Weaving is a method of textile production in which two distinct sets of yarns or threads are interlaced at right angles to form a fabric or cloth. Other methods are knitting, crocheting and braiding or plaiting; the longitudinal threads are called the warp and the lateral threads are the weft or filling. The method in which these threads are inter-woven affects the characteristics of the cloth. Cloth is woven on a loom, a device that holds the warp threads in place while filling threads are woven through them. A fabric band which meets this definition of cloth can be made using other methods, including tablet weaving, back strap loom, or other techniques without looms; the way the warp and filling threads interlace with each other is called the weave. The majority of woven products are created with one of three basic weaves: plain weave, satin weave, or twill. Woven cloth can be woven in decorative or artistic design. In general, weaving involves using a loom to interlace two sets of threads at right angles to each other: the warp which runs longitudinally and the weft that crosses it.
One warp thread is called. The warp threads are held taut and in parallel to each other in a loom. There are many types of looms. Weaving can be summarized as a repetition of these three actions called the primary motion of the loom. Shedding: where the warp threads are separated by raising or lowering heald frames to form a clear space where the pick can pass Picking: where the weft or pick is propelled across the loom by hand, an air-jet, a rapier or a shuttle. Beating-up or battening: where the weft is pushed up against the fell of the cloth by the reed; the warp is divided into two overlapping groups, or lines that run in two planes, one above another, so the shuttle can be passed between them in a straight motion. The upper group is lowered by the loom mechanism, the lower group is raised, allowing to pass the shuttle in the opposite direction in a straight motion. Repeating these actions form a fabric mesh but without beating-up, the final distance between the adjacent wefts would be irregular and far too large.
The secondary motion of the loom are the: Let off Motion: where the warp is let off the warp beam at a regulated speed to make the filling and of the required design Take up Motion: Takes up the woven fabric in a regulated manner so that the density of filling is maintainedThe tertiary motions of the loom are the stop motions: to stop the loom in the event of a thread break. The two main stop motions are the warp stop motion weft stop motionThe principal parts of a loom are the frame, the warp-beam or weavers beam, the cloth-roll, the heddles, their mounting, the reed; the warp-beam is a wooden or metal cylinder on the back of the loom. The threads of the warp extend in parallel order from the warp-beam to the front of the loom where they are attached to the cloth-roll; each thread or group of threads of the warp passes through an opening in a heddle. The warp threads are separated by the heddles into two or more groups, each controlled and automatically drawn up and down by the motion of the heddles.
In the case of small patterns the movement of the heddles is controlled by "cams" which move up the heddles by means of a frame called a harness. Where a complex design is required, the healds are raised by harness cords attached to a Jacquard machine; every time the harness moves up or down, an opening is made between the threads of warp, through which the pick is inserted. Traditionally the weft thread is inserted by a shuttle. On a conventional loom, the weft thread is carried on a pirn, in a shuttle that passes through the shed. A handloom weaver could propel the shuttle by throwing it from side to side with the aid of a picking stick; the "picking" on a power loom is done by hitting the shuttle from each side using an overpick or underpick mechanism controlled by cams 80–250 times a minute. When a pirn is depleted, it is ejected from the shuttle and replaced with the next pirn held in a battery attached to the loom. Multiple shuttle boxes allow more than one shuttle to be used; each can carry a different colour.
The rapier-type weaving machines do not have shuttles, they propel the weft by means of small grippers or rapiers that pick up the filling thread and carry it halfway across the loom where another rapier picks it up and pulls it the rest of the way. Some carry the filling yarns across the loom at rates in excess of 2,000 metres per minute. Manufacturers such as Picanol have reduced the mechanical adjustments to a minimum, control all the functions through a computer with a graphical user interface. Other types use compressed air to insert the pick, they are all fast and quiet. The warp is sized in a starch mixture for smoother running; the loom warped by passing the sized warp threads through two or more heddles attached to harnesses. The power weavers. Most looms used for industrial purposes have a machine that ties new warps threads to the waste of used warps threads, while still on the loom an operator rolls the old and new threads back on the warp beam; the harnesses are controlled by dobbies or a Jacquard head.
