vor 8 Jahren

03 | 2008

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  • Biodegradable
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  • Trays

Special Thermoformed PLA

Special Thermoformed PLA articles can be punched out either in a separate step or inline (punch and drop). “However, the PLA skeleton was rather brittle in past, so we had to use a special winder for winding the skeleton,” Martin Barth says, “with the actual PLA-Qualities we can use standard winders. If processed properly PLA can easily be reground and fed back into the process.” (Photo: Nedupack) (Photo: ILIP) But even if standard equipment can be used, most converters have invested in modifying their production lines and in optimizing their processes. The ‘what’ and ‘how’, remain, however, confidential. Market development The market for rigid PLA packaging is developing quite well. However, when comparing PLA packaging with packaging products made from traditional plastics, most companies still see bioplastics as a niche market. Others, like Nedupack, report that PLA products already generate about 10% of their total sales, and are receiving an increasing number of enquiries. “This includes all kind of clamshells, tray and lid combinations and trays with inserts“, as Jhon Bollen pointed out. In addition Nedupack manufactures blisters for a broad range of non-food applications. Patrick Gerritsen, Business Unit Manager of natura packaging is enthusiastic about the development. natura packaging is a German trading company for biodegradable packaging and sells products of companies like ILIP, Nedupack and others to all major retailers and discounters. Patrick: “In the last two years we saw a really dramatic growth in the field of rigid PLA packaging”. Did they sell about 20 million units of rigid PLA packagings in 2007, Patrick expects more than 50 million for this year, based on orders booked and serious requests, as he added. In the beginning, PLA trays, punnets and clamshells replaced rather the standard products such as PET-packs for tomatoes etc. Today Patrick Gerritsen is more and more faced with cumstom made packagings for a much wider variety of filling goods. “Our clients ask for packaging for grapes, wild tomatoes, mushrooms or even fresh herbs,” he says. The packagings range from open trays with loose lids to hinged containers. And even in the field of meat and meat products Patrick is expecting a very positive development. “At least for Germany and Holland, the areas we supply most of our products to,” he adds. These PLA trays are closed with a so called sealed lid made from PLA film. This film is barrier-coated with an SiOx-layer. 26 bioplastics MAGAZINE [03/08] Vol. 3

Processing Rigid PLA Packaging for Meat Products Article contributed by Arne Reinhart Meyer, Project Leader Bioplastics, VC999 Inauen Maschinen AG, Herisau, Switzerland Since the sizes of meat counters in self-service supermarkets have been reduced to an absolute minimum the distribution of meat and poultry, fish and several types of convenient-food are sold in plastic trays under modified atmosphere to give the products a longer shelflife. New systems of distribution made packaging of fresh food, and in particular the packaging of poultry, meat and meat products, fish, and dairy products an absolute necessity. The demand for transparent food trays took off when consumers accepted packaging as necessary part of the product to keep it fresh before distribution. For the last twenty years the distribution of most fresh products sold in self-service corners in supermarkets has been common in plastic trays with sealed lidding on the top and attached labels to give the buyer necessary information. Consumers never thought about differences in plastic, necessary barriers or other particularities because they bought convenience, freshness and products safely packed under best conditions. Up to now transparent PLA trays have been no more than a niche sector in the fresh food packaging business. Now totally safe for use in meat packaging Trays sealed with a PLA film have long been seen as unsuitable to protect perishable food in modified atmosphere (MAP) during the required shelf-life (e.g. one week for minced meat, or 14 days for poultry). Adequate barriers to protect packed products from evading humidity and to keep the protecting gas-mixtures such as carbon-dioxides and oxygen in the package, barrierfilms became the common packaging material. Most of today’s multilayerbarrier-films use EVOH as a sufficient barrier. With any layer of these special-type polymers (such as EVOH) however, the advantages of biodegradability and ecological balance are lost. Although PLA trays have superior transparency to the wellknown monolayer PP trays, and although PLA forms a strong seal, they were always regarded as unsuitable for packaging under modified atmosphere - either because the packs broke under vacuum conditions, or because they could not be sealed with a thin PLA film by the normal process technique. Because of the consumer‘s perception of product image the distribution chain nevertheless remains very interested in such packaging. However all of the trials carried out so far with these trays proved unsuccessful due to their inadequate CO 2 and oxygen barrier. 28 bioplastics MAGAZINE [03/08] Vol. 3

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