Cotton

Cotton fiber is a single plant cell that develops from the seed coat. The thickness of one fiber - 15-25 microns; Depending on the fiber length (from 5 to 60 mm), the yarn made from it is classified as short fiber, medium fiber and fine fiber and subjected to various processing. The fiber is a hollow tube (which explains the poor thermal conductivity ), curled around its axis (7-10 times per 1 mm). As the fiber matures, cellulose deposits grow, resulting in increased fiber strength. The chemical composition of 95% consists of cellulose, the remaining 5% - fat and mineral impurities ^{[2] [3]} .

Code symbol indicating cotton can be recycled

• It has a high hygroscopicity (ability to absorb moisture). Fiber swelling increases by about 40% by volume. Unlike other fabrics, when cotton is wet, strength does not decrease, but increases (by about 15%).
• In terms of strength, it is comparable to silk (if we compare the breaking load of natural fibers); inferior in strength to flax and surpasses wool .
• Like all natural fabrics, it is sensitive to light - after 940 hours of exposure to sunlight, durability decreases by half.
• More than silk , it is sensitive to prolonged exposure to high temperatures - after three days of heating to 150 ° C, the strength is halved.
• Thermoplastic - able to “memorize” the shape after heating (in other words, it can be ironed), which allows you to add cotton to suit fabrics made from synthetic fibers to improve properties.
• The recommended temperature of the wet-heat treatment is 130 ° C.
• Fabrics without processing are easily wrinkled and abraded; resistance to abrasion is solved by the addition of synthetic fabrics (capron); Increased crushing is eliminated after the so-called permanent rubber urea - formaldehyde or melamine-formaldehyde resin.
• Like other natural fibers, it does not dissolve in organic solvents (for example, in formic acid , vinegar , alcohol ), which makes it possible to use these readily available reagents for cleaning complex stains on cotton fabrics at home. However, it is sensitive to the action of inorganic acids and alkalis ; Alkali treatment (for example, caustic soda ) is used in fabric manufacture (see Mercerization ).
• Sensitive to the activity of microorganisms (in other words - rotting ).

When burning, cotton gives off a smell of burnt paper ^[4] .

The advantages of cotton fiber fabrics: low cost of production, good hygienic properties (in terms of hygroscopicity and breathability), the ability to shrink. Disadvantages: susceptibility to pilling, abrasion, crushability (without special treatment), sensitivity to light (like most natural fabrics), a large amount of irreversible deformations (stretching of the product) due to a small amount of elastic deformation.

Four species ( lat . Gossypium arboreum, Gossypium barbadense, Gossypium herbaceum, Cotton plant ) of the genus cotton began, most likely independently, to be used for the manufacture of textiles and cultivated in four regions of the Old and New Worlds ^[5] .

For the first time in the Old World, cotton began to be cultivated 7000 years ago ( 5th millennium BC ) by representatives of the civilization that was located in the Indus Valley . Evidence of the cultivation of cotton was found in archaeological studies of the Mergarkh culture , where copper beads with preserved cotton threads were found ^[6] . During the period of the Indian civilization , which occupied a huge area in the northwestern part of South Asia , where the territories of eastern Pakistan and northwestern India are now located, cotton became more widespread ^[7] . Cotton production in the Indus Valley was highly developed, and some of the methods used at that time for cotton spinning and processing continued to be used until the modern industrialization period of India ^[8] . Between 2000 and 1000 BC. er cotton has spread throughout almost all of India ^[9] . For example, it was found during excavations in Hallius, Karnataka ( 1000 BC ). The use of cotton textiles has spread from India to the Mediterranean and beyond.

Cotton goods were found in a cave near Tehuacán , Mexico, and are dated around 5800 BC. er , although the dating data is inaccurate due to the decomposition of the fibers ^[10] . Other sources include the cultivation of cotton in ancient Mexico around 5000 - 3000 BC. er ^[11] .

Cotton was unknown to the Greeks and Arabs until the wars of Alexander the Great . A contemporary of Alexander, the ancient Greek traveler Megasfen , told the commander Seleucus about the fact that "... there were trees on which the wool grows" (excerpt from " " Megasthen).

In Iran ( Persia ), the history of cotton goes back to the era of the Achaemenids ( V century BC ). However, sources relating to the cultivation of cotton in Iran before the advent of Islam there, have reached our days very little. Cotton cultivation was common in Merv , Rey , and in the Fars region. In the poems of Persian poets , especially in Shahnam Firdousi , one can find many references to cotton ( “panbe” in Persian . Marco Polo (XIII century), mentioning the main products of Persia, mentions cotton as well. Jean Chardin , XVII French traveler Century, who visited Persia Safavid , confirmed the existence of extensive cotton plantations there ^[12] .

During the Han Dynasty, the Chinese grew cotton in the territory of the current Yunnan province ^[13] .

