STICKY SITUATION: X-FLEX is applied to the interior side of exterior walls much like wallpaper and designed to absorb the shock of an explosion, mitigating the danger of concrete pieces turning into projectiles. Image: Image courtesy of Berry Plastics Corp., Tapes & Coatings division
The Army has developed a new material designed to keep walls from blowing apart and sending fragments flying at high speed during explosions. The X-FLEX Blast Protection System, a wallpaperlike adhesive-backed tape developed by the U.S. Army Corps of Engineers' Engineer Research and Development Center (ERDC) and Evansville, Ind.–based Berry Plastics Corp.'s Engineered Protective Systems division, is applied to walls and designed to absorb the shock of a blast, protecting occupants from flying concrete and metal turned into projectiles.
X-FLEX is made from a polymer composite laced with reinforcing fibers that make it strong yet flexible. The material is applied by wiping away dust or particles from the wall surface, peeling away a protective film liner and pressing the tape against the wall. The wall may be coated with a water-based primer, developed by Berry, after cleaning to reduce the time it takes for the adhesive to stick to the concrete. The material is further secured at the top and bottom with fasteners to ensure it stays in place if hit by an explosion.
"The material is placed on the interior side of exterior walls and intended to protect the occupants of that particular room," says Elizabeth Curran, business development manager in Berry's Tapes and Coatings division in Franklin, Mass.
Berry began working with the Army in 2005 to design an adhesive-backed composite tape that would hold together during a blast, Curran says.
The Defense Department's interest in such a material dates back to before September 11, 2001. In fact, it had already begun applying a reinforcing material to areas of the Pentagon prior to the attack, says Pamela Kinnebrew, technical director for the Survivability and Protective Structures division within ERDC's Geotechnical and Structures Laboratory in Vicksburg, Miss. Kinnebrew would not provide details on where or how much of the Pentagon had been reinforced, nor would she describe the material used other than to say that it was not X-FLEX.
The Army is looking to purchase so-called "off the shelf" supplies made by commercial manufacturers rather than producing all of its technology in-house. "We can buy these materials and put them in the lab, but ultimately, for them to be of use to the war fighter we have to have a manufacturing capability," Kinnebrew says. She would not divulge whether U.S. soldiers in Afghanistan or Iraq are using X-FLEX at this time on military installations.
In the wake of the Mumbai attacks last month, it's clear that other types of potentially vulnerable establishments might also benefit from such safeguards. Berry says it plans to make similar products available to commercial businesses. "If we want to sell to a hotel, for example, it [X-FLEX] would be sold under a different name and modified to meet that industry's specific needs," Curran says, adding that she would not estimate how much such a product would cost.
Given the demand for technology to protect military personnel in combat, ERDC is also developing a $10-million modular protective system that it claims in a promotional video is made from material "10 times stronger than concrete." The system would allow soldiers to construct temporary structures or reinforce existing ones with walls consisting of a double layer of armored panels held together by a collapsible frame.
Outside the U.S., a team of Norwegian researchers is testing another option: lightweight aluminum panels that can be filled with densely packed dirt, gravel, sand or any other readily available substance to provide protection without adding a lot of weight to military vehicles or structures. The aluminum panels are designed to easily fit together and filler is emptied out at the bottom before they are moved.