Gas Barrier Properties of Food Packaging Plastic Films

Gas Barrier Properties of Food Packaging Plastic Films 

Transport of gases and vapours in polymers is an important subject both from the technological and scientific point of view. Applications include protective coatings. 

Active packaging has been used for years in Japan, and in recent years active packaging has been used in more limited areas in Europe and the US. Europe does not have many commercial products on the market due to legislation restrictions. However, in 2003, the Commission of the European Community accepted amendments to a framework directive for food contact materials that will allow the use of active and intelligent packaging concepts. It is expected that they will become law in 2005 and 2006. 

Market studies predict significant growth once the legislation changes. Growth is likely to occur first in proven applications such as oxygen scavengers and later in more 

Photoacoustic spectroscopy and related photothermal products [7] are well-established spectroscopic techniques. The photoacoustic technique, apart from providing direct optical absorption spectra, can also be used to perform depth profile analysis, and characterisation of thermal properties. In addition, there has been a substantial development of new versatile and competitive instrumentation and experimental methodologies suitable for use in daily practice [6,7]. Further details on the photothermal wave phenomenon and its applications can be found in the books by Rosencwaig [6] and Almond [7] and in some of many published reviews on the subject [8-10]. 

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The gas barrier properties of ethylene-vinyl alcohol copolymers are examined as a function of ethylene and vinyl alcohol content, and their use in combination with other plastics in films, bottles and other containers for food packaging is discussed. Results are presented of a study of the crystal structure of three copolymers having different compositions. 11 refs. 

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