Impact of Production and Conversion Processes on the Carbon Footprint of Flexible Plastic Films

摘要

The present study aimed to identify and compare the carbon footprint associated with polyolefin films (linear low-density polyethylene, high-density polyethylene and polypropylene), with the idea of developing a simple and affordable empirical method to assist the flexible packaging industry, notably small and medium-sized enterprises, in estimating the carbon footprint of different products or of new products at the early stage of development. It was found that the total global warming potential (GWP) of the studied films increased 19-67% during processing when compared with the GWP embodied in plastic resins. This indicated that film production processes greatly contribute to the carbon footprint of plastic films. The relative impact of the film-making process on the total GWP of films is largely a function of plastic type, in particular, its melting point. Printing and lamination processes also contribute significantly to the total GWP of films, with the major factor being electricity use. The constant k was derived to indicate the influences of plastic types and manufacturing processes on the total GWP of films and to help calculate the carbon footprint of polyolefin films for which the production process and weight are known. Moreover, the GWP of each studied film was normalized with respect to film thickness and area. This information would be useful for packaging manufacturers and users to calculate the carbon footprint of multilayer films. The proposed empirical model showed satisfactory results, as the difference was less than 10% when compared with the results obtained from life cycle assessment studies. Copyright (c) 2014 John Wiley & Sons, Ltd.