The raising and lowering
A camel is an even-toed ungulate in the genus Camelus that bears distinctive fatty deposits known as "humps" on its back. Camels have long been domesticated and, as livestock, they provide food and textiles; as working animals, camels—which are uniquely suited to their desert habitats—are a vital means of transport for passengers and cargo. There are three surviving species of camel; the one-humped dromedary makes up 94% of the world's camel population, the two-humped Bactrian camel makes up the remainder. The Wild Bactrian camel is now critically endangered; the word camel is derived via Latin: camelus and Greek: κάμηλος from Hebrew or Phoenician: gāmāl. Used informally, "camel" refers to any of the seven members of the family Camelidae: the dromedary, the Bactrian, the wild Bactrian, plus the llama, the alpaca, the guanaco, the vicuña; the dromedary known as the Arabian camel, inhabits the Middle East and the Horn of Africa, while the Bactrian inhabits Central Asia, including the historical region of Bactria.
The critically endangered wild Bactrian is found only in remote areas of northwest China and Mongolia. An extinct species of camel in the separate genus Camelops, known as C. hesternus, lived in western North America until humans entered the continent at the end of the Pleistocene. The average life expectancy of a camel is 40 to 50 years. A full-grown adult camel stands 1.85 m at 2.15 m at the hump. Camels can sustain speeds of up to 40 km/h. Bactrian camels dromedaries 300 to 600 kg; the widening toes on a camel's hoof provide supplemental grip for varying soil sediments. The male dromedary camel has an organ called a dulla in its throat, a large, inflatable sac he extrudes from his mouth when in rut to assert dominance and attract females, it resembles a long, pink tongue hanging out of the side of its mouth. Camels mate by having both male and female sitting on the ground, with the male mounting from behind; the male ejaculates three or four times within a single mating session. Camelids are the only ungulates to mate in a sitting position.
Camels do not directly store water in their humps. Concentrating body fat in their humps minimizes the insulating effect fat would have if distributed over the rest of their bodies, helping camels survive in hot climates; when this tissue is metabolized, it yields more than one gram of water for every gram of fat processed. This fat metabolization, while releasing energy, causes water to evaporate from the lungs during respiration: overall, there is a net decrease in water. Camels have a series of physiological adaptations that allow them to withstand long periods of time without any external source of water; the dromedary camel can drink as as once every 10 days under hot conditions, can lose up to 30% of its body mass due to dehydration. Unlike other mammals, camels' red blood cells are oval rather than circular in shape; this facilitates the flow of red blood cells during dehydration and makes them better at withstanding high osmotic variation without rupturing when drinking large amounts of water: a 600 kg camel can drink 200 L of water in three minutes.
Camels are able to withstand changes in body temperature and water consumption that would kill most other animals. Their temperature ranges from 34 °C at dawn and increases to 40 °C by sunset, before they cool off at night again. In general, to compare between camels and the other livestock, camels lose only 1.3 liters of fluid intake every day while the other livestock lose 20 to 40 liters per day. Maintaining the brain temperature within certain limits is critical for animals. Camels sweat when ambient temperatures reach 49 °C. Any sweat that does occur evaporates at the skin level rather than at the surface of their coat. Camels can withstand losing 25% of their body weight to sweating, whereas most other mammals can withstand only about 12–14% dehydration before cardiac failure results from circulatory disturbance; when the camel exhales, water vapor becomes trapped in their nostrils and is reabsorbed into the body as a means to conserve water. Camels eating green herbage can ingest sufficient moisture in milder conditions to maintain their bodies' hydrated state without the need for drinking.
