TAGS: Additives for Packaging
Clariant develops new color concepts that makes it possible to explore a darker and more mysterious color space without the use of carbon black. The color concept is developed in its ColorWorks design and technology center near Milan in Italy. Development is in progress for polyester (PET), high-density polyethylene (HDPE) and polypropylene (PP) in both virgin and post-consumer recycled (PCR) forms.
Infrared Light for Sorting Different Materials
In most automatic sortation systems, infrared light is beamed onto plastic materials and, because different polymers reflect that light differently, the system can sort the different materials. Unfortunately, the carbon black pigments typically used to make black and other deeply dark colors absorb all or most of the NIR light shone at them and, as a result, the sensors cannot even “see” the black packaging, much less sort one polymer from another.
Late last year, Clariant introduced CESA® IR, a masterbatch range that makes black plastics visible to NIR radiation. This effect was confirmed by testing conducted by TOMRA Sorting Recycling, a Norwegian company in the field of instrumentation for recycling solutions.
But designers want more choices than pure black. Roberto Romanin, a ColorWorks designer at Clariant says, “
There are very definite trends in this direction. Some exclusive, high-end facial treatments, nutrient serums and oils are being packaged in these rich dark colors. However, most of them still use carbon black and so they have recyclability problems.”
Creating Dark Colors Without the Use of Carbon Black
To address this issue, the ColorWorks team undertook a project, to use CESA-IR technology to develop colors that could be dark without the use of carbon black. Three colors – a dark umber, a deep velvety green, and a regal dark blue – have been created initially. All three are really saturated so they are almost black but the colors come through, bringing to mind elegance, exclusivity, heritage and boldness.
Mirco Groeseling, regional circular economy and sustainability manager EMEA at Clariant says, “
Until now making dark and black plastics NIR detectable required that the amount of carbon black must be carefully controlled, and this is not always possible under real-world conditions. So, we have been seeking – and we have found --new solutions that are very black, and we have been able to remove carbon black totally from these new detectable formulations.”
The range is suitable for all major packaging polymers, including PET, polyethylene and polypropylene in various packaging applications, including trays, bottles and caps.
Source: Clariant