No plastics should be left behind in the recycling process. Yet, black plastic packaging used for items such as coffee cup lids, pots and food trays often end up as residue in landfill or are incinerated. Why? Sorting systems used in the plastics recycling process do not easily detect the colour black.
Up to 6 to 10 million tons of polymers are coloured with carbon black for the packaging industry. Polymers are generally sorted by detectors with Near-Infrared (NIR) technology. Proper sorting is possible if the energy received by the plastic can be reflected.
Clariant has now developed a black colourant for plastics which can be detected by the NIR. The development of this black pigment does not interfere with infrared detection during the sorting stage of plastics recycling. As a result, there is no need for black plastics to remain unrecycled.
Associated SDGs