The camels' thick coats insulate them from the intense heat radiated from desert sand. During the summer the coat becomes lighter in color, reflecting light as well as helping avoid sunburn; the camel's long legs help by keeping its body farther from the ground, which can heat up to 70 °C. Dromedaries have a pad of thick tissue over the sternum called the pedestal; when the animal lies down in a sternal recumbent position, the pedestal raises the body from the hot surface and allows cooling air to pass under the body. Camels' mouths have a thick leathery lining. Long eyelashes and ear hairs, together with nostrils, form a barrier against sand. If sand gets lodged in their eyes, they can dislodge it using their transparent t
A rope is a group of yarns, fibers or strands that are twisted or braided together into a larger and stronger form. Ropes so can be used for dragging and lifting. Rope is thicker and stronger than constructed cord and twine. Rope may be constructed of any long, fibrous material, but is constructed of certain natural or synthetic fibres. Synthetic fibre ropes are stronger than their natural fibre counterparts, they have a higher tensile strength, they are more resistant to rotting than ropes created from natural fibers, can be made to float on water, but synthetic rope possess certain disadvantages, including slipperiness, some can be damaged more by UV light. Common natural fibres for rope are manila hemp, linen, coir, jute and sisal. Synthetic fibres in use for rope-making include polypropylene, polyesters, polyethylene and acrylics; some ropes are constructed of mixtures of several fibres or use co-polymer fibres. Wire rope is made of steel or other metal alloys. Ropes have been constructed of other fibrous materials such as silk and hair, but such ropes are not available.
Rayon is a regenerated fibre used to make decorative rope. The twist of the strands in a twisted or braided rope serves not only to keep a rope together, but enables the rope to more evenly distribute tension among the individual strands. Without any twist in the rope, the shortest strand would always be supporting a much higher proportion of the total load; the long history of rope means. In systems that use the "inch", large ropes over 1 inch diameter such as are used on ships are measured by their circumference in inches. In metric systems of measurement, nominal diameter is given in millimetres; the current preferred international standard for rope sizes is to give the mass per unit length, in kilograms per metre. However sources otherwise using metric units may still give a "rope number" for large ropes, the circumference in inches. Rope is of paramount importance in fields as diverse as construction, exploration, sports and communications, has been used since prehistoric times. To fasten rope, many types of knots have been invented for countless uses.
Pulleys redirect the pulling force to another direction, can create mechanical advantage so that multiple strands of rope share a load and multiply the force applied to the end. Winches and capstans are machines designed to pull ropes; the modern sport of rock climbing uses so-called "dynamic" rope, which stretches under load in an elastic manner to absorb the energy required to arrest a person in free fall without generating forces high enough to injure them. Such ropes use a kernmantle construction, as described below. "Static" ropes, used for example in caving and rescue applications, are designed for minimal stretch. The UIAA, in concert with the CEN, oversees testing. Any rope bearing a GUIANA or CE certification tag is suitable for climbing. Despite the hundreds of thousands of falls climbers suffer every year, there are few recorded instances of a climbing rope breaking in a fall. Climbing ropes, however, do cut when under load. Keeping them away from sharp rock edges is imperative. Rock climbing ropes come with either a designation for double or twin use.
A single rope is the most common and it is intended to be used by itself, as a single strand. Single ropes range in thickness from 9 mm to 11 mm. Smaller ropes wear out faster. Double ropes are thinner ropes 9 mm and under, are intended for use as a pair; these ropes offer a greater margin or security against cutting, since it is unlikely that both ropes will be cut, but they complicate belaying and leading. Double ropes are reserved for ice and mixed climbing, where there is need for two ropes to rappel or abseil, they are popular among traditional climbers, in the UK, due to the ability to clip each rope into alternating pieces of protection. Twin ropes are not to be confused with doubles; when using twin ropes, both ropes are clipped into the same piece of protection, treating the two as a single strand. This would be favourable in a situation; however new lighter-weight ropes with greater safety have replaced this type of rope. The butterfly coil is a method of carrying a rope used by climbers where the rope remains attached to the climber and ready to be uncoiled at short notice.
