New spray-on, nanotech coatings could keep iPod screens from
scratching, make paper products waterproof and perform other minor
modern miracles.
And because they are cheaper, easier to apply and more
environmentally friendly than substances currently in use,
nanotechnology-based coatings could replace many of today’s industrial
paints and coatings.
The nano coatings, "liquid solids" composed of extremely tiny
particles, possess unique characteristics — like extreme flexibility,
easy adhesion and resistance to corrosion and microbial growth — that
could profoundly change the manufacturing process.
Sally Ramsey, co-founder and chief chemist of Ecology Coatings,
began exploring the costs and potential environmental benefits of nano
coatings in 2003. She used nano-sized particles of mineral oxides to
create waterproof coatings for paper at half the cost of synthetic
paper. Derivative materials could be used to produce waterproof
cardboard boxes, or integrated into building materials such as drywall
to prevent mold from growing if it becomes wet, Ramsey said.
The wonder coatings also might make small video screens on electronic devices such as iPods and mobile phones more durable.
"Abrasion-resistance and scratch-resistance is very much enhanced"
when the nano coating is applied, according to Ramsey, and surface
hardness is strengthened without losing clarity.
A similar nano coating, licensed from Ecology Coatings by chemical
giant DuPont, could revolutionize the auto parts industry when it is
commercialized, possibly as early as this year.
DuPont hopes to produce nano paint that seals and protects
automotive components, greatly reducing the environmental impact of
producing cars by slashing the amount of energy and materials needed.
The nano-based coating could radically alter the time-consuming and
costly process of applying coatings to auto parts.
The nano particles are small enough to be applied using conventional
spraying equipment, Ramsey said, and the nanotech coating can be cured
simply by exposing the surface of the auto parts to ultraviolet light
for 10 seconds or less.
"After the UV (light) hits it, it becomes a thin sheet of plastic,"
she said. UV curing, which is completed at room temperature, would
replace the standard curing process, which requires placing parts in
ovens at temperatures of up to 400 degrees Fahrenheit for as long as 40
minutes.
Because they eliminate the need for hazardous chemicals currently in
use, the nano coatings also could save parts manufacturers from getting
Environmental Protection Agency permits, tracking emissions and
disposing of solvents.
It all adds up to a more ecologically friendly process with a welcome side benefit: lower manufacturing costs.
According to Bob Matheson, technical manager for strategic
technology production at DuPont, using Ecology Coatings’ nano-based
materials could reduce the cost of applying a coating from "a few dimes
per article down to 1 cent per article or less."
Shifting to nano-based coatings could also change how auto parts are
designed. For instance, engineers could use different materials because
they wouldn’t have to worry about heat from the manufacturing process
melting plastic parts, Matheson said.
"We are in the early stages of a profound industry change," he said.
Matheson said the technology probably would be applied first to "under the hood" parts, such as oil filters or disc brake drums.
DuPont chose products from Ecology Coatings because the technology
is cleaner and less energy intensive than other UV-curable coatings,
Matheson said. He estimates the technology will reduce the amount of
energy used in the coating-application process by 25 percent and reduce
materials costs by 75 percent.
However, UV curing requires exposing the entire surface area of the
part to the light, which is a limitation. And manufacturing plants
would have to be redesigned for the process, replacing rooms engineered
to withstand high temperatures with arrays of UV lights, Matheson said.
Paul Uglum, the appearance technology advocate for auto parts
company Delphi, said his company is beginning to use some UV-curable
paints.
He said heat curing disrupts the manufacturing process. "If you have
parts that are in an oven for half an hour, than you have a huge buffer
of parts waiting to be finished," he said.
Uglum said the energy saved from switching to UV-curable paints
would be significant, since his division of Delphi produces 3.5 million
parts per week. The amount of paint used could be reduced by "thousands
of gallons," he said.
"Being less energy intensive and more environmentally friendly is a
plus," said Charles Griffith, the auto project director at nonprofit
environmental group the Ecology Center.
Auto parts manufacturers may be attracted to the technology because "if
you use non-hazardous materials to start with, then you don’t have the
same regulatory triggers," he said.
However, because the "state of knowledge about some nano particles
is quite immature," Griffith said, "we would need to know about health
studies for the potential impacts of these particles."
John Gartner
