Rug" by Being Fixed to the Floor Surface and Extending Wall to Wall
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Background Carpet is a textile floor covering that is distinguished from the more general t erm "rug" by being fixed to the floor surface and extending wall to wall. The ea rliest peoples covered the floors of their dwellings with animal skins, grass, o r, later, woven reed mats. When people learned how to spin cotton and wool, wove n mats of these materials largely replaced earlier coverings. Around 3000 B.C. E gyptians sewed brightly colored pieces of woolen cloth onto linen and placed it on their floors. The first carpets of note were woven by nomads. The thick carpets were easy to t ransport and were placed over the sand floor of tent dwellings. Early looms were similarly easy to transport. Two forked branches were joined by a crosspiece ho lding the suspended warp, and a wooden bar was used to flatten binding weft thre ads, while the loose warp ends formed the carpet's pile. The Pazyryk carpet has been documented as the earliest hand loom carpet, dating back from 500 B.C. and discovered in a tomb located in the Alti Mountains in Central Asia. From these early beginnings, carpet weaving rose to its highest art form in Turk ey, Iran, India, and China. Using cotton, linen, or hemp as the foundation, and wool or silk as the luxurious pile, weavers would make a knot out of the pile th read, then form a row of knots that was tightly beaten down. The process was tim e-consuming: some of the finest handmade carpets have as many as 2,400 knots per square inch (372 knots per sq cm). The brilliant colors of these ancient carpet s came from natural dyes such as madder, indigo, genista, woad, and ocher. Some weavers added alum to these dyes to fix the color, and a few wove gold and preci ous jewels into their carpets. While Europeans for centuries eagerly received carpets ready-made from the Middl e East, carpet making itself did not find a firm foothold on the continent until France imported Moorish weavers around A.D. 1300. By 1600, carpet guilds were f lourishing around Aubusson and Savonnerie. England also imported Persian weavers , as well as French ones, and by 1700 both Wilton and Axminster, known for their wool, were chartered carpet-making towns. Carpet making in Europe started with the "Brussels weave" in France and Flanders. This weave is formed by putting yar n over rods to create uncut loops. Wilton carpets are cut by a blade that replac es the rod in the Brussels weave. In 1801, Joseph M. Jacquard invented a device for handlooms that used punch cards to place up to six varieties of yarn colors in textiles, thus increasing production. This technique was adopted for carpet l ooms in 1825. The first carpet factory in the U.S. was built by William Sprague in Philadelphi a in 1791. His looms, based on English inventions, could make 27-inch (69-cm) ru nners that could be sewn together to make larger carpets. By 1800, 6-8 yards (7- 9 m) of carpet could be made in a day. Erastus Bigelow built a mill in 1825 in C linton, Massachusetts, and invented the power loom in 1839, which doubled carpet production. He also invented the first broadloom in 1877. Power looms improved over the years; soon one loom could make 75 yards (82 m) of high quality carpet a day. Carpet production changed dramatically at the beginning of the 20th century, beg inning inauspiciously with a burst of tufted bedspread production in Dalton, Geo rgia, led by young entrepreneur Catherine Evans Whitener. Tufting is the process of punching yarn into a ground fabric to create many uncut loops at a very fast pace. Tufted bed-spread factories dominated the Dalton area by World War II, an d they soon began producing tufted rugs as well. Demand for these roughly made r ugs was as great as that for the bedspreads. At first using cheap, readily avail able cotton before switching to synthetic yarns, the number of Dalton carpet mak ers grew as they produced great amounts of relatively easy-to-make broadloom tuf ted rugs and, eventually, carpets. Carpet, once a luxury, became affordable for most Americans. Today, carpet makes up 72% of all flooring, with tufted carpet b eing 91.5% of production, and the city of Dalton is responsible for over 70% of the world's production of carpet. Raw Materials Carpet consists of dyed pile yarns; a primary backing in which the yarns are sew n; a secondary backing that adds strength to the carpet; adhesive that binds the primary and secondary backings; and, in most cases, a