Chemical Engineering June 2016 - 18

Schott Glass
cently teamed with Ford motor Co.
to use Gorilla glass for the front and
rear windshields on the Ford GT
sports car.
The toughened glass is made by
being immersed in a molten alkaline
potassium salt at a temperature of
about 400°C. here the smaller sodium
ions in the glass are replaced
by larger potassium ions from the
salt bath. The larger ions occupy
more space and thus create a surface
layer of high residual compressive
stress at the surface, giving the
glass surface increased strength,
the ability to contain flaws, and
crack-resistance.
other glass makers that have deFigure
2. Schott Glass received the German Industry Innovation Award 2016 for its ultra-thin, flexible glass
comes transparent again.
The glass stops solar heat gain,
blocks glare, reduces fading, and
eliminates the need for window
shades and awnings, while allowing
building occupants to continually
view the outdoors.
EControl works in a manner similar
to that of a traditional solar control
and thermal control glass. With
EControl, the outer pane of an insulating
glass is replaced by an electrochromic
laminated pane. This basic
construction can be combined with
additional functions, such as security
glazing.
Another type of smart glass technology
is used in suspended particle
devices (SPDs). In these devices, a
thin film laminate of rod-like nanoscale
particles is suspended in a liquid
and placed between two pieces
of glass or plastic, or attached to
one layer. Normally the suspended
particles are randomly positioned,
blocking and absorbing light. When
a voltage is applied, the particles
align and allow the light to pass
through. Varying the applied voltage
can control the particles' orientation,
thus controlling the tint of
the glazing and the amount of light
transmitted. SPDs can also control
the amount of heat passing through,
reducing the need for air conditioning
or heating.
Companies offering SPD smart glass
18
include AGC, Asahi India Glass ltd.
(mumbai, India; www.aisglass.com),
and research Frontiers Inc. (Woodbury,
N.Y.; www.smartglass.com).
Flexible glass. A few companies
offer a flexible, ultra-thin glass that
can bend to such an extent that you
can almost wrap it around your finger
without breaking it. Such glass
can be used in displays to make
thinner and lighter portable devices,
such as smartphones and tablets. It
can be used as cover glass in flexible
olED (organic light emitting
diode) displays, and as substrate
material for thin-film batteries. It
can also be used in communications
to process data up to eight
times faster than was previously
possible. Companies offering such
glasses include Corning, Inc. (New
York; www.corning.com), whose
thin flexible glass is called " Willow
Glass " ; and Schott AG (mainz, Germany;
www.schott.com).
According to John mauro, senior
research manager at Corning, the
most successful of his company's innovations
is " Gorilla glass, " a brand
of toughened glass, now in its fifth
generation, designed to be thin, light
and damage-resistant. The alkalialuminosilicate
sheet glass has been
used mainly as cover glass for portable
electronic devices such as mobile
phones, portable computer displays,
and television screens. Corning reveloped
similar glass include Asahi
Glass and Schott. Asahi Glass'
toughened glass is called Dragontail
glass and Schott's is called
xensation, and both are also alkali-aluminosilicate
sheet glass with
properties very similar to those of
Gorilla glass.
Glassmaking innovations
Apart from the many innovations in
glass products, there have also been
important developments in the glass
manufacturing methods.
late last year, Praxair, Inc. (Danbury,
Connecticut; www.praxair.
com) demonstrated a thermochemical
regenerator system at a glassmaking
facility in mexico. Known as
optimelt, the heat-recovery system
lowers fuel consumption in oxy-fuel
furnaces, which use pure oxygen instead
of air as the primary combustion
oxidant (for more details about
optimelt, see Chem. Eng., December
2015, p. 7).
In April, Praxair signed a contract
with libbey, Inc. (Toledo,
ohio; www.libbey.com), one of the
largest glassware and tableware
manufacturers, to supply it with
the optimelt system. Praxair also
entered into a contract with libbey
to deliver o2 to its glass melting facility
in the Netherlands through a
non-cryogenic, vacuum pressureswing
adsorption (VPSA) system.
both the optimelt system and the
VPSA supply system are scheduled
to start up in 2017.
n
Paul Grad
ChemiCal engineering www.Chemengonline.Com june 2016

http://www.aisglass.com http://www.smartglass.com http://www.praxair http://www.corning.com http://www.schott.com http://www.libbey.com http://www.Chemengonline.Com

Chemical Engineering June 2016

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