Nanotechnology: The next big thing to hit plastics
Canadian PlasticsPlastics Processes Injection Molding: Technology Advances
For many of us, nanotechnology is probably a bit like Einstein’s theory of relativity: we’ve hea...
For many of us, nanotechnology is probably a bit like Einstein’s theory of relativity: we’ve heard of it, we know it affects us, but we don’t really understand how.
It turns out, though, that nanotechnology is already having an impact on the plastics industry. For the processor, a key benefit is this: through nanotechnology, special nanocomposites can be created that, when applied to plastics, create parts that are better in a variety of ways, yet cheaper to manufacture.
And that’s just the beginning.
WHAT’S A “NANO”, ANYWAY?
If you’re not quite sure what nanotechnology is, don’t worry – you’re not alone. “A lot of very intelligent people don’t understand nanotechnology,” said Don Rosato, a senior research analyst, plastics, at Frost & Sullivan in Concord, Mass. “They see the prefix ‘nano’ – which is Greek for dwarf – and know that it involves something very small, but beyond that the whole process seems mysterious.”
Nanotechnology is, in fact, a very broad, highly heterogeneous field of technology. As an enabling technology, it sets the stage for various innovations in many fields, ranging from the automobile industry to the electronic industry and the pharmaceutical industry. The word “nanotechnology” describes materials, structures and technologies involving the creation or presence of a spatial dimension smaller than a hundred nanometers. “A single nanometer is one millionth of a millimeter,” Rosato said. “To put that in perspective, the diameter of a human hair is about 50,000 nanometers.”
At this very tiny level, the chemical, physical and biological properties of materials are different than when in their bulk form, and often behave differently compared to traditional materials, including polymers. For the manufacturing world, here’s where it gets exciting: the special properties of these microscopic particles can be used to develop materials that offer significant advantages in our macroscopic world, including improved strength, mechanical toughness, UV resistance and barrier thermal electrical conductivity.
For the plastics industry, nanotechnology basically means nanocomposites that are compounded into a plastic. “The big advantages to using nanomaterials in plastics products are getting more performance at lower cost and more efficient material levels,” said Rosato. “The ability to give higher performance than is possible with traditional material properties is already well known: for example, if you put a nanoclay in an auto running board or bumper, you’ll get more impact resistance for a longer period of time at a lower loading level than materials like TPOs can offer.”
MORE THAN JUST TOUGH
Toughness isn’t the only benefit to nanotechnology. According to a recent report on nanoscale science by the Committee on Technology, National Science and Technology Council, many plastic applications currently in use can be reduced further in size while improving efficiency. “Memory chips the size of a postage stamp, yet capable of holding the data equivalent to 25 DVDs, is on the horizon through the use of nanotechnology,” the report said. “Similarly, solar panels that can be manufactured at a much lower cost then they currently are may be able to be produced with nanotechnology.”
Plastic nanotubes are also being created with nanotechnology. These nanocomposites are generally 50 to 150 nanometers in diameter and are used to conduct electricity. While these nanotubes have the current carrying capacity of copper, they’re extremely flexible, lightweight and durable. This technology is expected to be able to lead to the creation of conductive paints, caulks, coatings, sealant, fibers and adhesives. The thick sheets and tubes are also considered to be potentially valuable to the automotive, aerospace and chemical industries.
Finally, special nanocomposite foams have already been created. Over time, these foams will likely replace solid plastic because they’re much lighter, yet look the same as solid plastics. Potential uses for foam nanocomposites include coffee cups, fast food containers, home insulation, carpet padding, disposable diapers, seat cushions and packaging material.
Nanotechnology is also a hot topic with government and academic researchers. “It’s an area that receives a good deal of government funding,” said Don Rosato. “Most universities, including several in Canada, are doing research with nanotechnology.”
MATERIAL SUPPLIERS GET ONBOARD
This growing acceptance is reflected in the large number of plastics material suppliers delving into the field. “There might have been 200 end use plastics products made through nanotechnology available in 2006,” Rosato said. “Today, there are approximately 600. Among the global material suppliers, all of the heavy-hitters – BASF, Bayer, DuPont, Dow, Sabic Innovative Plastics, Lanxess, DSM and Clariant – are getting more involved.”
To use just one example, Clariant Masterbatches is currently cooperating with several German companies in a project designed to use carbon nanotube technology (CNT) to help reduce the cost of environmentally friendly, low-temperature fuel cells. “Applications that involve carbon nanotubes have been experiencing enormous growth because of the material’s unique properties, which include exceptional electrical conductivity, strength and stiffness,” said Dr. Ralph Rutte, head of production and technology, Clariant Masterbatches Division, Muttenz, Switzerland. “Using CNTs in place of conventional graphite fillers and carbon black in fuel cell plates is expected to provide better conductivity. The benefit for the plastics manufacturer is that, by processing the CNT materials compounds on standard injection molding machines, they can reduce production costs while increasing productivity.”
But if the future of nanotechnology in plastics appears unlimited, it turns out that there are still some hurdles to jump. For example, critics of nanotechnology maintain that certain substances may become toxic when manipulated at such a small scale. There’s also fear that some of these manipulated substances could cause harm to the immune system if inhaled, absorbed through the skin, or otherwise digested – a possible blow to medical molders hoping to incorporate nanocomposites into their products. “There is a potential for nanoparticles in medical applications to cross the blood/brain barrier,” said Don Rosato. “It’s a problem that researches are working on, but don’t yet know how to solve.”
These challenges notwithstanding, there’s no doubt that decision-makers in the plastics materials industry are embracing nanotechnology with open arms. As Dr. Andreas Kreimeyer, a member of the board of directors at BASF, put it, “the deeper understanding of relationships at nanodimensional level enables us to use new effects systematically and safely, and to develop products that even more effective for continued profitable growth in expanding markets and as a basis for tapping into new markets.”