Wednesday, December 25. 2019How they make clothes to fit almost everyone?
The traditional tailor can take account of long arms or a spreading waistline and achieve a perfect fit. But made-to-measure clothes get more expensive every year, and the modern clothing industry has to make off-the-peg clothes that fit most people with no alteration. One of the first proper surveys into people’s measurements was carried out by US Government, who measured 1000 recruits during the First World War to determine the best sizes for uniforms. In Britain, 5000 women were measured in the early 1950s, with some unexpected results. Existing size charts were based on an average height for women of 5ft 6in (168cm) – but the survey found that the real average was 5ft 3in (160cm). Today, in large companies, from a basic pattern produced by a designer, a computer produces a range of sizes to cover the normal variations of the population. Unusually small or large people complain that they can never find anything to fit them, and they are right; it does not make economic sense for manufacturers to produce the limited number of garments that would be sold. The next step is to use the patterns to cut out the material for the garment. Rolls of material, which can be more than 100ft (30m) long, are laid out perfectly flat by machine. Hundreds of layers are spread on top of one another so that a large number of garments can be cut out at once. Computers are used to arrange the patterns on the material so that the minimum of cloth is wasted. A paper computer printout, called a marker, is laid on the layers of fabric ready for cutting. The actual cutting of the material is done by knives guided from above, or in some modern factories, by laser beams controlled by computers. The laser, an intense beam of light, burns a clean cut through the material, far sharper than the cut of any knife. Next, the pieces of material have to be sewn together. Many operations, such as buttonholing, can be done automatically. A hand-sewer averages 20 stitches a minute; modern machinery can sew up to 7000 stitches a minute. Some clothes are not stitched in the traditional way at all, but fused together. Finally clothes are pressed, to mould them into the right shape and to make sharp creases or pleats. Special presses, called buck presses, are designed for each part of a garment.
Picture Credit : Google Wednesday, December 25. 2019How to put the patterns into clothes?
The Chinese have been exchanging gifts of richly patterned fabrics for thousands of years. At about the time of Christ’s birth the wife of a Chinese nobleman, Ho Kuang, gave another, Shunyu yen, ‘twenty-four rolls of a silk brocade with a grape design, and twenty-five rolls of thin silk design, and twenty-five rolls of thin silk woven with a pattern of scattered flowers.’ The Chinese mastered the art of weaving, using silk threads of many colours and complex weaves to produce brocades and tapestries. With primitive looms, weaving patterns into cloth was a job that needed a great deal of skill and patience. Even with the inventions of the 18th century, a weaver had to know which of the warp threads (running down the length of the loom) to lift and which to leave to make a pattern. Only the threads that were lifted would be woven into the design when the shuttle carrying the weft (the threads running across the loom) was ‘thrown’ across the loom. It was not until the beginning of the 19th century that a French silk weaver, Joseph Jacquard, found a way to make detailed patterns without skilled weavers. A chain of cards punched with holes was attached to a rotating block above the loom. Only where there were holes could threads be picked up by small hooks and become woven into the pattern. After each card had been used to make a small part of a pattern, the block was given a quarter-turn, bringing the next card into place. It took 24,000 cards to weave a silk portrait of Jacquard, so accurate that it could hardly be distinguished from a portrait in oils. The cards were tied together in a long strip which slowly passed over the loom. Jacquard looms are still used to make luxury fabrics. Many patterned fabrics can be woven on simpler machines. The timeless patterns of tweed are still woven on hand looms. The direct printing of patterns onto woven fabrics originated in India, and the first printed calicos were brought to Europe in the 16th century. From the Hindi word ‘tchint’ comes ‘chintz’, which we still use to describe printed fabrics that are glazed to give them a slight sheen. Modern textile printing uses metal rollers on which the design is engraved, with each colour applied by a different roller. The rollers pass through a colour trough as they rotate and then transfer the dye to the fabric. As many as 16 rollers may be used to produce a fabric. Electronic control ensures that each successive roller matches its patterns perfectly with the one before. As the fabric comes off the final roller it passes through an oven where it is dried. Modern machines can print in 16 colours at speeds of 200yds (180m) of fabric a minute.