Another method of carrying a rope is the alpine coil. Rope is an aerial acrobatics circus skill, where a performer makes artistic figures on a vertical suspended rope. Tricks performed on the rope are, for example, drops and hangs, they must be strong. See Corde lisse; the use of ropes for hunting, fastening, carrying and climbing dates back to prehistoric times. It is that the earliest "ropes" were occurring lengths of plant fibre, such as vines, followed soon by the first attempts at twisting and braiding these strands together to form the first proper ropes in the modern sense of the word. Impressions of cordage found on fired
Crochet is a process of creating fabric by interlocking loops of yarn, thread, or strands of other materials using a crochet hook. The name is derived from the French term crochet, meaning'small hook'; these are made of materials such as metal, wood, or plastic and are manufactured commercially and produced in artisan workshops. The salient difference between crochet and knitting, beyond the implements used for their production, is that each stitch in crochet is completed before the next one is begun, while knitting keeps a large number of stitches open at a time; the word crochet is derived from the Old French crochet, a diminutive of croche, in turn from the Germanic croc, both meaning "hook". It was used in 17th-century French lace making, crochetage designating a stitch used to join separate pieces of lace, crochet subsequently designating both a specific type of fabric and the hooked needle used to produce it. Although the fabric is not known to be crochet in the present sense, a genealogical relationship between the techniques sharing that name appears likely.
Knitted textiles survive from early periods, but the first substantive evidence of crocheted fabric relates to its appearance in Europe during the 19th century. Earlier work identified as crochet was made by nålebinding, a different looped yarn technique; the first known published instructions for crochet explicitly using that term to designate the craft in its present sense appeared in the Dutch magazine Penélopé in 1823. This includes a color plate showing five styles of purse of which three were intended to be crocheted with silk thread; the first is "simple open crochet". The second starts in a semi-open form, where chain-stitch arches alternate with long segments of slip-stitch crochet, closes with a star made with "double-crochet stitches"; the third purse is made in double-crochet. The instructions prescribe the use of a tambour needle and introduce a number of decorative techniques; the earliest dated English reference to garments made of cloth produced by looping yarn with a hook—shepherd's knitting—is in The Memoirs of a Highland Lady by Elizabeth Grant.
The journal entry, itself, is dated 1812 but was not recorded in its subsequently published form until some time between 1845 and 1867, the actual date of publication was first in 1898. Nonetheless, the 1833 volume of Penélopé describes and illustrates a shepherd's hook, recommends its use for crochet with coarser yarn. In 1842, one of the numerous books discussing crochet that began to appear in the 1840s states: "Crochet needles, sometimes called Shepherds' hooks, are made of steel, ivory, or box-wood, they have a hook at one end similar in shape to a fish-hook, by which the wool or silk is caught and drawn through the work. These instruments are to be procured of various sizes..."Two years the same author, writes: "Crochet, — a species of knitting practised by the peasants in Scotland, with a small hooked needle called a shepherd’s hook, — has, within the last seven years, aided by taste and fashion, obtained the preference over all other ornamental works of a similar nature. It derives its present name from the French.
This art has attained its highest degree of perfection in England, whence it has been transplanted to France and Germany, both countries, although unjustifiably, have claimed the invention."An instruction book from 1846 describes Shepherd or Single Crochet as what in current British usage is either called single crochet or slip-stitch crochet, with U. S. American terminology always using the latter, it equates "Double" and "French crochet". Notwithstanding the categorical assertion of a purely British origin, there is solid evidence of a connection between French tambour embroidery and crochet; the former method of production was illustrated in detail in 1763 in Diderot's Encyclopedia. The tip of the needle shown there is indistinguishable from that of a present-day inline crochet hook and the chain stitch separated from a cloth support is a fundamental element of the latter technique; the 1823 Penélopé instructions unequivocally state that the tambour tool was used for crochet and the first of the 1840s instruction books uses the terms tambour and crochet as synonyms.
