Page 64 - Plastics News Issue October 2025
P. 64
TECHNOLOGY NEWS
polymers is especially revolutionary. These sys- on color or form but on the properties of the
tems are able to differentiate between PET and material.
HDPE, polypropylene, and polystyrene based
on training algorithms on massive databases of The output? Recycled plastics with high purity
polymer images and spectral data within milli- that can be put back into the supply chain with
seconds. The more the system gets to know, the little loss of quality. This accuracy is a crucial fac-
better it gets, and this is the reason why auto- tor in the market where sustainability is a distin-
mated plastic sorting systems are continuously guishing factor among brands and industries to
adaptive. be greener and conform to environmental laws.
This is not only more efficient, but it also makes Hyperspectral Imaging: A New Dimension in
the industry and the consumer have an eye- Plastic Separation
catching story. Just think of the power of telling
the tale of a shampoo bottle that is recognized, When NIR sensors can be seen as the new fron-
separated, and pumped back into a different tier, hyperspectral imaging for plastic separa-
bottle production line, all with the help of an in- tion is the new jump into the future. Hyperspec-
telligent camera and a computer code. Already, tral systems, unlike traditional sensors, track a
recycling turns out to be not only a mechanical wide range of data covering hundreds of narrow
procedure but also a wonder of intelligent recy- bands, unlike conventional sensors, which track
cling technologies. one or two specific wavelengths. This forms a
spectral signature of each material in detail, al-
Optical Sorting in Plastic Recycling: Seeing Be- lowing recyclers to distinguish even the most
yond the Surface difficult plastics, including black polymers or mul-
tilayer films.
Optical sorting is the foundation of the current
recycling facilities in plastic recycling. These are Why does this matter? Black plastics commonly
systems based on the light reflection and ab- used in the automobile and electronic industry
sorption pattern recognizing materials. As the are notoriously hard to recycle since they ab-
waste moves past a conveyor belt, light sources sorb most light and are not detected by the
and sensors examine the level of reflection and conventional sensors. These materials can no
absorption of particular wavelengths by indi- longer go unnoticed using hyperspectral imag-
vidual objects. According to this analysis, air jets ing. Recycling plants then suddenly have access
are activated to separate various plastics. to new sources of plastic waste that used to be
discarded in the landfills and turn them into use-
What is really innovative is the use of optical ful raw materials.
sorting and near-infrared (NIR) sensors on plas-
tics. The NIR technology enables machines to One wonders with the use of hyperspectral im-
see even more than visible light can, and the aging for plastic separation: what other invisible
molecular fingerprints of polymers are detected. waste streams this technology may be able to
Human eyes can see a transparent bottle, but reveal? Is it possible to isolate plastics that have
the NIR sensors can immediately identify the additives or trace contaminants with point preci-
chemical composition of the bottle. The magic sion?
lies herein - the separation of plastics not based
64 PLASTICS NEWS October 2025
