Along with the water vapor evaporated from the wet clothes, the exhaust stream carries lint – highly flammable particles of clothing made of cotton and polyester – through the ventilation duct. Lint can accumulate in the exhaust duct, reducing the dryer's ability to expel the heated water vapor, which then accumulates as heat energy within the machine. As the dryer overheats, mechanical failures (thermostat, limit switch, damaged screen, or crushed hose) can trigger sparks which cause the lint trapped in the dryer vent to burst into flames. |