This equivalence is retained in the 4th edition of that work, 1847. The strong taper of the shepherd's hook eases the production of slip-stitch crochet but is less amenable to stitches that require multiple loops on the hook at the same time. Early yarn hooks were continuously tapered but enough to accommodate multiple loops; the design with a cylindrical shaft, commonplace today was reserved for tambour-style steel needles. Both types merged into the modern form that appeared toward the end of the 19th century, including both tapered and cylindrical segments, the continuously tapered bone hook remained in industrial production until World War II; the early instruction books make frequent reference to the alternative use of'ivory, bone, or wooden hooks' and'steel needles in a handle', as appropriate to the stitch being made. Taken with the synonymous labeling of shepherd's- and single crochet, the similar equivalence of French- and double crochet, there is a strong suggestion that crochet is rooted both in tambour embroidery and shepherd's knitting, leading to thread and yarn crochet
A textile is a flexible material consisting of a network of natural or artificial fibers. Yarn is produced by spinning raw fibres of wool, cotton, hemp, or other materials to produce long strands. Textiles are formed by weaving, crocheting, knotting or tatting, felting, or braiding; the related words "fabric" and "cloth" and "material" are used in textile assembly trades as synonyms for textile. However, there are subtle differences in these terms in specialized usage. A textile is any material made of interlacing fibres, including carpeting and geotextiles. A fabric is a material made through weaving, spreading, crocheting, or bonding that may be used in production of further goods. Cloth may be used synonymously with fabric but is a piece of fabric, processed; the word'textile' is from Latin, from the adjective textilis, meaning'woven', from textus, the past participle of the verb texere,'to weave'. The word'fabric' derives from Latin, most from the Middle French fabrique, or'building, thing made', earlier as the Latin fabrica'workshop.
The word'cloth' derives from the Old English clað, meaning a cloth, woven or felted material to wrap around one, from Proto-Germanic kalithaz. The first clothes, worn at least 70,000 years ago and much earlier, were made of animal skins and helped protect early humans from the ice ages. At some point people learned to weave plant fibers into textiles; the discovery of dyed flax fibres in a cave in the Republic of Georgia dated to 34,000 BCE suggests textile-like materials were made in prehistoric times. The production of textiles is a craft whose speed and scale of production has been altered beyond recognition by industrialization and the introduction of modern manufacturing techniques. However, for the main types of textiles, plain weave, twill, or satin weave, there is little difference between the ancient and modern methods. Textiles have an assortment of uses, the most common of which are for clothing and for containers such as bags and baskets. In the household they are used in carpeting, upholstered furnishings, window shades, coverings for tables and other flat surfaces, in art.
In the workplace they are used in scientific processes such as filtering. Miscellaneous uses include flags, tents, handkerchiefs, cleaning rags, transportation devices such as balloons, kites and parachutes. Textiles are used in many traditional crafts such as sewing and embroidery. Textiles for industrial purposes, chosen for characteristics other than their appearance, are referred to as technical textiles. Technical textiles include textile structures for automotive applications, medical textiles, agrotextiles, protective clothing. In all these applications stringent performance requirements must be met. Woven of threads coated with zinc oxide nanowires, laboratory fabric has been shown capable of "self-powering nanosystems" using vibrations created by everyday actions like wind or body movements. Textiles are made from many materials, with four main sources: animal, plant and synthetic; the first three are natural. In the 20th century, they were supplemented by artificial fibres made from petroleum.
Textiles are made in various strengths and degrees of durability, from the finest microfibre made of strands thinner than one denier to the sturdiest canvas. Textile manufacturing terminology has a wealth of descriptive terms, from light gauze-like gossamer to heavy grosgrain cloth and beyond. Animal textiles are made from hair, skin or silk. Wool refers to the hair of the domestic sheep or goat, distinguished from other types of animal hair in that the individual strands are coated with scales and crimped, the wool as a whole is coated with a wax mixture known as lanolin, waterproof and dirtproof. Woollen refers to a bulkier yarn produced from carded, non-parallel fibre, while worsted refers to a finer yarn spun from longer fibres which have been combed to be parallel. Wool is used for warm clothing. Cashmere, the hair of the Indian cashmere goat, mohair, the hair of the North African angora goat, are types of wool known for their softness. Other animal textiles which are made from hair or fur are alpaca wool, vicuña wool, llama wool, camel hair used in the production of coats, ponchos and other warm coverings.