In Peru, the cultivation of the local variety of Peruvian cotton - cotton ( ) became the basis for the development of coastal crops such as North-Chico , Moche , Nazca . Cotton was grown in the upper reaches of the rivers, and the nets made of it were then exchanged among the inhabitants of fishing coastal villages for impressive quantities of fish. The Spaniards , who arrived in Mexico and Peru at the beginning of the 16th century , found locals growing cotton and wearing clothes made from it.

At the end of the Middle Ages, cotton became known in northern Europe as an import item, without any idea how it was actually produced, it was only known that it was obtained from plants. Given its similarity with wool, people gave birth to the guesswork that cotton comes from sheep born from plants. John Mandeville , in his notes of 1350, affirms as a fact the now seemingly absurd belief: “There (in India ) an amazing tree grows, from the branches of which little sheep are born. These branches are so flexible that they lean down, giving the sheep the opportunity to feed when they are hungry ”(see also Baranets ). This belief was fixed in many European languages ​​in the word for "cotton", for example, in the German Baumwolle , which translates as "wood wool". By the end of the 16th century, cotton was cultivated everywhere in the warm regions of Asia and America .

Cotton production in India during the British conquest and the founding of British India in the late 18th and early 19th centuries declined steadily. Mostly this was due to the aggressive colonialist policies of the British East India Company , which pursues its own selfish ends, which made the processing and production of cotton goods by the local population uncompetitive. India was forced to supply only raw cotton and is obliged, through the introduction of special laws, to buy finished textiles in Britain .

The first tool for cleaning cotton from seeds in India was the so-called “chock”, consisting of two rollers, the upper one being fixed and the lower one rotated with the help of a handle. Cotton with seeds was fed between the rollers, the roller grabbed the fiber and dragged it to the other side, and the seeds that could not pass between the rollers, broke off and fell in front. In this operation, two or three shift workers could clean no more than 6-8 kg of pure cotton per day. Therefore, large and cheap cotton production was out of the question.

The Industrial Revolution in Britain

The onset of the industrial revolution in Britain led to the explosive development of the cotton industry, which made textiles the main export commodity of the British. In 1738, and from Birmingham , England, patented a spinning spinning machine and a roving frame system to produce a more uniform cotton surface. Later, the invention of a periodic spinning machine in 1764 and the invention of a spinning mechanism in 1769 by Richard Arkwright allowed the British weavers to produce yarn and clothing from cotton at a much faster pace. From the end of the 18th century, the English city of Manchester received the nickname “Cottonpolis” ( English Cottonopolis ), because the cotton industry is flooding the city and it becomes the center of world trade in products. The production capacity of Britain and the United States increased with the invention in 1793 by the American Eli Whitney of the first efficient cotton-gin cotton gin . Until that time, cotton fibers were extracted from the seeds by hand, which was extremely time-consuming. In order to produce a bale of cotton, more than 600 man-hours of labor were required ^[14] , which made the production of cotton in the United States on an industrial scale uneconomical, even with the condition of using slave labor. The invention of Whitney has reduced the time of production of cotton bale to approximately 12 hours.

Improved technology and increasing control over the world market allowed British traders to create a production chain in which raw cotton was purchased from colonial plantations, cotton fabric was created from Lancashire’s mills, which were then exported through the English fleet to controlled colonial markets in British West Africa , British India and China (to Shanghai and Hong Kong).

By 1840, India could no longer cope with the supply of a huge amount of cotton fiber required by the mechanized factories of Britain, while transporting large volumes of cheap cotton from the sea to India was very expensive and time consuming. For this reason, and also because American cotton had better characteristics (American cotton varieties, cotton and had longer and stronger fibers), British traders began to buy cotton from the plantations of the United States and the West Indies . By the middle of the XIX century, became the cornerstone of the economy of the southern states. In the US, growing and harvesting cotton plantations has become the main occupation of slaves.

During the American Civil War, cotton exports from the country almost ceased due to the blockade by the allies of the ports of the southerners , and also because the Confederates decided to stop exports, hoping that this would force the UK to recognize the Confederation or take part in the war. But the British and French instead began to buy Egyptian cotton. Significant investments were made in the development of cotton plantations, the Ismail Pasha government received substantial loans from European bankers and stock exchanges. Also at this time, cotton production in India increased again.

After the end of the Civil War and the publication of the Proclamation on the Emancipation of Slaves, cotton continued to remain the main agricultural crop of the South. There was a widespread use when free African-American and landless white farmers worked on rich plantations for a fraction of their income. The plantations required a large amount of labor due to the laboriousness of the manual cotton picking process until the 1950s, when cotton harvesters appeared. In general, since the beginning of the 20th century, the employment level in the cotton industry has declined due to the development of mechanization. Today, cotton remains the main export commodity in the south of the United States, and most of the annual cotton crop is American American long-staple cotton ^[15] .

