News for the plastics and rubber industry. Macplas
Materials Monday, 13 June 2022

NIR-detectable masterbatch for black flexible applications

The global masterbatch leader Ampacet has added Rec-NIR-Black PE 512 for black flexible applications to its carbon-free Rec-NIR-Black masterbatch range. Rec-NIR-Black masterbatches are near-infrared (NIR) transparent to allow sorting with near-infrared optical sensors. The reuse and recycling of black packaging waste supports circular economy initiatives.


Rec-NIR-Black PE 512 is NIR-detectable, while providing a high level of opacity for black flexible packaging. Products made with this NIR-transparent masterbatch solution are oriented to the polyethylene flow when using a sorting model suitable for dark plastics. Rec-NIR-Black PE 512 is suitable exclusively for indoor use because, unlike conventional carbon black masterbatches, it does not provide a stabilizing effect against UV degradation.


To recycle plastic packaging into useable resins, plastic waste is presorted by resin type at plastic recovery facilities. Presorting, an essential and challenging step, especially with the various characteristics of each resin type, results in a pure stream of resin. In most recovery facilities, automated sorting technologies use near-infrared optical sorters.


Near-infrared optical sorting, however, cannot identify and separate plastics that contain carbon black, the most-commonly used black pigment. Carbon black absorbs a significant part of the ultraviolet and infrared spectrum, preventing the reflection of infrared light back to the sensor and consequently blocking the recognition of the resin’s fingerprint by a NIR scan.


While most black packaging cannot be sorted by recycling companies and can only be used for energy recovery, packaging using Ampacet’s NIR-detectable black masterbatch products can be scanned by near-infrared technology for automated sorting at recovery facilities.