If you look closely at the pictures associated with the story (and rtfa), and provided on the company website you see something interesting. The fibers don't actually get wider, as they claim, they stay the same size when stretched (measure from top to bottom of the pieces of fabric in the pictures). However, due to the nature of the co-wound materials, pores open up within the fabric, which they claim allows the air associated with blasts to pass through, while preventing shrapnel/debris from passing. They talk about seat-belts etc getting wider, but they show no examples of this behavior.
Slashdot Mirror
If you look closely at the pictures associated with the story (and rtfa), and provided on the company website you see something interesting. The fibers don't actually get wider, as they claim, they stay the same size when stretched (measure from top to bottom of the pieces of fabric in the pictures). However, due to the nature of the co-wound materials, pores open up within the fabric, which they claim allows the air associated with blasts to pass through, while preventing shrapnel/debris from passing. They talk about seat-belts etc getting wider, but they show no examples of this behavior.