Textile Manufacture Production Operation Unite: 15
Research and demonstrate a broad understanding of the geographic, historic and economic significance of fibre production
Investigate and analyse information from a wide range of sources.
Fibre is a class of materials that are continuous filaments or are in discrete elongated pieces, similar to lengths of thread. They are very important in the biology of both plants and animals, for holding tissues together.
Synthetic fibers can often be produced very cheaply and in large amounts compared to natural fibers, but for clothing, natural fibers can give some benefits, such as comfort, over their synthetic counterparts.
Natural fibers include those produced by plants, animals, and geological processes. They are biodegradable over time. They can be classified according to their origin:
Vegetable fibers are generally based on arrangements of cellulose, often with lignin: examples include cotton, hemp, jute, flax, ramie, and sisal. Plant fibers are employed in the manufacture of paper and textile (cloth), and dietary fiber is an important component of human nutrition. Wood fiber, distinguished from vegetable fiber, is from tree sources. Forms include ground wood, thermo mechanical pulp (TMP) and bleached or unbleached Kraft or sulfite pulps. Kraft and sulfite, also called sulphite, refer to the type of pulping process used to remove the lignin bonding the original wood structure, thus freeing the fibers for use in paper and engineered wood products such as fiberboard.
Animal fibers consist largely of particular proteins. Instances are spider silk, sinew, catgut, wool and hair such as cashmere, mohair and angora, fur such as sheepskin, rabbit, mink, fox, beaver, etc.
Mineral fibers include the asbestos group. Asbestos is the only naturally occurring long mineral fiber. Six minerals have been classified as “asbestos” including Christie of the serpentine class and those belonging to the amphibole class: amosite, crocidolite, tremolite, anthophyllite and actinolite. Short, fiber-like minerals include wollastonite and attapulgite.
Cellulose fibers are a subset of man-made fibers, regenerated from natural cellulose. The cellulose comes from various sources. Modal is made from beech trees, bamboo fiber is a cellulose fiber made from bamboo, seacell is made from seaweed, etc. Bagasse is cellulose fiber made from sugarcane.
Mineral fibers can be particular strong because they are formed with a low number of surface defects. Fiberglass, made from specific glass, and optical fiber, made from purified natural quartz, are also man-made fibers that come from natural raw materials, silica fiber, made from sodium silicate (water glass) and basalt fiber made from melted basalt.
Metallic fibers can be drawn from ductile metals such as copper, gold or silver and extruded or deposited from more brittle ones, such as nickel, aluminum or iron. Silicon carbide fibers, where the basic polymers are not hydrocarbons but polymers, where about 50% of the carbon atoms are replaced by silicon atoms, so-called poly-carbo-silanes. The pyrolysis yields an amorphous silicon carbide, including mostly other elements like oxygen, titanium, or aluminium, but with mechanical properties very similar to those of carbon fibers.
Stainless steel fibers, Polymer fibers are a subset of man-made fibers, which are based on synthetic chemicals (often from petrochemical sources) rather than arising from natural materials by a purely physical process.
Coextruded fibers have two distinct polymers forming the fiber, usually as a core-sheath or side-by-side. Coated fibers exist such as nickel-coated to provide static elimination, silver-coated to provide anti-bacterial properties and aluminum-coated to provide RF deflection for radar chaff. Radar chaff is actually a spool of continuous glass tow that has been aluminum coated. An aircraft-mounted high speed cutter chops it up as it spews from a moving aircraft to confuse radar signals.
Global Distribution of Fibre:
The Global Organic Textile Standard (GOTS) is the worldwide leading textile processing standard for organic fibres, including ecological and social criteria, backed up by independent certification of the entire textile supply chain. The key criteria for fibre production can be identified as:
A textile product carrying the GOTS label grade ‘organic’ must contain a minimum of 95% certified organic fibres whereas a product with the label grade ‘made with organic’ must contain a minimum of 70% certified organic fibres.
- Discharge printing methods using aromatic solvents and plastisol printing methods using phthalates and PVC are prohibited.
- Wet processing units must keep full records of the use of chemicals, energy, water consumption and wastewater treatment, including the disposal of sludge. The wastewater from all wet processing units must be treated in a functional wastewater treatment plant.
