How did the switch from natural to synthetic fibers come about? Until 1940, U.S. parachutes were made of silk, a natural fiber of animal origin (it is produced by silkworms) that has characteristics of strength and lightness. However, Japan banned the United States from importing silk from China, and the United States had to create a new material, nylon, a polyamide that is obtained by polymerization and has characteristics very similar to silk. Women also benefited from this discovery from that time on, as they were able to replace silk stockings with much stronger nylon ones, a real revolution.
Since 1940, therefore, it has been all about the successes of chemistry in the field of fibers.
Textile fibers are classified into natural fibers if they come from products of plant origin, such as cotton and linen, or animal origin, such as wool and silk, and technofibers or chemical fibers those that are chemically synthesized.
Technofibers, in turn, are divided into man-made fibers if they are made from organic polymers such as cellulose, i.e., from renewable raw materials, and are absolutely comparable to natural fibers, and synthetic fibers if they are made by chemical synthesis, including from recycled raw materials and biomass, through polymerization reactions.
Technofibers, compared to natural fibers, can be produced with any desired characteristics: elastic or stiff, unalterable or delicate, bright or dull, colored or transparent fibers can be obtained. All these possible characteristics mean that, worldwide, 60 percent of the textile fibers used are man-made fibers. And yet, the flipside of the coin lies in the fact that they are not biodegradable, and these wastes are also becoming a problem in landfills and, because of the microplastics that are released in washings, in the oceans as well.
Invented in 1883 by a French chemist, viscose is the progenitor of man-made fibers, covering 14 percent of industrially produced fibers. Initially viscose was called vegetable silk, then called rayon, and finally today in different ways depending on whether it is extracted from plant-derived cellulose (cellulosic viscose) or from proteins of animal, plant materials or food production waste (protein cellulose). Viscose has the characteristic of being soft to the touch and very bright because it absorbs colors well. It is pleasant to wear being a breathable fiber and, because it prevents the growth of bacteria, it is hypoallergenic. Above all, it is biodegradable.
Efforts are being made to create environmentally friendly plant viscoses such as modal and lyocell for the production of which natural fibers and chemicals are used so as to obtain materials that have a good portion of natural component.
Modal is a man-made fiber of the viscose family, which is derived from a fiber regenerated from cellulose that is extracted from the pulp of beech trees. Modal fabrics have some success due to their softness, which is particularly pleasant to the touch. In fact, it is added to cotton to impart greater hygroscopicity and quality.
Lyocell is an environmentally friendly plant fiber extracted from the cellulose of eucalyptus trees. Despite its origin, lyocell is not a natural textile fiber, but absolutely artificial because it is produced in a laboratory using chemicals. Lyocell T-shirts are the best-selling garments made from this fabric because of its hygroscopicity and for being particularly soft and pleasant to the skin.
Among the most widely used synthetic fibers in textiles is polyester, a polymer derived from recycled and waste materials and bacterial fermentation. It is the fabric of sportswear because it has almost infinite durability, allows the skin to breathe, and is lightweight. Because it releases microplastics with each wash, how to make it environmentally friendly is being investigated. One proposed way might be to stop making new ones and use only recycled ones until they run out.
ACTIVITY: Do an Internet search on the history of textile fibers and create a chart on their use in Italy.