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Materials

Films with excellent barrier properties by: Elodie Bugnicourt Innovació i Recerca Industrial i Sostenible (IRIS) Castelldefels, Spain Markus Schmid Fraunhofer-Institute for Process Engineering and Packaging IVV Freising, Germany

Oxygen transmission rate °C/50% RH Q100 (cm3 (STP) m-2d-1bar-1)

Permeability values of typical plastics, bioplastics and wheylayer

10000

Cellulose-acetobutyrate

PE-LD

1000 100

PE-HD PP (oriented) PA 12

PC PUR-elastomer

PA 11

10

0,01 0,01

PS (oriented)

Wheylayer

1 0,1

Wax/paper

PVC-U PA 12 PA 66 PET (oriented) PA 6 PVC-U (oriented)

EVA-copolymer, VAC 20% Celluloseacetate

PVDC

EVOH 44%

EVOH 32%

EVOH 38%

0,1

EVOH 27%

1

10

100

1000

Water vapour transmission rate 23°C/85 0% RH Q100 (gm-2d-1)

Fig 1: Barrier properties of whey-based layer vs. other plastics commonly used in the packaging industry normalised to 100 µm thickness [2] The authors wish to acknowledge the funding from the European Community‘s Seventh Framework Programme [FP7/2007-2013] for the research leading to these results under grant agreements n°218340-2 and 315743 through the WHEYLAYER and WHEYLAYER2 projects respectively.

Fig. 2: Examples of applications for the Wheyalyer coated laminates: blisters and tubes (the packaging being currently tested)

A

s published in issue 04/2011 of bioplastics MAGAZINE [1], more and more waste from food production plants is used as feedstocks for bioplastics, following a Maxi-use© strategy. Research is ongoing to improve the performance of such bio-sourced polymers, making them competitive with their synthetic counterparts and extending the range of applications that they can fulfill. In such a context the development of a biopolymer coating for multilayer plastic films, based on whey protein (which is able to replace current synthetic oxygen barrier layers used in food packaging such as ethylene vinyl alcohol copolymers or - EVOH) is expected to be far reaching in the market. Whey is a by-product of cheese manufacturing, therefore it does not enter into direct competition with other foods. Indeed, it is estimated that converting only 40% of the currently wasted excess (of 20 million tonnes annually in Europe) would cater for the global need to replace EVOH currently used in food packaging. The whey protein-based coatings developed in the Wheylayer project exhibited excellent barrier properties, outperforming most existing biopolymers (fig. 1). Since the publication of the aforementioned article, the study has continued with subsequent steps, including presenting the project’s findings to the industry and demonstrating the scale-up ability of the production as a preliminary requirement for its commercialization. Coated films were validated for storing various food products and the shelf life of the foods packaged with conventional films was compared with the whey protein film. In addition, the coated films and derived laminates have recently been converted in different formats of final packaging, either laminated tubes or thermoformed blisters (fig. 2). The developed wheycoating, which can be removed via enzymatic cleaning, allows multilayer films to become recyclable, and so represents a significant step in terms of cascade use before a final incineration or disposal. This, along with saving in emissions and energy, leads to a significant reduction in the environmental impact of packaging as shown by the life cycle assessment that was carried out. All in all, this new economical use of a bio-sourced by-product from the industry safeguards the performance of packaging and improves the use of resources throughout its life cycle, leading to tremendous advantages for this type of packaging compared with traditional plastics. www.wheylayer.eu

References: [1] E. Bugnicourt, O. Mc Nerney, A. Lazzeri, “Maxi-use of wastes from agro-food processing to obtain truly sustainable bioplastics”, Bioplastics magazine, 04/11, Vol 6, p 32-34. [2] E. Bugnicourt, M. Schmid, O. Mc. Nerney, J. Wildner, L. Smykala, A. Lazzeri, P. Cinelli, “Processing and Validation of Whey-Protein-Coated Films and Laminates at Semi-Industrial Scale as Novel Recyclable Food Packaging Materials with Excellent Barrier Properties”, Advances in Materials Science and Engineering, vol. 2013, Article ID 496207, 10 pages, 2013

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bioplastics MAGAZINE [05/13] Vol. 8

Profile for bioplastics MAGAZINE

bioplastics MAGAZINE 05/2013  

bioplastics MAGAZINE is the only independent trade magazine worldwide dedicated to bioplastics (i.e. plastics made from renewable resources...

bioplastics MAGAZINE 05/2013  

bioplastics MAGAZINE is the only independent trade magazine worldwide dedicated to bioplastics (i.e. plastics made from renewable resources...

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