- Packaging material must not contain PVC. From 1st January 2014 onwards any paper or cardboard used in packaging material, hang tags, swing tags etc.
Processing and Manufacturing
(Under Labor and Economic Transaction)
All processors and manufacturers must meet minimum social criteria based on the key norms of the International Labor Organization (ILO). They must have a social compliance management with defined elements in place to ensure that the social criteria can be met. For adequate implementation and assessment of the following social criteria topics the listed applicable key conventions of the International Labor Organization (ILO) have to be taken as the relevant basis for interpretation.
Quality Assurance isgenerally a company participating in the GOTS certification scheme must work in compliance with all criteria of the standard. GOTS relies on a dual system to check compliance with the relevant criteria consisting of on-site auditing and residue testing.
Certification of the entire textile supply chain Fibre producers (farmers) must be certified according to a recognized international or national organic farming standard that is accepted in the country where the final product will be sold: They also must be accredited to certify according to the applicable fibre standard.
Describe the production of a specific fibre or type of fabric using both historical and contemporary references
Cotton is the backbone of the world’s textile trade. Many of our everyday textile fabrics are made from cotton. So it is called ‘the king of the textile raw materials’. Like the other plant fibres, cotton is essentially cellulose. But the plant as part of its skeleton structure does not produce it, as are the best and leaf fibres. The fibre serves probably to accumulate moisture for germination of the seed.
History of cotton
No one knows exactly how old cotton is. Scientists searching caves in Mexico found bits of cotton bolls and pieces of cotton cloth that proved to be at least 7,000 years old. They also found that the cotton itself was much like that grown in America today. In the Indus River Valley in Pakistan, cotton was being grown, spun and woven into cloth 3,000 years BC. At about the same time, natives of Egypt’s Nile valley were making and wearing cotton clothing.Arab merchants brought cotton cloth to Europe about 800 A.D. When Columbus discovered America in 1492, he found cotton growing in the Bahamas Islands. By 1500, cotton was known generally throughout the world.Cotton seed are believed to have been planted in Florida in 1556 and in Virginia in 1607. By 1616, colonists were growing cotton along the James River in Virginia.Cotton was first spun by machinery in England in 1730. The industrial revolution in England and the invention of the cotton gin in the U.S. paved the way for the important place cotton holds in the world today. Eli Whitney, a native of Massachusetts, secured a patent on the cotton gin in 1793, though patent office records indicate that a machinist named Noah Homes two years before Whitney’s patent was filed may have built the first cotton gin. The gin, short for engine, could do the work 10 times faster than by hand.
The gin made it possible to supply large quantities of cotton fiber to the fast-growing textile industry. Within 10 years, the value of the U.S. cotton crop rose from $150,000 to more than $8 million.
The history of the domestication of cotton is very complex and is not known exactly. Several isolated civilizations independently domesticated and converted cotton into fabric. All the same tools were invented, including combs, bows, hand spindles, and primitive looms. The oldest cotton textiles were found in graves and city ruins of civilizations from dry climates, where the fabrics did not decay completely. Some of the oldest cotton bolls were discovered in a cave in Tehuacán Valley, Mexico, and were dated to approximately 5500 BCE, but estimates that are more recent have put the age of these bolls at approximately 3600 BCE. Seeds and cordage dating to about 4500 BCE have been found in Peru. The Indus Valley civilization spun cotton since at least 3500 BCE, as indicated by the ruins of Mohenjo-daro. Around the same time, cotton was being grown and processed in China, Mexico, and Arizona. Pre-Incan cotton grave cloths were found in Huaca Prieta in Peru, and date back to 2500 BCE, and cotton was mentioned in Hindu hymns in 1500 BCE.
Herodotus, an ancient Greek historian, mentions Indian cotton in the 5th century BCE as “a wool exceeding in beauty and goodness that of sheep.” When Alexander the Great invaded India, his troops started wearing cotton clothes that were more comfortable than their previous woolen ones. Strabo, another Greek historian, mentioned the vividness of Indian fabrics, and Arrian told of Indian–Arab trade of cotton fabrics in 130 CE. Egyptians grew and spun cotton from 6–700 CE.
