Classic carbon black pigments cause black plastics to be invisible in the near-infrared sorting process. These pigments absorb NIR radiation almost completely, leaving no evaluable signal. However, pure iron oxide is not a suitable alternative in many applications because its magnetic properties can interfere with sensitive metal detectors used in the food industry, triggering false alarms. Soluble dyes are often economically unattractive, and nigrosine is ruled out for regulatory reasons.

ROWASOL NIR-DEEP BLACK offers the perfect solution: It is a deep black color that is brilliant in visible light yet NIR-detectable with a strong reflective signal for reliable sorting. It is also compliant with food contact regulations, non-magnetic, and suitable for use in polar thermoplastics (e.g., PS, PET, ABS, PC, and PMMA). The slightly less deep black version, NIR- BLACK, is also available for PE and PP.

Both variants offer a "cooling effect" by reflecting heating infrared (IR) radiation, so components heat up less. This improves thermal management, depending on the application. For example, it can be used in packaging, façade elements, or automotive interiors. Even at a dosage of just 1%, these highly pigmented liquid inks achieve excellent opacity and cover colored recyclates homogeneously.

With this new development, ROWASOL is making a significant contribution to the circular economy and more sustainable production.