Anyone sitting in this GLASS HOUSE is welcome
to throw stones
BMW is offering laminated safety glass side windows
as an extra with its Series 7 model. The glass is produced by DuPont using
SentryGlas Plus ionoplast interlayers. This innovative form of glazing by
Pilkington in Munich/Germany is said to withstand even high impacts, offering
improved passenger safety and protection against break-ins. The windows are
nonetheless highly transparent and noticeably thinner than traditional safety
glass side windows.
 |
BMW is offering side windows made from thin laminated safety glass as an extra with its Series 7 model. The panes of glass can withstand even high impacts, which makes it that much more difficult even for the most determined car thief. (photo: DuPont) |
This innovation is the result of a four and a half year
joint development project carried out by Pilkington and BMW, during which
DuPont assisted in adapting the properties of SentryGlas Plus, used successfully
in the building industry, to the requirements of the car manufacturers.
Earlier BMW models used safety glass side windows made from a 9 mm thick interlayer
of polycarbonate plastic. The laminated safety glass is only 5.6 mm thick
(consisting of inner and outer layers each of 1.8 mm thick prestressed glass
sandwiching 2 mm of SentryGlas Plus), enabling the car maker to incorporate
the side window structure into the standard door and sealing systems, not
only improving safety but also reducing costs.
Thinner but more effective
According to Gerald Buck, head of the glazing construction division at BMW
“The level of protection afforded by the ionoplast option is 75% as effective
as that of the earlier much thicker side windows. We can therefore meet the
BMW intrusion resistance specifications in full.” In further tests conducted
by BMW, the SentryGlas Plus side windows withstood impacts from a heavy implement
for more than two minutes.
The product is available in panel form, is tough, rigid and humidity resistant
and offers outstanding optical clarity. Glass manufacturers laminate it between
two panes of glass, to which it becomes firmly adhered. It tends not to become
blocked during manufacture, it can be easily stacked, and is suitable for
manufacture in traditional PVB/glass lamination plants. It is said to offer
almost one hundred times the rigidity of PVB interlayers and five times the
tear resistance. If a car side window does indeed shatter, whether due to
an accident or deliberate damage, the glass shards will be held by the interlayer,
thereby reducing the risk of injury.
www.dupont.com