Tensile Fabrics Enhance Architecture Around the World
- Sunday, 01 November 2009
Originating Technology/NASA Contribution
On a Friday night in March 2008, fans at a college basketball game at Atlanta’s Georgia Dome noticed the stadium’s scoreboard begin to sway. Outside, winds howled through the city. Unknown to those in the stadium, a tornado was ripping through downtown. The safety of the more than 18,000 people would depend in large part on the integrity of the stadium’s domed roof—built using a material originally developed to protect NASA astronauts.
Over 40 years earlier, NASA’s effort to achieve the first manned Moon landing nearly derailed when a fire broke out on the Apollo 1 command module during a test exercise, resulting in the destruction of the module and the deaths of the three astronauts onboard. In the wake of the tragedy, NASA engineers redesigned the Apollo module and searched for ways to enhance the safety performance of the nylon space suits. The suits required an outer layer component that would be durable, strong, lightweight, flexible, and noncombustible. Owens-Corning Fiberglass, of Toledo, Ohio—working with DuPont, of Wilmington, Delaware—proposed a fabric known as “Beta cloth.” The primary component of this fabric was ultrafine glass filaments, which were twisted into yarns and then woven into the fabric. The manufacturers then coated it with polytetrafluoroethylene (PTFE, more commonly known as Teflon), a DuPont invention. The fabric proved noncombustible (with a melting point over 650 °F) and durable enough for NASA’s needs. The Agency incorporated the PTFE fiberglass fabric into the outer protective layers of the Integrated Thermal Micrometeoroid Garment (ITMG) of the A7L space suit worn for the Apollo missions and Skylab program. The PTFE fiberglass fabric layer provided both thermal protection as well as shielding from abrasive lunar dust during Moon landings.
While the current NASA space suit used on the space shuttle and International Space Station employs Ortho-Fabric (a blend of GORE-TEX, Kevlar, and Nomex—all private industry inventions) in its ITMG instead of the PTFE fiberglass fabric, that original innovation has gone on to become a unique component of an unrelated, terrestrial field: architecture.
In 1956, aeronautical engineer Walter Bird founded Birdair Structures Inc. in the kitchen of his home in Buffalo, New York. Birdair initially focused on air- supported, neoprene-coated nylon fabric structures, building upon its founder’s experience crafting such structures for use by the U.S. military.
Birdair’s work developing the air-supported, vinyl-coated fiberglass fabric roof (the first of its kind) of the U.S. Pavilion at Expo 1970 in Osaka, Japan, led the company to explore improved fiberglass fabric options for architectural use. The company collaborated with Owens-Corning, DuPont, and Chemical Fabrics Corporation (Chemfab), of Merrimack, New Hampshire on a modified, stronger version of the PTFE glass fiber fabric developed for NASA. The resulting fabric (later called Sheerfill Architectural Membrane, manufactured by Chemfab), expanded the market for Birdair in the field of lightweight, tensile membrane roof structures for roofs, skylights, and canopies.
“When there are so many architectural materials out there, fabric is not something architects usually think of offhand,” says William Barden, Birdair’s director of architectural development. “Walter Bird’s pioneering role in the tensile structure industry was to take a technology that was perceived by people as ‘pie in the sky’ and create a market for it.”