A case study of life cycle assessment (LCA) for PS/PET/PLA boxes used on food packaging field.

A screening of life cycle assessment (LCA) methodology to the evaluation of the damage arising from the life cycle of Polystyrene (PS), Polyethylene Terephtalate (PET) and Polylactic acid (PLA) boxes used for food packaging application has been carried out. For every line of product the environmental impact of the expanded version and the rigid version was takes into consideration. Purpose of the experimental work was to individualize and analyze the principal tied up environmental impacts to the life cycle for packing produced commercially. The study, after the phase of damage evaluation, allowed us to advance a possible proposals of improvement, with the purpose to minimize the total damage and to guarantee a level how much great possible of the environmental sustainability of the examined products. The production of the boxes in expanded material involves the use a less percentage of row material in comparison to the rigid boxes. The production process is articulated as following: 1) Melting of virgin granules; 2) Extrusion of the melted material; 3) Production and cooling of the obtained leaf; 4) Stamping of the leaf. In the case of the expanded material, in the first phase an expanding liquid is added, generally butane. The leaf of expanded polymer needs a period of rest, that allows the expanding gas to go out of the leaf. Only in some cases, the box is laminated with a multilayer film, type PSEVOH- PE