Successful cultivation of cotton requires a long period of warm temperatures without frost, a sufficient number of sunny days and moderate rainfall, usually from 600 to 2000 mm. In general, suitable growth conditions are found in the tropical and subtropical zones of the northern and southern hemispheres in regions with long dry seasons. Most cotton today is grown using irrigation and irrigation systems. Landing time in the Northern Hemisphere can vary from February to early June. The area in the United States , known as the Southern Plains , is the largest continuous cotton growing region in the world. Water for irrigating cotton in this dry region is extracted from the Ogallala aquifer ( English Ogallala Aquifer ). Cotton's resistance to salts and drought makes it a convenient crop for arid regions . Due to the fact that there is currently a water problem on Earth, those economies that depend on cotton face serious difficulties and environmental problems ^{[16] [17] [18] [19] [20]} . For example, ill-conceived cultivation and irrigation have led to desertification of large areas in Uzbekistan , for which cotton is the main export commodity. The diversion of water for irrigation, including cotton fields, led to the tragedy of the Aral Sea ^{[19] [20]} .

Currently, cotton can be grown in such a way as to have not only the usual yellowish-white color, but also red, green and brown ( ) ^[21] .

It is estimated that 300-500 thousand people annually poison the cotton plantations in the world, 20 thousand of them die ^[22] .

When ripe, the cotton boll opens. The fiber, along with the unseparated seeds - raw cotton - is collected at cotton receiving points, from where it is sent to a cotton gin, where the fibers are separated from the seeds. This is followed by the separation of fibers along the length: the actual cotton fiber - fibers longer than 20 mm, fluff ( lint ) - less than 20 mm, and underfoot ( delint ) - less than 5 mm ^[23] .

Большинство хлопка в Соединённых Штатах, Европе и Австралии собирается механически либо хлопкоуборочной машиной , либо машиной, которая удаляет хлопок из коробочки, не повреждая хлопчатника, или хлопкосъёмником, который удаляет всю коробочку с растения. Хлопкосъёмники используются в регионах, где слишком ветрено, и обычно после нанесения химического дефолианта или естественной дефолиации, которая возникает при замораживании. Хлопок — это многолетнее растение в тропиках, и без дефолиации или замораживания растение будет продолжать расти.

В развивающихся странах хлопок продолжают собирать вручную ^[24] .

Хлопок идёт на текстильную обработку для получения хлопчатобумажной пряжи . Из хлопка вырабатывают ткани, трикотаж, нити, вату и другое. Пух и подпушек хлопка применяют в химической промышленности как сырьё для изготовления искусственного волокна и нитей, плёнки, лаков и т. п. ^[25] Его используют во взрывчатых веществах.

Начиная с 1998–1999 годов главным потребителем хлопка является текстильная промышленность Китая (около 35 % мирового потребления). Потребности в хлопке не компенсируются собственными ресурсами Китая, принуждая его к импорту сырья.

Крупнейшим экспортёром хлопка в период 2001–2005 годы являются США (чуть меньше 40 % всего экспорта), на втором месте — африканские страны « зоны франка » ( 9–13 % ).

В 2017 году мировой рынок хлопка-сырца оценивался в 13,2 млрд. долл. ^[26] . Главный экспортер - США, на него приходится почти 45% всего экспортируемого в 2017 году хлопка, далее следуют Индия 13%, Австралия 11%, Бразилия 10% и Греция 3%; замыкают десятку с показателем ок. 1%-1,5% Узбекистан, Буркина-Фасо, Камерун, Бенин и Туркменистан.

Главные импортеры: Китай 16%, Вьетнам 15%, Турция 12%, Бангладеш 12% и Индонезия 9,5%, Индия 6,9%, Пакистан 6,2%, Мексика 3,1%, Таиланд 2,9%, Южная Корея 2,8%

Средняя урожайность хлопка составляет 30 ц/га (3 т/га, или 300 т/км²). Максимальная — 50 ц/га (5 т/га, или 500 т/км²)

Хлопчатник изображён на гербах Узбекистана , Таджикистана , Туркменистана , Кыргызстана , Пакистана , Индонезии , Македонии , Анголы , Уганды и Сент-Винсента и Гренадин .

Также хлопок изображён на гербах некоторых регионов разных стран, городов и муниципалитетов, некоторых династий и организаций.

Органический хлопок ( англ. organic cotton ) — хлопок, выращенный из семян хлопчатника, не подвергавшихся генетической модификации , без химических удобрений , инсектицидов и пестицидов , то есть возделываемый по правилам « экологически чистого продукта » ^[27] .

По состоянию на 2007 год в наибольших количествах выращивался в Индии , Сирии , Турции , Китае и Перу . Всего плантации были в 24 странах (для сравнения, в 1992—1993 годы — лишь в 6 странах) ^[28] .

• Cotton fabrics // Brockhaus and Efron Encyclopedic Dictionary : 86 tons (82 tons and 4 extras). - SPb. , 1890-1907.
• Cotton // Brockhaus and Efron Encyclopedic Dictionary : 86 tons (82 tons and 4 extra). - SPb. , 1890-1907.

• Russian cotton community
• Cotton Odyssey - an article from No. 25/1999 of the Geography newspaper of the First September Publishing House.