cushion laid underneath t he carpet to give it a softer, more luxurious feel. Ninety-seven percent of pile yarns today are made up of synthetic polymers; the rest of the yarns are wool and comprise the more expensive, woven carpet. Synthe tics are plastics such as nylon (which is in 66% of all carpet), acrylics (15%), polyester (less than 15%), and polypropylene (less than 5%). These pile yarns a re dyed using a variety of organic chemical compounds, or occasionally, organome tallic complexes. Both the primary and secondary backing are largely made of woven or nonwoven pol ypropylene, though some secondary backing may still be made of jute, a natural f iber that, when woven, looks like burlap. The adhesive used to bind the backings together is almost universally synthetic rubber latex. The most common padding is rebond (bonded urethane), though various forms of synthetic latex, polyuretha ne, or vinyl might be used instead. Rebond is recycled scrap urethane that is ch opped into uniformly sized pieces and pressed into layers. Although rare, some c arpet cushioning is made up of horse hair or jute. A plastic top sheet is usuall y added to the top to insure a smooth surface against the carpet. The Manufacturing Process Since most carpet in the U.S. is tufted; earlier methods of weaving carpet, such as Wilton and Axminster, are ignored in the following account. Preparing the yarn Synthetic yarns arrive at the carpet manufacturer either in staple fiber for m or bulk continuous filament form. The staple fibers, which average 7 inches (1 8 cm) long, are loose, individual strands that arrive in bales. Several bales ar e blended together into one batch in a hopper. Then, after lubrication, they are spun into long, loose ropes called slivers by a carding machine. The slivers ar e then pulled, straightened, and spun into single yarn that is wound onto spools . Both the single-ply staple fibers (now spun into filament) and the bulk contin uous filament must now be twisted together to form thicker twoply yarn suitable for tufting. The yarns are then steamed to bulk them, and then heated to 270-280°F (132-138°C). This heat setting causes the yarn to maintain its shape by fixing it s twist. After cooling, these yarns are wound onto tubes and transported to the tufting machines. Dyeing the yarn Most carpets are dyed after tufting, yet sometimes the yarns are dyed first. The methods include putting 500-1,000 pounds (227-455 kg) of fiber into pressur ized vats through which treated dyes are circulated, or passing the fiber contin uously through the bath, or passing skeins of yarn through the vat of dye. The y arn can also be put on forms, and the heated dyes can then be forced under press ure from inside the forms to color the yarn. Another method passes the yarn thro ugh printing rollers, while yet another involves knitting the yarn onto a form t hat is then printed with dyes before the yarn is unraveled. All yarn that has be en dyed is then steamed, washed, and dried. Tufting the carpet The yarn is put on a creel (a bar with skewers) behind the tufting machine, then fed into a nylon tube that leads to the tufting needle. The needle pierces the primary backing and pushes the yarn down into a loop. Photoelectric sensors control how deeply the needles plunge into the backing, so the height of the loo ps can be controlled. A looper, or flat hook, seizes and releases the loop of ya rn while the needle pulls back up; the backing is shifted forward and the needle once more pierces the backing further on. To make cut pile, a looper facing the opposite direction is fitted with a knife that acts like a pair of scissors, sn ipping the loop. This process is carried out by several hundred needles (up to 1 ,200 across the 12 foot [3.7 ml width), and several hundred rows of stitches are carried out per minute. One tufting machine can thus produce several hundred sq uare yards of carpet a day. Dyeing the tufted carpet For solid color carpeting, carpet of several standard roll lengths is sewn t ogether to make a continuous roll, which is then fed into a vat. The vat is fill ed with water, which is first heated before dyes and chemicals are mixed in. The mixture is then slowly brought to a boil and cooked for four hours. Another met hod of making solid color carpet is to sew several rows together to make one con tinuous roll, which is then fed under rods that bleed the color into the pile. A fter dyeing, the carpet is then steamed to fix the color, excess color is washed off, and the carpet is dried and put on a roll.