In the 8th century, the Muslim conquest of Spain expanded the European cotton trade. By the 15th century, Venice, Antwerp, and Haarlem were important ports for cotton trade, and the sale and transportation of cotton fabrics had become very profitable.
Distribution of the world cotton fibre production, according to a 2007
Textile mills have moved from Western Europe to, more recently, lower-wage areas. Industrial production is currently mostly located in countries like India, Bangladesh, China, and in Latin America. In these regions labour is much less expensive than in the first world, and attracts poor workers.<href=”#cite_note-Newint-7> Biotechnology plays an important role in cotton agriculture as genetically modified cotton that can resist Roundup, a herbicide made by the company Monsanto, as well as repel insects.<href=”#cite_note-Cotton-1>:277 Organically grown cotton is becoming less prevalent in favour of synthetic fibres made from petroleum products. The demand for cotton has doubled since the 1980s. The main producer of cotton fibre is now China, at 24%, past the United States at 19% and India at 13%. In 2005/2006, China manufactured 7.15 million tons of textiles, more than double that of India at 3.1 million tons. The leading cotton exporter is the United States, whose production continues to increase due to government subsidies, estimated at $14 billion between 1995 and 2003. The value of cotton lint has been decreasing for sixty years, and the value of cotton has decreased by 50% in 1997–2007. The global textile andclothing industry employs 23.6 million workers, of which 75% are women.
Geographic and production of cotton
? Top ten cotton producer contry -2009.
(480 pound / bales)
|1||) People’s Republic of China||32.0 million bales|
|2||India||23.5 million bales.|
|3||United state||– 12.4 million bales|
|4||) Pakistan||– 9.8 million bales|
|5||Brazil||– 5.5 million bales|
|6||Uzbekistan||– 4.4 million bales|
|7||Australia||– 1.8 million bales|
|8||) Turkey||– 1.7 million bales|
|9||Turkmenistan||– 1.1 million bales|
|10||) Syria||1.0 million bales|
China is the 1st country to produce cotton in huge amount.
They sold the cotton bales to other countries and earned a huge of amount.
History of Silk
Sericulture or silk production has a long and colorful history unknown to most people. For centuries, the West knew very little about silk and the people who made it. Pliny, the Roman historian, wrote in his Natural History in 70 BC “Silk was obtained by removing the down from the leaves with the help of water…”. For more than two thousand years the Chinese kept the secret of silk altogether to themselves. It was the most zealously guarded secret in history.
History of silk (china):
Silk fabric was first developed in ancient China, with some of the earliest examples found as early as 3500 BC.Legend gives credit for developing silk to a Chinese empress, Leizu (Hsi-Ling-Shih, Lei-Tzu). Silks were originally reserved for the Kings of China for their own use and gifts to others, but spread gradually through Chinese culture and trade both geographically and socially, and then to many regions of Asia. Silk rapidly became a popular luxury fabric in the many areas accessible to Chinese merchants because of its texture and luster. Silk was in great demand, and became a staple of pre-industrial international trade. In July 2007, archeologists discovered intricately woven and dyed silk textiles in a tomb in Jiangxi province, dated to the Eastern Zhou Dynasty roughly 2,500 years ago. Although historians have suspected a long history of a formative textile industry in ancient China, this find of silk textiles employing “complicated techniques” of weaving and dyeing provides direct and concrete evidence for silks dating before the Mawangdui-discovery and other silks dating to the Han Dynasty (202 BC-220 AD).
The first evidence of the silk trade is the finding of silk in the hair of an Egyptian mummy of the 21st dynasty, c.1070 BC. Ultimately, the silk trade reached as far as the Indian subcontinent, the Middle East, Europe, and North Africa. This trade was so extensive that the major set of trade routes between Europe and Asia has become known as the Silk Road. The highest development was in China.
The Emperors of China strove to keep knowledge of sericulture secret to maintain the Chinese monopoly. Nonetheless sericulture reached Korea around 200 BC, about the first half of the 1st century AD had reached ancient Khotan,<href=”#cite_note-9> and by AD 140 the practice had been established in India.
In the ancient era, silk from China was the most lucrative and sought-after luxury item traded across the Eurasian continent,and many civilizations, such as the ancient Persians, benefited economically from trade.
