British-based scientists behind a new technique that adds luminescent markers to plastic packaging labels say it will lead to marked improvements in recycling rates, if applied across the industry. Jim Drury reports.
Most of us dutifully separate our plastic packaging from the rest of our rubbish. But less than 30 percent of the UK's plastic ends up being recycled. SOUNDBITE (English) EDWARD KOSIOR, MANAGING DIRECTOR OF NEXTEK, SAYING: "Current recycling technologies look at the NIR (near infrared) signature of plastics and so we can sort plastics by polymer type. But one of the limitations is that we can't identify what the products have been used for in the past. So we can't tell the difference between a bleach bottle and a milk bottle." Researchers at Brunel University London and industry partners Nextek say their new fluorescent light technique can change this. SOUNDBITE (English) EDWARD KOSIOR, MANAGING DIRECTOR OF NEXTEK, SAYING: "This technology that we've been working on will be able to tell us whether something was previously food grade, so we can then recycle it back into food grade applications. And the big implication here is that we can close the circle on packaging for the first time." The system works by adding phosphors, the luminescent materials that give strip lights their glow, to plastic labels or packaging. SOUNDBITE (English) DR GEORGE FERN, BRUNEL UNIVERSITY, SAYING: "When the plastic bottles are sent to the recycling plant, if they have our labels on, then they'll go up the conveyor belt in the normal way. There's a system for reading the bottles currently with our labels on - that system can be changed quite easily to then recognise a bottle we want to sort, either positive or negative. And then the conveyor belt system puts a jet of air that separates the bottle into another bin." The system can be retrofitted to existing high-speed sorting systems. So it's cheap - and should make plastic recycling more financially attractive to businesses. SOUNDBITE (English) PROFESSOR JACK SILVER, THEME LEADER FOR MATERIALS CHARACTERISATION AND PROCESSING, SAYING: "It doesn't have to be confined to plastics. It could be any kind of recycling that might be interesting - in the automotive industry, in the electronics industry, in fact in the building industry." In initial full-scale tests the system sorted up to 98 percent of labelled plastics with 100 percent accuracy.