Page 47 - Plastics News April 2021

teChnoLogy

Tracking pervasive microplastics

esearcher Janice Brahney from the Department of Watershed Sciences, S.J. & Jessie
RE. Quinney College of Natural Resources, Utah State University has come up with
a study that says plastics travel and works on a bigger scale than one could think of.
Understanding how microplastics move through global systems is essential to fixing the
problem, said Brahney. Her new research focuses on how these invisible pieces of plastic
get into the atmosphere, how long they stay aloft, and where in our global system we can
expect to find hotspots of microplastic deposition. According to her the plastic straw you
discarded in 1980 hasn't disappeared; it has fragmented into pieces too small to see, and
is cycling through the atmosphere, infiltrating soil, ocean waters and air. Microplastics
are so pervasive that they now affect how plants grow, waft through the air we breathe,
and permeate distant ecosystems. They can be found in places as varied as the human
bloodstream to the guts of insects in Antarctica. Plastics enter the atmosphere ... not
directly from garbage cans or landfills as you might expect ... but from old, broken-down waste that makes its way
into large-scale atmospheric patterns. Roads are a big source of atmospheric plastics, where vehicle tires churn and
launch skyward the tiny pieces through strong vehicle-created turbulence. Ocean waves, too, are full of insoluble
plastic particles that used to be food wrappers, soda bottles, and plastic bags. These "legacy plastic" particles bob to
the top layer of water and are churned by waves and wind, and catapulted into the air. Another important source for
the re-emission of plastics is dust produced from agricultural fields. Once in the atmosphere, plastics could remain
airborne for up to 6.5 days -- enough time to cross a continent, said Natalie Mahowald, coauthor on the paper. The
most likely place for plastic deposition from the atmosphere is over (and into) the Pacific and Mediterranean oceans,
but continents actually receive more net plastics from polluted ocean sources than they send to them, according to
the models. The U.S., Europe, Middle East, India and Eastern Asia are also hotspots for land-based plastic deposition.
Along the coasts, ocean sources of airborne plastic become more prominent, including America's west coast, the
Mediterranean and southern Australia. Dust and agriculture sources for airborne plastics factor more prominently in
northern Africa and Eurasia, while road-produced sources had a big impact in heavily populated regions the world over.
This study is important, said Brahney, but it is just the beginning. Much more work is needed on this pressing problem
to understand how different environments might influence the process ... wet climates versus dry ones, mountainous
regions versus flatlands. The world hasn't slowed its production or use of plastic, she said, so these questions become
more pressing every passing year.

Glassomer injection molding technology

or the first time, a team led by Prof. Dr. Bastian E. Rapp from the Laboratory of
FProcess Technology at the Department of Microsystems Engineering at the University
of Freiburg, in collaboration with the Freiburg-based start-up Glassomer, has developed
a process that makes it possible to form glass easily, quickly and in almost any shape
using injection molding. The researchers presented their results in the journal Science.
"For decades, glass has often been the second choice when it comes to materials in
manufacturing processes because its formation is too complicated, energy-intensive and
unsuitable for producing high-resolution structures," explains Rapp. "Polymers, on the other
hand, have allow all of this, but their physical, optical, chemical and thermal properties
are inferior to glass. As a result, we have combined polymer and glass processing. Our
process will allow us to quickly and cost-effectively replace both mass-produced products
and complex polymer structures and components with glass." Injection molding is the most

47 April 2021 Plastics News