Angora refers to the long, soft hair of the angora rabbit. Qiviut is the fine inner wool of the muskox. Wadmal is a coarse cloth made of wool, produced in Scandinavia 1000~1500 CE. Sea silk is an fine and valuable fabric, made from the silky filaments or byssus secreted by a gland in the foot of pen shells. Silk is an animal textile made from the fibres of the cocoon of the Chinese silkworm, spun into a smooth fabric prized for its softness. There are two main ty
A cotton gin is a machine that and separates cotton fibers from their seeds, enabling much greater productivity than manual cotton separation. The fibers are processed into various cotton goods such as linens, while any undamaged cotton is used for textiles like clothing; the separated seeds may be used to produce cottonseed oil. Handheld roller gins had been used in the Indian subcontinent since at earliest AD 500 and in other regions; the Indian worm-gear roller gin, invented sometime around the 16th century, according to Lakwete, remained unchanged up to the present time. A modern mechanical cotton gin was created by American inventor Eli Whitney in 1793 and patented in 1794. Whitney's gin used a combination of a wire screen and small wire hooks to pull the cotton through, while brushes continuously removed the loose cotton lint to prevent jams, it revolutionized the cotton industry in the United States, but led to the growth of slavery in the American South as the demand for cotton workers increased.
The invention has thus been identified as an inadvertent contributing factor to the outbreak of the American Civil War. Modern automated cotton gins use multiple powered cleaning cylinders and saws, offer far higher productivity than their hand-powered precursors. Eli Whitney invented his cotton gin in 1793, he began to work on this project after moving to Georgia in search of work. Given that farmers were searching for a way to make cotton farming profitable, a woman named Catharine Greene provided Whitney with funding to create the first cotton gin. Whitney created two cotton gins: a small one that could be hand-cranked and a large one that could be driven by a horse or water power. A single-roller cotton gin came into use in India by the 5th century. An improvement invented in India was the two-roller gin, known as the "churka", "charki", or "wooden-worm-worked roller". Cotton fibers are produced in the seed pods of the cotton plant where the fibers in the bolls are interwoven with seeds. To make the fibers usable, the seeds and fibers must first be separated, a task, performed manually, with production of cotton requiring hours of labor for the separation.
Many simple seed-removing devices had been invented, but until the innovation of the cotton gin, most required significant operator attention and worked only on a small scale. The earliest versions of the cotton gin consisted of a single roller made of iron or wood and a flat piece of stone or wood. Evidence for this type of gin has been found in Africa and North America; the first documentation of the cotton gin by contemporary scholars is found in the fifth century AD, in the form of Buddhist paintings depicting a single-roller gin in the Ajanta Caves in western India. These early gins required a great deal of skill. A narrow single roller was necessary to expel the seeds from the cotton without crushing the seeds; the design was similar to that of a mealing stone, used to grind grain. The early history of the cotton gin is ambiguous, because archeologists mistook the cotton gin's parts for other tools. Between the 12th and 14th centuries, dual-roller gins appeared in China; the Indian version of the dual-roller gin was prevalent throughout the Mediterranean cotton trade by the 16th century.
This mechanical device was, in some areas, driven by water power. The worm gear roller gin, invented in the Indian subcontinent during the early Delhi Sultanate era of the 13th to 14th centuries, came into use in the Mughal Empire sometime around the 16th century, is still used in the Indian subcontinent through to the present day. Another innovation, the incorporation of the crank handle in the cotton gin, first appeared sometime during the late Delhi Sultanate or the early Mughal Empire; the incorporation of the worm gear and crank handle into the roller cotton gin led to expanded Indian cotton textile production during the Mughal era. It was reported that, with an Indian cotton gin, half machine and half tool, one man and one woman could clean 28 pounds of cotton per day. With a modified Forbes version, one man and a boy could produce 250 pounds per day. If oxen were used to power 16 of these machines, a few people's labour was used to feed them, they could produce as much work as 750 people did formerly.
