The black that sorting systems can see

One of the problems long plaguing recyclers has been that of black plastic packaging waste. Most black plastic packaging is coloured using carbon black pigments, which creates a problem for the optical sorting systems that are commonly used in plastics recycling. Carbon black is not detectable by near-infrared (NIR) optical sorting equipment, because it does not allow the light to pass through.

As a result, black plastic packaging commonly ends up as residue waste and is disposed of in landfill or recycled into lower value materials where polymer sorting is not required.

Prompted by demand from the market Ampacet, a global producer of colours and additives, set itself the task of solving this challenge. The solution it came up with - REC-NIR-BLACK  - was recognized with the PRSE Product Technology Innovation Award at this year’s PRSE event in Amsterdam this week. 

“We listened to our recycling customers, who were struggling with the problem of black packaging and decided to meet that need,” said Philippe Hugele, strategic business manager moulding. “A lot of time went into developing the product , and then we had a long period of testing – to make sure that it worked.” The new near infrared detectable black masterbatches are suitable for use in all conventional processing technologies. “We have a formulation for polyolefins and polyester, and are working on one for polystyrene,” said Hugele. 

“One of the good things about the product is the fact that it does not affect the dimensional stability  - warpage, which can lead to leakage, does not occur in the products.”

The near infrared detectable black masterbatch is part of Ampacet’s sustainable development programme, which also includes odour scavengers, its REC-O-Black, consisting of 95% recycled feedstock: “We recycle the carbon black from tires,” said Hugele -  as well as a new PET opacifier for dairy product packaging “which makes the PET opaque, to protect the contents of the packaging”. The sustainability portfolio also includes Ampacet’s Blue Edge technology, that is added to recycled PET to counteract the yellowness that can occur.