Silkworm and the family
There are many indigenous varieties of wild silk moths found in a number of different countries. The key to understanding the great mystery and magic of silk, and China’s domination of its production and promotion, lies with one species: the blind, flightless moth, Bombyx mori. It lays 500 or more eggs in four to six days and dies soon after. The eggs are like pinpoints – one hundred of them weigh only one gram. From one ounce of eggs come about 30,000 worms which eat a ton of mulberry leaves and produce twelve pounds of raw silk. The original wild ancestor of this cultivated species is believed to be Bombyx mandarina Moore, a silk moth living on the white mulberry tree and unique to China. The silkworm of this particular moth produces a thread whose filament is smoother, finer and rounder than that of other silk moths. Over thousands of years, during which the Chinese practiced sericulture utilizing all the different types of silk moths known to them, Bombyx mori evolved into the specialized silk producer it is today; a moth which has lost its power to fly, only capable of mating and producing eggs for the next generation of silk producers.
The secret of sericulture
Producing silk is a lengthy process and demands constant close attention. To produce high quality silk, there are two conditions, which need to be fulfilled – preventing the moth from hatching out and perfecting the diet on which the silkworms should feed. Chinese developed secret ways for both.The eggs must be kept at 65 degrees F, increasing gradually to 77 degrees at which point they hatch. After the eggs hatch, the baby worms feed day and night every half hour on fresh, hand-picked and chopped mulberry leaves until they are very fat. Also a fixed temperature has to be maintained throughout. Thousands of feeding worms are kept on trays that are stacked one on top of another. A roomful of munching worms sounds like heavy rain falling on the roof. The newly hatched silkworm multiplies its weight 10,000 times within a month, changing color and shedding its whitish-gray skin several times. *The silkworms feed until they have stored up enough energy to enter the cocoon stage. While they are growing they have to be protected from loud noises, drafts, strong smells such as those of fish and meat and even the odor of sweat. When it is time to build their cocoons, the worms produce a jelly-like substance in their silk glands, which hardens when it comes into contact with air. Silkworms spend three or four days spinning a cocoon around themselves until they look like puffy, white balls.
Economical condition of silk fibre
World silk production has approximately doubled during the last 30 years in spite of man-made fibers replacing silk for some uses. China and Japan during this period have been the two main producers, together manufacturing more than 50% of the world production each year. During the late 1970’s China, the country that first developed sericulture thousands years ago dramatically increased its silk production and has again become the world’s leading producer of silk.
Geographic area and production
1.China … 96.2 million tonnes (15.4% of global wheat production)
2.India … 72 million (11.5%)
3. United States … 57.1 million (9.1%)
4. Russia … 45.5 million (7.3%)
5. France … 36.9 million (5.9%)
Silkworms are cultivated and fed with mulberry leaves. Some of these eggs are hatched by artificial means such as an incubator, and in the olden times, the people carried it close to their bodies so that it would remain warm.
Silkworms that feed on smaller, domestic tree leaves produce the finer silk, while the coarser silk is produced by silkworms that have fed on oak leaves. From the time they hatch to the time they start to spin cocoons, they are very carefully tended to. Noise is believed to affect the process, thus the cultivators try not to startle the silkworms.
Their cocoons are spun from the tops of loose straw. It will be completed in two to three days’ time. The cultivators then gather the cocoons and the chrysales are killed by heating and drying the cocoons.
In the olden days, they were packed with leaves and salt in a jar, and then buried in the ground, or else other insects might bite holes in it. Modern machines and modern methods can be used to produce silk but the old-fashioned hand-reels and looms can also produce equally beautiful silk.
History of the use of polyester:
States The first commercial production of polyester was by the du Pont de Nemours Company. It is the most used fibre in the United.
Production of polyester:
Polyesters are made from chemical substances found mainly in petroluem. Polyesters are manufactured in three basic forms – fibers, films and plastics.
Polyester fibers are used to make fabrics. Poly (ethylene terephthalate, or simply PET) is the most common polyester used for fiber purposes. This is the polymer used for making soft drink bottles. Recycling PET by re-melting it and extruding it as fiber saves much raw materials as well as energy.
PET is made by ethylene glycol with either terephthalic acid or its methyl ester in the presence of an antimony catalyst. In order to achieve high molecular weights needed to form useful fibers, the reaction has to be carried out at high temperature and in a vacuum.