Picture Credit : Google Wednesday, December 25. 2019How silk was made in traditional Chinese way?
For thousands of years silk has been traded from East to West, and it is still the most precious fabric by weight. Silk is a fibre spun by the domestic silkworm, Bombyx mori, to create a cocoon in which it turns into a moth. Each cocoon consists of a single filament up to 1 mile (1.6km) long. It takes 110 cocoons to make a tie, 630 for a blouse and 3000 for a kimono. Chinese legend dates the discovery of silk to the year 2640 BC, in the garden of Emperor Huang Ti. According to the story, Huang Ti asked his wife, Xi, Lingshi, to find out what was eating his mulberry trees. She discovered it was white worms that spun shiny cocoons. Dropping one by accident into warm water, she found that she could draw out a fine filament, and wind it onto reels. She had discovered how to make silk, and it remained a Chinese secret for the next 2000 years. Imperial law decreed that anybody revealing the secret would be tortured to death. Manufacturing silk has four stages: the cultivation of mulberry trees, the raising of silkworms, the reeling of the silk fibre from the cocoons, and the weaving of fabric. Silkworms will eat the leaves of a variety of trees – one type of silkworm feeds on oak leaves – but mulberry leaves produce the finest silk. In 1608 King James I ordered 10,000 black mulberry trees to be planted across England to create a domestic silk industry, but the project failed. He had unfortunately chosen the wrong variety – silkworms prefer the white mulberry. In China the mulberries are cultivated as low bushes, so their leaves can be easily harvested and fed to the silkworms. Silkworms are raised in the spring, in two months of intensive activity. The eggs, stored in a cool place from the previous season, are incubated as soon as the mulberry bushes come into leaf. They take about eight days to hatch, then the worms feed continuously on the mulberry leaves for almost a month. They increase their body weight 10,000 times in his four-week period. Even breathing does not interfere with their eating, because they breathe through holes in their bodies. To be productive, silkworms must be cosseted. In China it was said that the worms liked warmth and hated cold, liked dryness and hated damp, liked cleanliness and hated dirt. But they were also said to dislike noise, the odour of frying fish, tears, shouting and women who were pregnant or had just give birth. Even today, in the Chinese province of Hangzhou, the women who look after the silkworms are forbidden to smoke, wear make-up, or eat garlic. After their fourth moulting the silkworms set about making their cocoons. They begin to exude a semiliquid mixture from the two silk glands that run the length of their bodies. The single thread which emerges is made up of the two threads joined together. First they anchor themselves by making a fine net. Then tossing their heads in a figure-of-eight motion, they slowly build up a waterproof cocoon that completely surrounds them. It takes a worm about three days to spin the entire cocoon, during which it will have shaken its head about 300,000 times. Left to its own devices the worm will turn into a moth in about two weeks, exude an enzyme to weaken the cocoon and emerge to begin the life cycle once more. In practice only a few are allowed to do this, to provide for the following year. The rest are killed. By preventing the cocoon being damaged by the emerging moth, an unbroken thread can be recovered. The process of obtaining the thread is called reeling. It is done by soaking the cocoons in warm water, finding the end of each silk thread and winding it onto a reel. Fibres from several cocoons, usually between five and eight, are wound on to the same reel to make a thread of sufficient thickness. Today automatic reeling machines do much of the work. If two silkworms are placed together they create a twin cocoon. The silk that emerges is known as dupion. It has ‘slubs’ or lumpy places along the thread and is used to make fabrics with variations in texture. World production of silk is small, around 50,000 tons a year, only a fifth of 1 per cent of total textile fibres. Its shimmering texture is created by fibres that are not round but triangular, and therefore reflect the light. It still makes the best ties and the most luxurious underwear.
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