Clariant gives the recycling potential of black plastics a much-needed boost. At K 2019, it will launch the first range of near infrared (NIR)-detectable black pigments and dyes applicable to a wide variety of recyclable plastics. The extension adds another step in the right direction addressing the sorting challenge of high-appeal black packaging for recovery and recycling facilities.

Providing an alternative to carbon black, which prevents NIR sorting scanners from identifying individual plastic types, Clariant’s set of NIR black colorants preserves NIR identifiability of common packaging plastics such as HDPE, LDPE, PP, PET, PS, PA and PVC, as well as those used for housing and components in computers, TVs and other consumer electrical and electronic (E&E) equipment. The creation of recycling streams for black plastics becomes more viable.

As a result, brand owners and packaging producers can still opt for the timeless, luxury associations consumers have with black and have greater freedom in their material choice when pursuing sustainable packaging commitments. A welcome advance for the increasing number of personal care, home care and food industry brands adopting ambitious targets for their use of recyclable and recycled plastics.

New product range allows Near Infrared (NIR) sorting of black plastics

For packaging, Clariant’s range of NIR black colorants includes new polymer soluble dye Solvaperm® Black PCR for the black / gray coloration of polyester (PET), polystyrene (PS) and polycarbonate (PC). It brings excellent color fastness to a variety of packaging including bottles for beverages, shampoos, detergents, hair gels, food and meat trays and containers for dairy products. It is food contact approved in selected countries.

New Graphtol® Black CLN pigment is especially for polyolefins – polyethylene (PE) and polypropylene (PP) – and has high fastness properties and excellent dispersion for easy and consistent coloration. It is food contact approved in selected countries worldwide.

Polymer soluble dye Polysynthren® Black H achieves high fastness black / gray coloration for packaging and E&E applications made of PC, polymethylmethacrylat (PMMA), acrylonitrile butadiene styrene (ABS), polybutylenterephthalat (PBT), expanded polystyrene (ePS) and PS, as well as PET. Of particular significance, Polysynthren Black H is one of very few colorants suitable for polyamides (PA), the largest family of engineering plastics.

Marc Zwart, Technical Manager Plastics at BU Pigments (STAR CENTER Shanghai) at Clariant said: “Optimizing plastics for recycling is crucial if we are to stop them from ending up in landfill or the environment. By offering black colorants that do not hinder the sorting process, but instead make the chosen plastic type easily identifiable, we contribute towards broader and more economical sorting and recycling of black plastic products and the prospect of greater take-up by recovery facilities. Brand owners and packaging producers selecting black would have products that are identifiable for recycling, helping to close the loop for plastics.”

Sorting accuracy verified with NIR spectroscopy to identify plastics colored with Clariant’s new product range

The sorting accuracy of Clariant’s black color palette was verified with a handheld analyzer device with a technology comparable to the NIR automatic sorting systems used in recovery facilities. The analyzer for plastic/polymer identification is a NIR spectroscopy tool that rapidly screens and identifies a variety of polymers, plastics and fiber types on-site to streamline inspection without compromising accuracy and quality.