Report Photo: ecoplus
Report Photo: ecoplus Methods of Material - Characterisation for PLA The properties of PLA depend on its molecular structure. One of the task groups has developed methods which enable an accurate and reliable characterisation of this structure, guided by DKI-Darmstadt. Processing of PLA Learning to use a new type of plastic primarily means learning to process it. This task group conducted extensive tests on the processing of PLA, using different procedures and various different products. In this process a number of surprising discoveries were made! What was particularly fascinating about this task was the gradual gain in knowledge about the properties of the biopolymer, not least because its producers, the bacteria, do not disclose all of their secrets of chirality. A generally noticeable feature were the substantial differences between the various commercial types, which were seen above all in different molar mass distributions and represented significant differences in the applicability of the products. Extreme examples, in which PLA could be processed at 300°C without showing any noteworthy degradation reactions, are countered by cases in which discolouration became visible even under normal conditions. Testing Products Made of PLA Packaging products made of PLA have to meet the same requirements as packaging made from conventional plastics. Generally PLA can be processed without problems. However, processing, like additives, can have a significant influence on whether a future packaging development will meet the desired requirements. For example all processors have to find out whether drying of the raw material is necessary or not. Runners or gates for example cannot simply be re-used. The presence of expiry dates on PLA granulates and products will take some getting used to for plastics processors. But that’s how ‘bio’ works! PLA in Contact with Food One of the CORNET project’s topics was the use of PLA packaging in the food industry. A work group within the project examined whether PLA meets all of the requirements regarding contact with food, guided by OFI Vienna. PLA packaging appears to be particularly suitable for high-price and niche segments, such as organic products with a limited shelf life or fermented dairy products. Future research projects could analyse the influence of special additives and the combination with other biodegradable materials in greater detail. (Photo: Naku) a.komenda@ecoplus.at The Life Cycle of PLA When products made from PLA reach the end of their useful life various questions arise: How is the material disposed of? Can it be composted? Does PLA have an advantage over conventional plastics throughout its entire life cycle? This part of the project was guided by CELABOR of Belgium. To summarise in frank terms: There is the green advantage, but it’s not as big as it seems. Biopolymers will guide us to a green future, but it will be only one part of a general and massive change. The most important part is the human being himself and his wealth. MT The complete report can be downloaded from www.bio-packing.at 42 bioplastics MAGAZINE [06/11] Vol. 6
