Innovative packaging using bioplastics
The BIOPACK project, funded under the EU's Fifth Framework Programme, explored the possibility of using bioplastics to better package cheese. Traditional plastics are made from non-renewable petroleum, while bioplastics are derived primarily from plant products. Hence, bioplastics are totally biodegradable and more environmentally friendly. The Danish scientists experimented with polylactide (PLA), a lightweight, flexible bioplastic produced from lactic acid. The challenge was to determine the best method for applying plasma coatings to PLA films in order to improve durability and other attributes. The first method involved siloxanes, compounds containing silicon and oxygen in varying amounts. The necessity for high oxygen content siloxanes led to the unwanted result of oxidation of the PLA film. Alternatives using lower input power allowed undesirable organic components of the siloxanes to pass through to the film. The outcome is that this method is not yet mature enough, though ideas for further manipulation of the process were proposed. Greater success was achieved with plasma consisting of hexamethyldisloxane (HMDSO) and molecular oxygen. High-tech surface analysis techniques, such as X-ray Photoelectron Spectroscopy (XPS), were used to inspect the surface of the resulting PLA film. XPS showed that the surficial carbon could be reduced remarkably, from 60% in untreated PLA to 11% using the HMDSO plasma. Unfortunately, oxygen and water vapour permeability values exceeded allowable levels. The Danish Polymer Centre and its partners from BIOPACK believe the solution lies in overcoming the film's surface roughness anomalies. They are currently pursuing additional research funding to reach the goal of an economically and technically viable biopackaging solution.
