Kapok

Kapok is a natural fiber derived from the seed pods of the kapok tree, Ceiba pentandra, a large tropical tree native to parts of Africa, Asia, and the Americas. The fiber consists of silky, hollow hairs that surround the seeds inside the pod. The hairs are lightweight and buoyant, providing notable loft and insulation.

Properties: Kapok fibers are extremely light and buoyant because they are hollow and air-filled. They are naturally water-repellent, dry quickly, and insulate well. They have good loft but low tensile strength and poor abrasion resistance, so they are not suitable for durable textiles on their own. The fibers are soft to the touch and can decompose naturally.

Production and processing: Harvesting occurs when the seed pods mature; the pods are opened, seeds separated and fibers cleaned. The fiber is typically spun or used as a filler rather than woven into fabrics. In textiles, kapok is often used as a loose insulative fill or blended with other fibers; it competes with synthetic fibers in some markets. It is primarily produced in tropical regions.

Uses: Kapok has long been used as stuffing for pillows, mattresses, and toys, and as insulation for clothing and sleeping bags. It has historically been used for life jackets, buoys, and other flotation devices because of its buoyancy. In some applications, kapok serves as a core filler in lightweight composites.

Ecology and economy: The kapok tree plays a role in tropical ecosystems. Although kapok fiber is renewable and biodegradable, its market has fluctuated due to competition from synthetic fillers and concerns about harvest sustainability in some areas. Research explores blends with other fibers to improve strength and durability.