Wool

Wool before processing
Unshorn Merino sheep
Shorn sheep

Wool is the textile fiber obtained from sheep and other animals, including cashmere and mohair from goats, qiviut from muskoxen, from hide and fur clothing from bison, angora from rabbits, and other types of wool from camelids;[1] additionally, the Highland and the Mangalica breeds of cattle and swine, respectively, possess wooly coats. Wool consists of protein together with a few percent lipids. In this regard it is chemically quite distinct from the more dominant textile, cotton, which is mainly cellulose.[1]

Characteristics

Champion hogget fleece, Walcha Show

Wool is produced by follicles which are small cells located in the skin. These follicles are located in the upper layer of the skin called the epidermis and push down into the second skin layer called the dermis as the wool fibers grow. Follicles can be classed as either primary or secondary follicles. Primary follicles produce three types of fiber: kemp, medullated fibers, and true wool fibers. Secondary follicles only produce true wool fibers. Medullated fibers share nearly identical characteristics to hair and are long but lack crimp and elasticity. Kemp fibers are very coarse and shed out.[2]

Fleece of fine New Zealand Merino wool and combed wool top on a wool table

Wool's scaling and crimp make it easier to spin the fleece by helping the individual fibers attach to each other, so they stay together. Because of the crimp, wool fabrics have greater bulk than other textiles, and they hold air, which causes the fabric to retain heat. Wool has a high specific thermal resistance, so it impedes heat transfer in general. This effect has benefited desert peoples, as Bedouins and Tuaregs use wool clothes for insulation.

Felting of wool occurs upon hammering or other mechanical agitation as the microscopic barbs on the surface of wool fibers hook together.

Wool has several qualities that distinguish it from hair/fur: it is crimped and elastic.[3]

The amount of crimp corresponds to the fineness of the wool fibers. A fine wool like Merino may have up to 100 crimps per inch, while coarser wool like karakul may have as few as one or two. In contrast, hair has little if any scale and no crimp, and little ability to bind into yarn. On sheep, the hair part of the fleece is called kemp. The relative amounts of kemp to wool vary from breed to breed and make some fleeces more desirable for spinning, felting, or carding into batts for quilts or other insulating products, including the famous tweed cloth of Scotland.

Wool fibers readily absorb moisture, but are not hollow. Wool can absorb almost one-third of its own weight in water.[4] Wool absorbs sound like many other fabrics. It is generally a creamy white color, although some breeds of sheep produce natural colors, such as black, brown, silver, and random mixes.

Wool ignites at a higher temperature than cotton and some synthetic fibers. It has a lower rate of flame spread, a lower rate of heat release, a lower heat of combustion, and does not melt or drip;[5] it forms a char which is insulating and self-extinguishing, and it contributes less to toxic gases and smoke than other flooring products when used in carpets.[6] Wool carpets are specified for high safety environments, such as trains and aircraft. Wool is usually specified for garments for firefighters, soldiers, and others in occupations where they are exposed to the likelihood of fire.[6]

Wool causes an allergic reaction in some people.[7]

Other Languages
Afrikaans: Wol
العربية: صوف
aragonés: Lana
armãneashti: Lânâ
asturianu: Llana
Aymar aru: T'arwa
azərbaycanca: Yun
беларуская: Воўна
беларуская (тарашкевіца)‎: Воўна
български: Вълна (влакна)
bosanski: Vuna
català: Llana
čeština: Ovčí vlna
corsu: Lana
Cymraeg: Gwlân
dansk: Uld
Deutsch: Wolle
Diné bizaad: Aghaaʼ
eesti: Vill
Ελληνικά: Μαλλί
español: Lana
Esperanto: Lano
euskara: Artile
فارسی: پشم
français: Laine
Frysk: Wol
Gaeilge: Olann
galego: La
ગુજરાતી: ઊન
한국어: 모섬유
հայերեն: Բուրդ
हिन्दी: ऊन
hrvatski: Vuna
Ido: Lano
Bahasa Indonesia: Wol
íslenska: Ull
italiano: Lana
עברית: צמר
Kabɩyɛ: Heu hʋndʋ
ಕನ್ನಡ: ಉಣ್ಣೆ
ქართული: მატყლი
Kreyòl ayisyen: Lenn
kurdî: Hirî
Кыргызча: Жүн
latviešu: Vilna
lietuvių: Vilna
Limburgs: Wöl
magyar: Gyapjú
македонски: Волна
മലയാളം: കമ്പിളി
मराठी: लोकर
Bahasa Melayu: Wul
монгол: Ноос
မြန်မာဘာသာ: သိုးမွေး
Nāhuatl: Ichcatohmitl
Nederlands: Wol
नेपाल भाषा: तँय्
日本語: ウール
norsk nynorsk: Ull
occitan: Lana (moton)
ਪੰਜਾਬੀ: ਉੱਨ
پنجابی: اُنّ
Plattdüütsch: Wull
polski: Wełna
português:
română: Lână
Runa Simi: Millma
Scots: Oo
shqip: Leshi
Simple English: Wool
سنڌي: اُنَ
slovenčina: Vlna (pokryv tela)
slovenščina: Volna
Soomaaliga: Dhogor
српски / srpski: Вуна
srpskohrvatski / српскохрватски: Vuna
Basa Sunda: Wol
suomi: Villa
svenska: Ull
Tagalog: Lana
தமிழ்: கம்பளி
తెలుగు: ఉన్ని
тоҷикӣ: Пашм
Türkçe: Yün
українська: Вовна
اردو: اون
Tiếng Việt: Len
West-Vlams: Wulle
ייִדיש: וואל
粵語: 羊毛
Zazaki: Peşm
中文: 羊毛