Compiled by Juli Case
We’ve been asked to make a blast curtain. Where can we find material that’s rated GSA 3B?
After the Oklahoma bombing and the 9/11 terrorist attacks, it was realized that some of the damage caused by an explosion is from flying glass and other debris. As a result, in January 2003 the USA General Services Administration (GSA) developed a rating system for the performance conditions of window system responses. The performance condition of 3B has a protection level of high and a hazard level of low. The description of the window response is: “Glazing cracks. Fragments enter space and land on floor no further than 10 feet from the window.”
The GSA 3B rating, however, is for an entire window system, including the glass, the frame and items such as blast curtains. In fact, the title of the document is “US General Services Administration Standard Test Method for Glazing and Window Systems Subject to Dynamic Overpressure Loadings.” A fabric can contribute to the finished window systems rating, but is not itself rated 3B. Our research showed that high-tenacity polyester or olefin knit fabrics are used in blast curtains, as well as high-tech materials such as auxetic fiber technology.