Kapok (fiber)

Yellowish brown, lightweight seed-hair fiber obtained from the fruit of the species Ceiba pentandra. The highly inflammable, soft fibers have a smooth surface and are transparent. The fibers contain both lignin, a woody plant substance, and cellulose, a carbohydrate. Kapok is buoyant and will support up to 30 times its own weight. Although the fluffy fibers are too brittle to spin, they are used for filling mattresses, upholstery, life jackets, as insulation material, and as a substitute for absorbent cotton in surgery.