The Indian roller cotton gin, known as the churka or charkha, was introduced to the United States in the mid-18th century, when it was adopted in the southern United States. The device was adopted for cleaning long-staple cotton, but was not suitable for the short-staple cotton, more common in certain states such as Georgia. Several modifications were made to the Indian roller gin by Mr. Krebs in 1772 and Joseph Eve in 1788, but their uses remained limited to the long-staple variety, up until Eli Whitney's development of a short-staple cotton gin in 1793. Eli Whitney applied for a patent of his cotton gin on October 28, 1793. Whitney's patent was assigned patent number 72X. There is slight controversy over whether the idea of the modern cotton gin and its constituent elements are attributed to Eli Whitney; the popular image of Whitney inventing the cotton gin is attributed to an article on the subject written in the early 1870s and reprinted in 1910 in The Library of Southern Literature. In this article, the author claimed Catharine Littlefield Greene suggested to Whitney the use of a brush-like component instrumental in separating out the seeds and cotton.
To date, Greene's role in the invention of the gin has not been verified independently. Whitney's cotton gin model was capable of clea
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, other types of wool from camelids. Wool consists of protein together with a few percent lipids. In this regard it is chemically quite distinct from the more dominant textile, cellulose. Wool is produced by follicles; 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 secondary follicles. Primary follicles produce three types of fiber: kemp, medullated fibers, 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 coarse and shed out. 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, 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 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; 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, 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 absorb moisture, but are not hollow. Wool can absorb one-third of its own weight in water. Wool absorbs sound like many other fabrics, it is a creamy white color, although some breeds of sheep produce natural colors, such as black, brown and random mixes. Wool ignites at a higher temperature than some synthetic fibers, it has a lower rate of flame spread, a lower rate of heat release, a lower heat of combustion, does not melt or drip. Wool carpets are specified for high safety environments, such as trains and aircraft. Wool is specified for garments for firefighters and others in occupations where they are exposed to the likelihood of fire. Wool causes an allergic reaction in some people. Sheep shearing is the process. After shearing, the wool is separated into four main categories: fleece, broken and locks; the quality of fleeces is determined by a technique known as wool classing, whereby a qualified person, called a wool classer, groups wools of similar gradings together to maximize the return for the farmer or sheep owner.
In Australia before being auctioned, all Merino fleece wool is objectively measured for micron, staple length, staple strength, sometimes color and comfort factor. Wool straight off a sheep, known as "greasy wool" or "wool in the grease", contains a high level of valuable lanolin, as well as the sheep's dead skin and sweat residue, also contains pesticides and vegetable matter from the animal's environment. Before the wool can be used for commercial purposes, it must be scoured, a process of cleaning the greasy wool. Scouring may be as simple as a bath in warm water or as complicated as an industrial process using detergent and alkali in specialized equipment. In north west England, special potash pits were constructed to produce potash used in the manufacture of a soft soap for scouring locally produced white wool. In commercial wool, vegetable matter is removed by chemical carbonization. In less-processed wools, vegetable matter may be removed by hand and some of the lanolin left intact through the use of gentler detergents.
This semigrease wool can be worked into yarn and knitted into water-resistant mittens or sweaters, such as those of the Aran Island fishermen. Lanolin removed from wool is used in cosmetic products, such as hand creams. Raw wool has many impurities; the sheep's body yields many types of wool with differing strengths, length of staple and impurities. The raw wool is processed into'top'.'Worsted top' requires strong straight and parallel fibres. The quality of wool is determined by its fiber diameter, yield and staple strength. Fiber diameter is the single most important wool characteristic determining price. Merino wool is 3–5 inches in length and is fine; the finest and most valuable wool comes from Merino hoggets. Wool taken from sheep produced for meat is more coarse, has fibers 1.5 to 6 in in length. Damage or breaks in the wool can occur if the sheep is stressed whil