Revolution ahead for plastic food packaging?

United Kingdom – Automated sorting systems designed to boost the recycled content of plastic food packaging will probably be available within a few years, predicts UK resource recovery specialist Axion Consulting. This view is based on technical research undertaken for the Waste & Resources Action Programme.

Major breakthroughs in sorting technologies could increase the recycling of the estimated 180 000 tonnes of waste polypropylene (PP) pots, tubs and trays arising each year in the UK, Axion claims. Over 60% of this total comprises food-contact packaging, with the remaining 40% being non-food applications such as cleaning products and cosmetics.

Axion’s research set out to develop an automatic process using diffraction gratings to identify and separate the PP that has been in contact with food from that which has not. This is important because European food packaging regulations state that only PP that has been in prior contact with food can be recycled into new food-grade PP.

A specific pattern

The process explored by Axion involves marking food-contact PP packaging material with lines (a diffraction grating) that can be scanned by a laser to reflect a specific pattern. This pattern is then captured by a camera connected to a computerised image recognition system which can identify the marked food-contact PP packaging.

The project represents an ‘innovative application of existing technology’ that could ‘revolutionise’ any food-contact plastic recycling in offering a commercially-viable automated solution, says Richard McKinlay, chemical engineer at Axion. ‘Manual sorting is simply too expensive.’

McKinlay estimates the total capital cost for a single diffraction grating sorting unit, including conveyors and ancillary equipment, at £500 000 (Euro 593 000) with a potential payback within four years.

For more information, visit: www.wrap.org.uk and www.axionconsulting.co.uk

Source: European Plastics News