Packaging manufacturers have carried out successful large-scale trials of an innovation that helps black packaging to be detected by Near Infrared (NIR) technology in sorting facilities.
The trials, which were carried out at the end of last year at Jayplas Plastics, found more than 99% of black trays with a special dye added were identified by NIR detectors, and sorted correctly.
Several food tray manufacturers were involved in the development of the innovation including Sharpak, Faerch Plast and LINPAC Packaging.
LINPAC manufactured the food trays for the large-scale trials, which were made with polypropylene (PP), amorphous polyethylene terephthalate (APET) and crystalline polyethylene (CEPT) - with the addition of detectable black colourants.
The dye allows NIR technology to sort black plastic waste into polymer type, so that they can be recycled. Specialist plastics consultants Nextek led the innovation of the solution of adding dye to the black packaging.
This solves the problem of black food trays, which are popular with food retailers for ’prestige’ product lines, but cannot be sorted easily from a mixed plastics waste stream. This resulted in much of it going to incineration or landfill.
WRAP and UK supermarkets including M&S and Sainsbury’s have also been involved in the multi-stakeholder effort. WRAP estimates that there are around 30,000-60,000 tonnes per year of black plastic packaging in the UK household waste stream.
A spokesman from LINPAC told MRW the company was aiming to roll out the new technology throughout its black pots tubs and trays in the spring.
Alan Davey, director of innovation at LINPAC Packaging, said: “The new colourants mean that black packaging, such as meat trays, can now be automatically detected and recovered so that they can be used in new applications as substitutes for virgin plastics.”
According to WRAP analysis, using the detectable black colourants will make manufacturing the black trays more expensive than using the traditional carbon black pigment, by 0.075p to 0.35p per tray.
However, Davey highlighted the improved recycling revenues and lower carbon emissions.
WRAP also found that approximately 0.6 tonnes of CO2 can be saved for every tonne of mixed plastics recycled.