Properties of the polyester:
1)It is resists wrinkling.
2)It is easy to launder.
3)It dries quickly.
4)It is resistant to stretching and shrinking
Describe systems and manufacturing processes relating to natural and man-made fibre and fabric production
Record and differentiate the key elements of manufacturing processes.
Natural and Man-Made Fiber Manufacturing
(At a glance)
Fiber Production & Blending
Most of you are at least generally familiar with the source and production of natural fibers. Therefore, the primary focus of this section is on the production of manufactured fibers. A discussion is also presented concerning the blending of both manufactured and natural fibers.
It should be kept in mind that the process for developing each manufactured fiber has been carefully selected to produce a fiber with specific characteristics important to its use in fabrications for apparel, home fashion and other textile products.
Distinction between Cellulosic and Non-Cellulosic Fibers
Regarding the production of manufactured fibers, a distinction should be made between cellulosic and non-cellulosic fibers. Four manufactured fibers, rayon, acetate, triacetate and lyocell, are cellulosic fibers. This means that one of the components used in their production is natural cellulose. Cellulose is wood pulp, generally obtained from trees. All of the remaining manufactured fibers are non-cellulosic, which means they are entirely chemically-based.
Production Chart for Acetate
To illustrate how man-made fibers are produced, below is a chart showing the production process for acetate fiber. Keep in mind that most manufactured fibers go through similar processes in their development. The production steps include:
- A chemical process
- A spinning process
- A twisting process
- The twisted yarn is then packaged and sent to the textile mills to be either woven or knitted into fabric.
Discussion of the Fiber Production Process
It is not intended to go into all the technical details in this presentation. However, some of the key parts of manufactured fiber production are useful to understand in a little more detail—namely, the spinning process and the process for making filament and staple fibers. The difference between filament and staple fibers is important to understand when discussing the blending of one or more fibers together.
In their original state, the various components of manufactured fibers are solids. In order to be extruded into fibers, the fiber-forming substances must first be converted into a liquid state. To accomplish this they are dissolved in a solvent or melted. If they can’t be dissolved or melted directly, they are chemically converted so they can be. The cellulosic fibers (rayon, acetate, triacetate and lyocell) come from purified wood pulp, which first must be shredded and then dissolved.
Spinning Process – The Spinneret
Before being formed into fibers, the fiber-producing substance for all manufactured fibers is in a thick liquid state. In the spinning process this liquid is forced through a spinneret, which resembles a large shower head. A spinneret can have from one to literally hundreds of tiny holes. The size of the holes varies according to the size and type of the fiber being produced.
Unlike natural fibers, manufactured fibers can be extruded in different thicknesses. This is called denier. Denier is a term you may have heard, and essentially relates to the fineness of the fiber filament. For example, a twelve (12)-denier monofilament is commonly used in sheer pantyhose, and a circular double-knit is about 140-denier.
As the thick liquid is forced through the spinneret, what comes out on the other side is a stringy liquid called filament. This stringy liquid is similar to airplane glue, which is a liquid acetate product. When the filament dries or solidifies, it forms what is called a continuous filament fiber. Strands of continuous filament fibers are then twisted together to form a continuous filament yarn, which is then woven or knit into fabric.
Staple Fibers and Blending
The long continuous filament fibers can’t be used for blending because they’re too long and too difficult to handle. Also, natural fibers, such as wool and cotton, with which many manufactured fibers are blended, are very short. Therefore, before blending, man-made fibers are first cut into short fibers, called staple fibers. The staple fibers can more easily be twisted with the shorter natural fibers, or with staple fibers of another manufactured fiber.
Staple fibers are created by extruding many continuous filaments of specific denier from the spinneret and collecting them in a large bundle called a “tow”. A tow may contain over a million continuous filaments.
Purposes of Blending
Blending of different fibers is done to enhance the performance and improve the aesthetic qualities of fabric. Fibers are selected and blended in certain proportions so the fabric will retain the best characteristics of each fiber. Blending can be done with either natural or manufactured fibers, but is usually done using various combinations of manufactured fibers or manufactured and natural fibers.
