Impact of Carbon Black pigment on the recycling process

But before diving into the recycling aspect, let’s see what is precisely the carbon black.

What is Carbon black?

Carbon black is composed of fine particles consisting mainly of carbon. Various features of carbon black are controlled in production by partially combusting oil or gases. It’s international color Index is PBK-7.  The carbon black is widely used in various applications from black coloring pigment of newspaper inks to electric conductive agent of high-technology materials.

What are the application of carbon black?

A large amount of carbon black is used mainly in tires as excellent rubber reinforcement. Carbon black is also an excellent coloring agent as black pigment, and therefore is widely used for printing inks, resin coloring, paints, and toners. Furthermore, carbon black is used in various other applications as an electric conductive agent, including antistatic films, fibers, and memory disks.

Why is carbon black an issue for the recycling process?

One important topic of recyclability is to use colours which are detectable during the recycling process and enable correct sorting. The Carbon black plays a big role in this scenario.

The recycling process have different steps: Collecting, sorting and recycling. After the household waste is collected, it needs to be prepared for recycling through optimal sorting. The sorting will be done per material like paper/ carton, metal, flexible or rigid plastics. The rigid plastics will be sorted per type, which means HDPE, PET and PP will be sorted for separate recycling streams. Which type of plastics are recycled, depends on the country.

To be able to sort correctly, the packaging needs to be detected by the so called “near infra-red” sensor, short NIR. This sensor detects the type of polymer by spotting light points on the surface of the packaging and identifies the reflected light range of the biggest part of the polymer. This is special for each polymer type, e.g. HDPE, PET, PP etc. Is it not possible to detect the packaging surface, the packaging can’t be detected and subsequently not sorted. So it will be rejected for incineration or landfill.

A big issue for the NIR are carbon black containing colours.  Carbon black is absorbing the NIR-light and the sensor doesn’t recognize a reflection. That’s why using carbon black containing colours for packaging is not beneficial for recycling, because it can’t be sorted correctly and will be rejected. Not only the colour black can contains carbon black, even dark colours can contain a share of carbon black which is already affecting the recyclability of the entire packaging.

To avoid this procedure, we currently work together with our suppliers to find alternative black colours and identify all other colours which are containing carbon black. With this “small” adaption, we decrease landfilling and incineration of high value material and enable their recycling.

New EU-tax for non-recycled plastic packaging waste

The big topic for the next year will be recycling: The EU decided to put a levy in place as of 1st January 2021 for non-recycled plastic packaging waste. The EU foresees a 0.80 €/kg levy for all member states as part of the coronavirus pand emic recovery package and all proceeds from this tax will go back to the EU. More details are not published yet, but we will keep you updated as soon as possble.

The conclusion for us is that we need to focus even more on design our packaging fit for recycling and advise our customers to do so, to avoid expensive fees.

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