Black packaging has long been a thorn in the side of recyclers. While carbon black, the colourant most commonly used, is both economical and has good visual opacity properties, it poses huge problems at sorting facilities.
The pigment interferes with the reflectance by absorbing the near-infrared (NIR) light, making it impossible to identify the polymer. Even traces of carbon black can hinder the sorting of polymer scrap, which means the waste will not be able to be recycled but instead ends up being incinerated or landfilled.
With the development of near-infrared detectable black pigments, various companies have sought to address this issue.
The latest to join the offerings available on the market is the NIR-reflective Sicopal Black K 0098 FK developed by BASF’s Color & Effects brand.
A Colors & Effects research project led by Christof Kujat, head of Global Technical Industry Management for Plastics set out to proactively tackle the industry need for recyclable black plastics that can pass through infrared sorting at materials recycling facilities.
“Building on our established Sicopal Black technology…our team has succeeded in creating a new pigment for recycling of black plastics with improved value in use,” said Kujat.
The new black pigment offers high colour strength, opacity and food contact compliance. It is suitable for all commonly used plastics materials, including high heat polymers. Due to its processing stability, multiple processing steps and closed-loop recycling pose no problem.