Sheep wool

Sheep wool is a textile raw material from the fleece of domestic sheep. Sheep live for 10–12 years, and each animal can produce at least 3 kg of wool annually, with some breeds providing up to 18 kilograms. Wool is shorn once or twice a year (a skilled shearer can shear over 20 sheep per hour). The shorn wool is stored as a whole fleece, the different parts of which are later classified into specific quality grades.

Raw, greasy wool contains on average less than half the weight of spinnable fibers, with 10–45% being grease and sweat, 5–20% are impurities that got into the fleece in the pasture, and the fibers can absorb up to 25% moisture. Grease and sweat are removed by washing (the obtained lanolin can be used in cosmetics), and plant impurities are carbonized (carbonization of wool) with sulfuric acid (charred). The pure fiber consists of keratin, pigment, and chemically bound moisture. Among the chemical elements, carbon represents 50%, with the next 40% being oxygen and nitrogen. The fiber surface is scaly. The unique chain molecule structure gives the fiber excellent elasticity and flexibility (E-modulus). Wool, therefore, tends to be almost wrinkle-resistant but also less strong compared to other textile fibers, losing an additional 10–20% of its strength when wet. Dyeing two batches of wool to an exactly identical shade is hardly possible. Wool products must be protected against moths. Wool is significantly more expensive than ordinary textile fibers.

In assessing wool quality, important factors include length, strength, content of plant impurities, color shade, and crucially, fiber fineness. Fineness is currently understood as the thickness of the fiber cross-section measured in micrometers (µm). Until the late 20th century, fineness was also identified by the so-called "Bradford system" with a spinning count/wool grade number. The designation of wool fineness by the Bradford system is still used (as of 2012) in some Asian countries. In the USA, an ordinance effective from January 1, 2007, determines the labeling for average fiber fineness in products made from pure wool (and blends with over 45% wool content) according to rules derived from the Bradford system. There is also the term Super Bale - for the bale of the finest wool in the world, sufficient for only about 40-50 suits. It is auctioned, and leading processing companies (e.g., Loro Piana) are interested in it.

The world production of greasy wool reached approximately 1.2 million tons in 2014/15. The three largest producers (Australia, China, and New Zealand) supplied more than half for textile processing (the Czech Republic was the 4th largest wool importer in the world in 2006). However, about 40% fewer fibers reach spinning after grease and impurities have been removed, so the average per capita consumption was less than 200 grams, and wool's share in raw materials for the textile industry was less than 2%. While the total consumption of textile fibers nearly doubled in the last 20 years, wool consumption in that period decreased by about 40%.

Virtually all wool fiber production is processed by two basic technologies: Combed (including semi-combed) yarn production and carded yarn production. Exceptionally, wool is blended with cotton for the production of ring or rotor yarns using cotton technology. All yarns need to be wound and mostly twisted, as the strength of single yarns is usually sufficient only for some knitting purposes and as weft. A significant by-product of sheep wool is lanolin, a chemically complex, waxy fat primarily composed of cholesterol, esters, and several fatty acids. It is used in cosmetics (softens and smooths the skin; various creams), in the textile industry (softener; added to some detergents), in the leather industry, in medicine, and pharmacology (antibacterial and hypoallergenic; promotes healing of minor burns; used for vitamin D3 production).