For example, polyester is the most blended manufactured fiber. Polyester fiber is strong, resists shrinkage, stretching and wrinkles, is abrasion resistent and is easily washable. Blends of 50 to 65% polyester with cotton provides a minimum care fabric used in a variety of shirts, slacks, dresses, blouses, sportswear and many home fashion items A 50/50 polyester/acrylic blend is used for slacks, sportswear and dresses. And, blends of polyester (45 to 55%) and worsted wool creates a fabric which retains the beautiful drape and feel of 100% wool, while the polyester adds durability and resistance to wrinkles.
Manufacturing process of manmade fiber
Polyester is a synthetic fiber derived from coal, air, water, and petroleum. Developed in a 20th-century laboratory, polyester fibers are formed from a chemical reaction between an acid and alcohol. In this reaction, two or more molecules combine to make a large molecule whose structure repeats throughout its length. Polyester fibers can form very iong molecules that are very stable and strong.
Polyester is used in the manufacture of many products, including clothing, home furnishings, industrial fabrics, computer and recording tapes, and electrical insulation. Polyester has several advantages over traditional fabrics such as cotton. It does not absorb moisture, but does absorb oil; this quality makes polyester the perfect fabric for the application of water-, soil-, and fire-resistant finishes. Its low absorbency also makes it naturally resistant to stains. Polyester clothing can be preshrunk in the finishing process, and thereafter the fabric resists shrinking and will not stretch out of shape. The fabric is easily dye able, and not damaged by mildew. Textured polyester fibers are an effective, no allergenic insulator, so the material is used for filling pillows, quilting, outerwear, and sleeping bags.
Polyester is a chemical term which can be broken into poly, meaning many, and ester, a basic organic chemical compound. The principle ingredient used in the manufacture of polyester is ethylene, which is derived from petroleum. In this process, ethylene is the polymer, the chemical building block of polyester, and the chemical process that produces the finished polyester is called polymerization.
Polyester is manufactured by one of several methods. The one used depends on the form the finished polyester will take. The four basic forms are filament, staple, tow, and fiberfill. In the filament form, each individual strand of polyester fiber is continuous in length, producing smooth-surfaced fabrics. In staple form, filaments are cut to short, predetermined lengths. In this form polyester is easier to blend with other fibers. Tow is a form in which continuous filaments are drawn loosely together. Fiberfill is the voluminous form used in the manufacture of quilts, pillows, and outerwear. The two forms used most frequently are filament and staple.
Manufacturing Filament Yarn
1 To form polyester, dimethyl terephthalate is first reacted with ethylene glycol in the presence of a catalyst at a temperature of 302-410°F (150-210°C).
2 The resulting chemical, a monomer (single, non-repeating molecule) alcohol, is combined with terephthalic acid and raised to a temperature of 472°F (280°C). Newly-formed polyester, which is clear and molten, is extruded through a slot to form long ribbons.
3 After the polyester emerges from polymerization, the long molten ribbons are allowed to cool until they become brittle. The material is cut into tiny chips and completely dried to prevent irregularities in consistency.
4 Polymer chips are melted at 500-518°F (260-270°C) to form a syrup-like solution. The solution is put in a metal container called a spinneret and forced through its tiny holes, which are usually round, but may be pentagonal or any other shape to produce special fibers. The number of holes in the spinneret determines the size of the yarn, as the emerging fibers are brought together to form a single strand.
5 At the spinning stage, other chemicals may be added to the solution to make the resulting material flame retardant, antistatic, or easier to dye.
Drawing the fiber
6 When polyester emerges from the spinneret, it is soft and easily elongated up to five times its original length. The stretching forces the random polyester molecules to align in a parallel formation. This increases the strength, tenacity, and resilience of the fiber. This time, when the filaments dry, the fibers become solid and strong instead of brittle.
7 Drawn fibers may vary greatly in diameter and length, depending on the characteristics desired of the finished material. Also, as the fibers are drawn, they may be textured or twisted to create softer or duller fabrics.
8 After the polyester yarn is drawn, it is wound on large bobbins or flat-wound packages,
ready to be woven into material.
Manufacturing Staple Fiber
In making polyester staple fiber, polymerization, drying, and melt spinning (steps 1-4 above) are much the same as in the manufacture of filament yarn. However, in the melt spinning process, the spinneret has many more holes when the product is staple fiber. The rope-like bundles of polyester that emerge are called tow.
