Technology
Process offers a more
environmentally
friendly alternative to
traditional glass-ceramic
manufacturing
Magic of
microfloat
By Karen Wegert
Commercial architects are demand- ing clear, transparent, smooth, distortion-free and environmentally friendly fire-rated glass-ceramic,
because it o;ers more aesthetically appealing protection. ;e problem: it’s an
incredibly di;cult and energy-intensive
product to make.
Schott,with U.S. o;ces in Louisville, Ky., has found a solution. ;e
company is using an innovative glass-ceramic manufacturing process – called
the microfloat process – to produce
clear, colorless, transparent and wireless
fire-rated glass-ceramic with a smooth,
distortion-free surface. ;is fire-rated
glass-ceramic, Schott Pyran Platinum,
is the only glass-ceramic in the world
produced using this microfloat process.
Figure 1: The smooth, distortion-free surface of Pyran Platinum floated glass-ceramic fire-rated glaz-
ing manufactured using the microfloat process at Schott Technical Glass Solutions GmbH in Jena,
Germany, is evident in this photo of the formed glass ribbon.
How do they do it?
;e unique microfloat process was born
out of the microfloat melt tank at Schott
Technical Glass Solutions GmbH in Jena,
Germany. Schott’s microfloat tank differs from common soda lime float tanks
in both size and process capability. ;e
microfloat tank, as the name implies, has
a smaller output of 20 tons to 50 tons
per day compared to large soda lime float
tanks, which can produce 400 tons to
1,000 tons per day. However, this smaller
output enables the tank to operate at
much higher temperatures and create
more customized glass-ceramic solutions.
Standard glass-ceramic manufacturing
consists of six major processes: melting the
raw materials into liquid glass, forming
the glass into a flat plate, annealing the
glass to remove stress, cutting the glass
into separate sheets, ceramizing the glass
to form an ordered crystal structure,
and cutting the glass into appropriate
glazing dimensions. ;e manufacture of
Pyran Platinum through the microfloat
process begins in much the same way.
Raw materials, such as refined sand and
re-used glass cullet from previous glass-
ceramic melts, are combined to increase
the yield and reduce the required energy
input. ;is raw material batch is then
fed continuously into a melting tank.
