Soon, blast-resistant glass that can withstand force of explosion

WASHINGTON - To withstand the force of an explosion, earthquake, or hurricanes winds, a team of engineers from the University of Missouri and the University of Sydney in Australia are working to develop a blast-resistant glass that is lighter, thinner, and colorless.

But current blast-resistant glass technology is thicker than a 300-page novel-so thick it cannot be placed in a regular window frame. This makes it very difficult-and expensive-to replace standard glass windows in present structures.

Unlike today’s blast-resistant windows, which are made of pure polymer layers, this new design is a plastic composite that has an interlayer of polymer reinforced with glass fibers-and it’s only a quarter-inch thick.

The project team recently subjected their new glass pane to a small explosion.

“The results were fantastic,” exclaimed Sanjeev Khanna, the project’s principal investigator and an associate professor of mechanical engineering at Missouri.

“While the discharge left the pane cracked, the front surface remained completely intact.”

The secret to the design’s success is long glass fibers in the form of a woven cloth soaked with liquid plastic and bonded with adhesive. The pane is a layer of glass-reinforced clear plastic between two slim sheets of glass. Even the glue that holds it all together is clear.

The glass fibers are typically 15 to 25 micrometers in diameter, about half the thickness of a typical human hair. The small size results in fewer defects and a decreased chance of cracking. The strong glass fibers also provide a significant reinforcing effect to the polymer matrix used to bind the fibers together. The more fibers used, the stronger the glass reinforcement.

And while traditional blast-proof glass usually has a greenish ting, special engineering renders the polymer resin transparent to visible light.

Engineers expect the new design will be comparable in cost to current blast-proof glass panes, but lighter in weight. At only a quarter-inch thick, this newly engineered composite would slip into standard commercial window frames, making it much more practical and cost-efficient to install.

“Designing an affordable, easy-to-install blast-resistant window could encourage widespread use in civilian structures, thereby protecting the lives of occupants against multiple threats and hazards,” noted John Fortune, manager of the project for the Infrastructure and Geophysical Division at S and T.(ANI)