Newly-formed tow is quickly cooled in cans that gather the thick fibers. Several lengths of tow are gathered and then drawn on heated rollers to three or four times their original length.
Drawn tow is then fed into compression boxes, which force the fibers to fold like an accordion, at a rate of 9-15 crimps per inch (3-6 per cm). This process helps the fiber hold together during the later manufacturing stages.
After the tow is crimped, it is heated at 212-302°F (100-150°C) to completely dry the fibers and set the crimp. Some of the crimp will unavoidably be pulled out of the fibers during the following processes.
Following heat setting, tow is cut into shorter lengths. Polyester that will be blended with cotton is cut in 1.25-1.50 inch (3.2-3.8 cm) pieces; for rayon blends, 2 inch (5 cm) lengths are cut. For heavier fabrics, such as carpet, polyester filaments are cut into 6 inch (15 cm) lengths.
Describe the different stages of processing and the quality control applied during production
Processing of Fibre:
The warping is the set of lengthwise yarns that are held in tension on a frame or loom. The yarn that is inserted over-and-under the warp threads are called the weft, woof, or filler. Each individual warp thread in a fabric is called a warp end or end. Warp means “that which is thrown across” (Old English wearp, from weorpan, to throw, cf. German werfen, Dutch werpen). Very simple looms use a spiral warp, in which a single, very long yarn is wound around a pair of sticks or beams in a spiral pattern to make up the warp.<href=”#cite_note-2″>
Because the warp is held under high tension during the entire process of weaving, warp yarn must be strong. Yarn for warp ends is usually spun and plied fibre. Traditional fibres for warping are wool, linen and silk. With the improvements in spinning technology during the Industrial Revolution, it became possible to make cotton yarn of sufficient strength to be used as the warp in mechanized weaving. Later, artificial or man-made fibres such as nylon or rayon were employed.
Weaving: Machine for woven fabric
Fig: Weaving looms sliding/picking/beating/let and take up motion.
It is the process of separating the warp threads into layers to from
tunnel, called shed thought which shuttle carrying weft passes is
known as shedding. Some warp threads are raised up and some are
depressed down to create the tunnel in the loom.
The method of passing the weft threads which traverses across the
fabric thought shed is called picking. The inset 4ed weft is known as
It is the process of pushing the pick into the reedy woken
fabric at a point known of feel of the cloth.
The motion which delivery warp in the weaving area
at the required rate and at a suitable constant tension by unwinding it
from a flanged beam called let-off motion.
Take up motion:-
The motion which withdrawals fabric from the weaving
area, at the constant rate that will gene the required spacing and winds
the fabric onto a roller is called take up motion.
There are two types of shed as:
Closed shed is classified on two parts.
(a) Bottom closed shed
(b) Centre closed shed
Open shed are classified on two parts.
(a) Semi-open shed
(b) Open shed
Knitting is a method by which thread or yarn may be turned into cloth or other fine crafts. Knitted fabric consists of consecutive rows of loops, called stitches. As each row progresses, a new loop is pulled through an existing loop. The active stitches are held on a needle until another loop can be passed through them. This process eventually results in a final product, often a garment.
Knitting may be done by hand or by machine. There exist numerous styles and methods of hand knitting. Different yarns and knitting needles may be used to achieve different end products by giving the final piece a different color, texture, weight, and/or integrity. Using needles of varying sharpness and thickness as well as different varieties of yarn can also change the effect.
Spinning is a major industry. It is part of the textile manufacturing process where three types of fibre are converted into yarn, then fabric, then textiles. The textiles are then fabricated into clothes or other artifacts. There are three industrial processes available to spin yarn, and a handicraft community who use hand spinning techniques. Spinning is the twisting together of drawn out strands of fibres to form yarn, though it is colloquially used to describe the process of drawing out, inserting the twist, and winding onto bobbins.
Dyeing is the process of adding color to textile products like fibers, yarns, and fabrics. Dyeing is normally done in a special solution containing dyes and particular chemical material. After dyeing, dye molecules have uncut Chemical bond with fiber molecules. The temperature and time controlling are two key factors in dyeing. There are mainly two classes of dye, natural and man-made.
