Automatic sorting of waste packaging

Wolfson Electrostatics News

Efforts on plastics recycling gather momentum

Work at Wolfson Electrostatics, looking at practical means of identifying materials particularly plastics for recycling, is generating increased interest as international legislation and directives come into play. Currently, electrostatic and optical techniques are being considered for a range of recycling applications. Most recently the PolyAna system, which uses infrared spectroscopy, was incorporated successfully on a computer monitor recycling line at Wayland Prison in East Anglia.

Electrostatic polymer recognition
A project sponsored by the Onyx Environmental Trust has resulted in the development of a pilot scale separator for waste plastic packaging. The separator, which incorporates a 5 metre long conveyor, has been built in the Wolfson Electrostatics Laboratories in the University of Southampton and has undergone successful trials. The separator unit sorts plastic packaging items according to their polymer group by using 'triboelectric probes'. These probes, which make frictional contact with the packaging materials, measure the electrical properties of the plastic. Once the polymer has been identified the items are automatically ejected from the conveyor line at different points into separate collection bins for recycling.

Continuing on the subject of plastics identification, Wolfson Electrostatics have recently received a grant from the Shanks First Fund to develop further technology to assist in the important function of material identification prior to recycling. Identifying materials, particularly plastics, prior to recycling is currently considered the weak link in the recycling chain. The work financed by the funding from Shanks First is enabling Wolfson Electrostatics to develop and refine practical plastic identification methods and two prototype bench mounted identification systems have been built. The Ford Motor Company is providing the industrial perspective although it is recognised that automotive recycling is only one of many areas, which will benefit from this technology.

For further information on Plastics Recycling contact Wolfson Electrostatics.