The Waste & Resources Action Programme (WRAP, Banbury / UK; www.wrap.org.uk) is investigating the potential for recycling food-grade polypropylene packaging to reduce dependence on virgin PP and divert waste from landfill. The project being pursued in cooperation with Greenstar WES Group (Redcar / UK; www.thewesgroup.co.uk) and Axion Consulting (Bramhall, Stockport / UK; www.axionconsulting.co.uk) aims to develop a food-grade process for PP, identify the technical requirements for successful PP recycling, develop the steps to achieve food-grade status and produce food-grade products using recyclate in place of virgin polymer.

WRAP’s Paul Davidson, head of sector specialists, said that using the existing recycling process for food-grade HDPE it has been possible to clean PP packaging for use in certain food-grade applications, although improved cleaning is needed for lower volatility contaminants. Better label and ink removal are also required; however, he said it has been demonstrated that food-grade recycled PP can be both thermoformed and injection-moulded successfully.

Although the project was technically challenging, Davidson said he believed a huge amount has been learned that will benefit the industry. In the next phase, up to spring 2011, alternative recycling technologies will be examined to see if low volatility contaminants can be removed, to increase the range of potential food-grade applications. Other targets are improving ink removal and finding a viable automated process to sort food contact waste from non-food contact products, as hand sorting is not cost effective.