Fiber

Fiber is a term for a slender, flexible strand with a high length-to-diameter ratio. Fibers can be natural, such as cotton, wool, or flax, or manufactured, such as polyester, nylon, glass, or carbon. They are used for textiles, reinforcement in composite materials, insulation, and cables.

Dietary fiber refers to plant-based carbohydrates that resist digestion. It is categorized as soluble fiber, which forms gels, and insoluble fiber, which adds bulk to stool. Common sources include fruits, vegetables, whole grains, legumes, and nuts. Benefits include improved bowel function, better blood glucose and cholesterol control, and reduced risk of certain diseases. Typical adult goals range from about 25 to 38 grams per day, increasing gradually with fluids to prevent discomfort.

Industrial fibers fall into natural and synthetic groups. Natural fibers such as cotton, linen, wool, and hemp are valued for comfort, breathability, and biodegradability. Synthetic fibers such as polyester, nylon, and acrylics are engineered for strength and durability. Special fibers like glass and carbon provide high stiffness for composites and aerospace applications. Fibers are usually formed into yarns, rovings, or mats and processed by weaving, knitting, or extrusion.

Optical fiber is a strand of glass or plastic that transmits light for communications. It consists of a core surrounded by cladding with a lower refractive index, enabling total internal reflection. Optical fibers enable high-bandwidth data transmission over long distances and form the backbone of modern telecommunications.