It can better withstand explosions

Sep 11, 2009 07:42 GMT  ·  By

Experts from the University of Missouri-Columbia (UMC) have recently announced the creation of a new type of blast-resistant glass, which they advertise as being much more efficient in absorbing and reducing the impact strength of explosions than the existing varieties already on the market. The new material will also be thinner, lighter and cheaper than its more bulky counterparts, and will arguably be able to withstand small-scale explosions better, its developers say.

Average bullet-proof and blast-resistant glass is very thick and expensive, and made up of intertwining sheets of plastic and glass. They are also very cumbersome to handle and install, but people use them because they have no other choice.

“Currently, blast-resistant window glass is more than 1 inch thick, which is much thicker than standard window glass that is only one-fourth of an inch thick and hurricane-protected window glass that is one-half of an inch thick. The glass we are developing is less than one-half of an inch thick. Because the glass panel will be thinner, it will use less material and be cheaper than what is currently being used,” UMC College of Engineering Associate Professor of Mechanical and Aerospace Engineering Sanjeev Khanna explains.

In their approach, the experts replaced the sheet of plastic in the middle of average blast-resistant windows with a layer of transparent, composite material made of plastic-embedded glass fibers. The advantage of the new materials is the fact that they are only 25 microns thick each, which is roughly equivalent to half of the width of a human hair. This means that, overall, there is a smaller room for defects in the material that could lead to its cracking when sufficient force is applied.

In experiments, grenades and hand-delivered bombs were exploded in close proximity to the new type of glass. The experts indeed found signs of cracking in the layers of glass, but the composite layer had not been breached. Khanna says that, “The new multilayered transparent glass could have a wide range of potential uses if it can be made strong enough to resist small-scale explosions. The super-strong glass also may protect residential windows from hurricane winds and debris or earthquakes. Most hurricane damage occurs when windows are punctured, which allows for high-speed wind and water to enter the structure.”

The US Department of Homeland Security (DHS) Science and Technology Directorate funded the new study with a $250,000 grant. Plans are now to expand the experiment to pieces of glass the size of average windows, and then to test them against large-scale explosions.

To protect from potential terrorist attacks, federal buildings and other critical infrastructures are made with special windows that contain blast-resistant glass. However, the glass is thick and expensive. Currently, University of Missouri researchers are developing and testing a new type of blast-resistant glass that will be thinner, lighter and less vulnerable to small-scale explosions.

Video credit: Cooperative Media Group