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Before threads can be woven into textiles, they are usually
“sized”—coated with a liquid which strengthens and smoothes the thread so
that it can survive high-speed weaving. Dipping the threads into hot solutions
of starch or polyvinyl alcohol, then drying them, is messy and energy-intensive,
so researchers at the Idaho National Engineering and Environmental Laboratory
have replaced this 19th-century technology with thin tubes containing the same
sizing fluids at very high pressure. The pressure forces this “supercritical”
fluid into the threads as they pass through, emerging seconds later, finished
and dry. The technique reduces the amount of sizing fluid and rinse water
needed.