Flexibles|Bags Biopolymer Coatings for Sustainable Packaging By Klaus Noller Head of Material Development Department Fraunhofer-Institut für Verfahrenstechnik und Verpackung IVV Freising, Germany Whey powder (picture: ttz Bremerhaven) The Fraunhofer Institute for Process Engineering and Packaging IVV, Freising, Germany, has developed a packaging film having a barrier layer made of whey protein. This novel packaging film was developed as part of the EU funded „Wheylayer“ project. Large quantities of whey arise during cheese manufacture and whey also contains antimicrobial substances which prolong the shelf-life of foods. The work of the Fraunhofer IVV involved optimizing the barrier properties to oxygen and water vapor and also the antimicrobial effect of the coating. In order to do this, very pure protein isolates were recovered from the whey. The film-forming properties of proteins from sweet and sour whey were optimized by chemical modification. The result was innovative protein formulations having a high barrier effect and excellent adhesion and resistance to mechanical stress. This means there is no longer a need to use synthetic barrier polymers to coat conventional packaging materials - these can be replaced by the new biopolymer made of whey protein. This reduces CO 2 emissions and lowers the usage of material resources for production. The ability to subsequently dissolve the whey layer means that properly sorted recycling of the plastic film is possible. The multilayer film was manufactured using a patented roll-to-roll method. This processing method is a key precondition for fulfilling commercial criteria. The products and processes that have thus far been developed on a laboratory and pilot plant scale will be transferred to an industrial scale this year before the end of the project, meaning that the new whey layer material will soon be able to be used in the packaging sector. The Fraunhofer IVV is also developing coatings from renewable raw materials for paper which can be used, for example, for beverage packaging. The BioPaperCoating project, funded by the Federation of Industrial Research Associations (AiF), is developing biocoatings for paper and processes for their manufacture. The aim is to produce biocoatings on paper, paperboard, and cardboard for use as packaging for solid and liquid foods. These new packaging materials will replace the currently used plastics based on fossil raw materials, and especially polyethylene, in laminated packaging systems. The systems are based on compatible blends of polylactic acids and polyhydroxyalkanoates which combine the benefits of the individual components. At the Fraunhofer IVV the formulations are being tested for coating at near-industrial coating rates and are being optimized in collaboration with Fraunhofer UMSICHT. Other functionalities such as an extra co-extruded layer are also being added to the material system. 26 bioplastics MAGAZINE [06/11] Vol. 6
Films|Flexibles|Bags The FlexPakRenew project, which is being funded under the 7 th Framework Programme of the EU, is developing novel flexible papers with multilayer structures (50 to 90 g/m²) made entirely of renewable raw materials for food and non-food applications. The multilayer structures in combination with the latest developments in nanotechnology and surface coating allow barrier properties to be achieved that are equivalent to traditional plastic laminates and composites having medium and high barriers. Low permeability to water vapour and oxygen and to fats and flavours is the goal. The environmentally friendly manufacturing process and optimized recyclability or biodegradability of the material means that the emission of greenhouse gases is reduced. The Fraunhofer IVV is undertaking advanced development of the process of vacuum coating with SiOx and Al 2 O 3 in order to optimize the water vapour and oxygen barriers of the coated papers. www.ivv.fraunhofer.de OTR at 23°C and 50% RH (cm 3 / m 2 d bar) 10000 1000 100 10 1 0,1 PE-HD PP BOPP COC PE-LD PVC-P PS PC 0,01 | | | | | | 0,01 0,1 1 10 100 1000 PLA PVC-U PET PA 6 PAN PEN Wheylayer PVDC EVOH, 44% EVOH, 38% EVOH, 32% (LCP) EVOH, 27% WVTR at 23°C; 85% RH (g/m 2 d) Oxygan and Water Vapour Transmission rate Cellulose bioplastics MAGAZINE [06/11] Vol. 6 27
