vor 8 Jahren

03 | 2008

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  • Trays

Processing Inauen

Processing Inauen Maschinen AG from Herisau in Switzerland, well-known for the VC999 packaging machines, has been investigating this problem for some years, seeking a breakthrough that would make PLA trays and film suitable for meat packaging. Working together with manufacturers of trays and film they sought a suitable solution - principally a way to provide the thin PLA film cover with an ecologically-friendly barrier. In an extensive series of tests gas permeation levels were measured under the widest variety of conditions, and compared with PP packaging. Sealing and shelf-life tests were carried out together with the partners in the project. The VC999 tray sealing machines were appropriately modified and adapted. The company Maag-Folienveredelung became partner in the project to produce a suitable laminated barrierfilm using a SiOx barrier material supplied by Alcan-Packaging, another partner of the project. This barrier, better known as CERAMIS is implicated in-between the two layers of PLAfilms, and then laminated by an ecologically acceptable adhesive. At VC999 the performance of the trays and the film was tested under normal operating conditions and - even with contaminated edges - the process was finally brought to the standard demanded by the food industry. This fully-developed packaging concept for fresh meat under modified atmosphere (MAP) is a combination of a transparent PLA-tray, the multilayer barrier-liddingfilm, biodegradable absorbing-pads, and biodegradable labels and printing, and – not to forget - the particular VC999 tray sealing machine. Fitted with the vacuum and protective gas distributingmodule, the PLA-packaging concept obtains the same shelf-life of packed products as in PP trays with traditionally used PE/EVOH/PP barrier film. Even the absorber pads to collect liquids, when fresh meat is packed, meet the requirements of biodegradability and renewable materials; they are made from pure cellulose. Minced meat and all kinds of other fresh products can now be packed and distributed by same logistic systems to be sold in same refrigerated shelves as these products were sold before in supermarkets. This all in a protective atmosphere with a shelf life of 6+2 days for minced meat. For many other meat products the shelf life in this PLA-package is even longer – up to 12+2 days. This meets the standards required by food-packers and supermarkets for convenience foods and meat products. The known advantages of PLA, coming from renewable sources and its biodegradability are topped by a very important advantage regarding food-packaging: The possibility of inter-reaction between the product and the packaging material (known as global migration from the packaging material and its effect on the contents) is totally excluded when PLA is used. Ecological aspects Packaged organic foodstuffs should, in the interests of meeting consumer expectations with regard to natural organic products, always exclude any possible interreaction between the foodstuff and the packaging. The SiOx barrier, eco-friendly adhesives and mineral printing inks all combine to prevent such migration to the inside of the package. All components meet the regulations in force and the requirements covering ecologicallyfriendly manufacturing as well as compostable packaging (according to EN 13432). Nevertheless biodegradability is not the prime consideration. The decisive factor in eco-friendly packaging is the fact that, unlike classic plastic materials, the raw materials are obtained from renewable resources, and that with their favourable eco-balance help to minimise CO 2 emission into the atmosphere. Only by close collaboration, continuous technical exchange, and extensive testing, was it possible to offer a complete solution to users of bio-packaging, enabling them to present high quality products in particularly high quality packaging. PLA trays combine minimum harmful impact on the product with maximum product protection and shelf life. VC999 at Interpack, Hall 13, Booth A15/B16 bioplastics MAGAZINE [03/08] Vol. 3 29

Materials Article contributed by Marcel Dartee, Market Development Leader Bio Materials, PolyOne, Assesse, Belgium The bioplastics industry is highly dynamic. The more established biopolymers such as polylactic acid, thermoplastic starch blends and the polyhydroxyalkonoate family (which is still in its early days), have received significant interest. Although they are bio-based, much attention is focused on the compostability and biodegradation of these biopolymers. More recently, significant progress has been reported in the development of biopolymers which are identical or very similar to existing petro-chemical based polymers but derived from renewable resources, e.g. polyethylene from bio-ethanol and polyamides and thermoplastics polyurethanes from castor oil. Much has been said about the new and innovative nature of biopolymers and about their unique properties and characteristics, both positive and negative. Much less has been reported about what has been and can be done to improve the usability of biopolymers; the hidden secrets of colour and additive concentrates. One might think it is only the active ingredients and colorants that count and not the form in which they are provided. However, many of the ‘neat’ additives and colorants come in the form of a powder or liquid with a wide range of viscosities, making them difficult to handle for most converters. One colour and additive concentrate can combine the functionality of different active ingredients and/or colorants, from different suppliers if necessary, into a single pelletized form. The expertise and added value is not only in making active ingredients available in an easy-to-use form for converters, but also in achieving target property and process improvements by selecting the right ingredients with regard to their mutual and combined interactions, and then, effectively incorporating and dispersing the ingredients in to an additive solution. In addition, sourcing additives in a concentrate form enables a range of solutions to be sourced from one company. In the case of biopolymers there is an additional challenge. The colorants, additives and carrier resins used, may need to be in compliance 30 bioplastics MAGAZINE [03/08] Vol. 3

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