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Firefighters’ clothing is bulkier than it needs to be, says Gore Enterprises
of Newark. Emergency suits have an outer layer of woven Kevlar for strength and
a laminated inner layer to keep out hot fluids. A thick quilted lining provides
insulation, but it is heavy and bulky. Gore’s new suit is normally thin and
comfortable, but puffs up to give extra protection when the temperature rises.
The air gap between the layers contains bimetallic strips that change shape with
temperature. At a safe 21 °C, the gap is just 4 millimetres. The spacers
expand as things hot up and at 100 °C they create a 17-millimetre gap. When
it cools, the material goes back to its original thickness (WO 99/05926).