COLOUR AND MASTERBATCH | MATERIALS
and sustainable masterbatch portfolio. UK masterbatch producer Colour Tone is
currently dedicated to ensuring that plastics’ long term future is sustainable. “With single-use plastics hitting the headlines recently as the major culprit for environmental harm, it is easy to forget that plastic is a sustainable material,” says Tony Gaukroger, Director, Colour Tone Masterbatch. “In fact, it is just the way that we treat plastic at ‘end of life’ that is preventing it making a positive contribution. If we were to effectively recycle single-use plastics instead, we could significantly reduce the amount that goes to landfill and produce a valuable feedstock for new, more sustainable products. This can only be achieved if we can automatically separate the mixed post-consumer, plastics waste back into original polymer types prior to recycling. So how can we sort mixed plastics waste more effectively? “The current use of near-infrared (NIR)
spectography offers a highly efficient means of sorting mixed plastics waste by polymer type. This is coupled with additional optical sorting methods, so plastics can be sorted by colour as well as by polymer types. However, the problem with this process is that if the plastic is coloured and the colourant in the packaging absorbs rather than reflects NIR the sorter is unable to identify its ‘signature’ from the spectrophotometer.” In 2011 Colour Tone was asked to support a
project sponsored by UK recycling body WRAP to help solve the problem of how to recycle single- use black plastic packaging so it can be automati- cally detected for recycling. It resulted in the development of a novel detectable colourant that enables black plastics to be made ‘visible’ to optical sorters, since it reflects rather than absorbs NIR light. It proved that this technology’s adoption would enable the detection of black plastics in the mixed waste stream. Gaukroger adds that a misconception still persists that by simply removing carbon black instead, it will optimise the detection and sorting of coloured packaging. “Carbon black is an extremely efficient absorber of infrared, but if you remove it from a colour it does not necessarily solve inherent optical detection problems,” he says. “Since all coloured pigments have their own individual characteristics or infrared ‘footprints’ with varying degrees of infrared absorption, the combination of these can inhibit the ability to NIR sort too. There-
www.injectionworld.com
fore, the blending of pigments presents a complex challenge, as different combinations may contrib- ute to differing reflectance levels in the near-infra- red range. So when you mix different pigments together their attributes can in some instances significantly decline as their signature may cancel out others reflectance levels.” Colour Tone Masterbatch adds that it invested in
a spectrophotometer to help identify NIR reflec- tance levels to achieve the very best NIR sorting wavelengths for plastics that previously would have remained undetected ending up in landfill. “Our technicians are able to clearly identify pigment mixes given a near-infrared footprint and then assess every possible colourant combi- nation to find the closest and most cost effective colour match to help satisfy producers’ sustainability
concerns,” says Gaukroger. “By adopting this technology,
producers can effectively ‘future-proof’ their
plastics in readiness for recovery and recycling in the future. Since it is our belief that one day all plastics can be recycled, why not include other common household plastics too, such as laundry baskets or even garden furniture? As this is just the beginning, what we must do is adopt a different mind-set where the inclusion of reprocessed materials in plastics components becomes the norm, by designing for ‘end-of-life’. It will help to better support our circular economy, prevent landfill and make the most of our highly sustainable plastics resource.” Americhem has increased its antimicrobial functional additive range to provide protection for more applications in an increased number of markets. The company says that acquisitions and
Left: Black and white plastic under infrared light
Below:
Plastics can be provided with an infrared reflective layer
July/August 2018 | INJECTION WORLD 31
PHOTO: COLOUR TONE
PHOTO: COLOUR TONE
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64
