Fiber

A fiber is a substance that is significantly longer than it is wide. These long, thin strands are essential building blocks for many different materials. Engineers and manufacturers use fibers to create everything from soft clothing to incredibly strong structures. Because fibers can be engineered to meet specific needs, they are vital to modern technology.

Natural fibers occur through biological or geological processes. They are generally classified by their origin into vegetable, animal, or mineral groups. Vegetable fibers are often based on arrangements of cellulose, which is a complex carbohydrate. Examples include cotton, hemp, jute, and flax. Wood fiber is a specific type of vegetable fiber taken from trees. It is used to make paper and engineered products like fiberboard. To make these products, manufacturers use pulping processes like the kraft or sulfite methods. These processes remove lignin, which is the substance that bonds the original wood structure together.

Animal fibers consist mostly of specific proteins. You can find these in silk from silkworms or wool from sheep. Other examples include hair like cashmere and various types of fur. Biological fibers, also called protein filaments, are very important to living things. These include the collagen family of proteins and muscle proteins like actin. In some cases, genetic mutations in these proteins can lead to severe diseases. Mineral fibers are found in the earth. Asbestos is the only long mineral fiber that occurs naturally. It includes several minerals like chrysotile and amosite.

Artificial fibers are created through human manufacturing. These are divided into semi-synthetic and fully synthetic categories. Semi-synthetic fibers, such as rayon, start with natural materials like cellulose from wood or bamboo. These materials are partially degraded and modified by chemical processes. To make them, the cellulose is turned into a viscous mass. This mass is then pushed through tiny holes called spinnerets to form long strands. This process leaves very few characteristics of the original natural source in the final product.

Synthetic fibers are different because they come entirely from man-made materials. Many of these are derived from petrochemicals through a process called polymerization. Polymerization is a chemical reaction that builds long chains of molecules. Common examples include nylon, which is a polyamide, and polyester. Some synthetic fibers are even more specialized. Carbon fibers are often made by roasting polymers like PAN in a low-oxygen environment. This results in a product that is almost pure carbon. Silicon carbide fibers are another advanced type where silicon atoms replace some carbon atoms.

In the field of engineering, fibers are often used to reinforce plastics. These are classified by their aspect ratio, which is the ratio of length to diameter. Short or discontinuous fibers have an aspect ratio between 20 and 60. Long or continuous fibers have a much higher aspect ratio between 200 and 500. Some fibers are even coated for special functions. For example, silver-coated fibers provide anti-bacterial properties. Aluminum-coated glass is used as radar chaff to confuse radar signals from aircraft.

Microfibers represent a major advancement in textile technology. These ultra-fine fibers were invented in Japan during the early 1980s. They are also known as microdenier fibers. In 1986, the German company Hoechst A.G. began producing them in Europe. By 1990, the company DuPont introduced them to the United States. In textiles, microfibers are defined as being sub-denier. Denier is a measurement used to describe the weight and length of a fiber.

Fibers connect to many different scientific and industrial systems. In telecommunications, optical fibers made from purified natural quartz carry light signals. In fashion, fibers can be shaped into many forms. They can be round, hollow, oval, or even star-shaped. Some fibers are crimped to add bulk to a fabric. The properties of a fiber, such as tensile strength or melting point, determine how it is used. A manufacturer must carefully balance these properties to meet the technical requirements of a specific job.