In the last 150 years, humans have produced artificial dyes to achieve a broader range of colors, and to render the dyes more stable to resist washing and general use. Different classes of dyes are used for different types of fiber and at different stages of the textile production process, from loose fibers through yarn and cloth to completed garments.
In textile manufacturing, finishing refers to any process performed on yarn or fabric after weaving or knitting to improve the look, performance, or “hand” (feel) of the finished textile or clothing.<href=”#cite_note-kadolph330-0″> Some finishing techniques, such as fulling, have been in use with hand weaving for centuries; others, such as mercerisation, are byproducts of the Industrial Revolution.
Bio polishing removes the protruding fibers of a fabric through the action of an enzyme. Enzymes, such as cellulose for cotton, selectively remove protruding fibers. These enzymes may be deactivated by an increase in temperature.
Mercerization makes woven cotton fabric stronger, more lustrous, to have better dye affinity, and to be less abrasive.
Rising lifts the surface fibers to improve the softness and warmth, as in <href=”#Flannelette” title=”Flannel”>flannelette.
Peach Finish subjects the fabric (either cotton or its synthetic blends) to emery wheels, making the surface velvet-like. This is a special finish used mostly in garments.
Sanforizing or Pre-shrinking prevents a fabric and the produced garment from shrinking after production. This is also a mechanical finish, acquired by feeding the fabric between a roller and rubber blanket, in such a way the rubber blanket compresses the weft threads and imparts compressive shrinkage.
Crease-Resist finish or “wash-and-wear” or “wrinkle-free” finishes are achieved by the addition of a chemical resin finish that makes the fiber take on a quality similar to that of synthetic fibers.
Anti-microbial finish causes a fabric to inhibit the growth of microbes. The humid and warm environment found in textile fibers encourages the growth of the microbes. Infestation by microbes can cause cross-infection by pathogens and the development of odor where the fabric is worn next to skin. In addition, stains and loss of fiber quality of textile substrates can also take place. With an aim to protect the skin of the wearer and the textile substrate itself, an anti-microbial finish is applied to textile materials.
Special finishes for synthetic fibers
Heat setting of synthetic fabrics eliminates the internal tensions within the fiber, generated during manufacturing, and the new state can be fixed by rapid cooling. This heat setting fixes the fabrics in the relaxed state, and thus avoids subsequent shrinkage or creasing of the fabric. Presetting of goods makes it possible to use higher temperature for setting without considering the sublimation properties of dyes and has a favorable effect on dyeing behavior and the running properties of the fabric.
Stiffening and filling process: A stiffening effect is desirable in certain polyamides and polyester materials (e.g. petticoats, collar inner linings), which can be done by reducing the mutual independence of structural elements of fabric by polymer deposition on coating as a fine film.
Hydrophilic finishes compensate for lower moisture and water absorption capacity in synthetic fiber materials, which become uncomfortable in contact with skin. Certain products, based on modified (oxy-ethylated) polyamides, make the fabric more pleasant by reducing the cohesion of water so that it spreads over a larger area and thus evaporates more readily.
Anti-pilling finish alleviates pilling, an unpleasant phenomenon associated with spun yarn fabrics, especially when they contain synthetics. Synthetic fibers are more readily brought to the surface of a fabric due to their smooth surface and circular cross-section, and due to their higher tensile strength and abrasion resistance.
Anti-static finish prevents dust from clinging to the fabric. Anti-static effective chemicals are largely chemically inert and require Thermasol or heat treatment for fixing on polyester fabrics. Polyether agents have been found to be useful but should not affect the dye-equilibrium on fiber, lest they impair the rubbing fastness. In general, Thermasol anti-static agents also have a good soil release action, which is as permanent as the anti-static effect. Anti-static finishes may also be of polyamide type, being curable at moderate temperatures.
Non-slip finishes give the filaments a rougher surface. Synthetic warp and weft threads in loosely-woven fabrics are particularly prone to slip because of their surface smoothness when the structure of fabric is disturbed and appearance is no loner attractive. Silica gel dispersions or silicic acid colloidal solutions are used in combination with latex polymer or acrylates dispersions to get more permanent effect, along with simultaneous improvement in resi