Carpet Fibers and Yarn:
Fiber Market Share:
The major fi ber used in broadloam carpet is nylon which represents about 2/3 of the market. Polypropylene, polyester, wool, and some acrylic and cotton fiber is also used to produce carpet.
Market Share
Nylon 62.3%
Olefin 31.5%
Polyester 5.8%
Wool .42%
Definition of Fiber:
A fiber as it relates to carpet is any substance that can be made into yarn. It is a single, fine, hair-like unit. A single fiber is the smallest unit of yarn that can be processed by weaving, tufting, knitting or fusion bonding.
Not all fibers are made into yarn. Some are instead made directly into a product. Examples of this would be non-woven backing fabrics, and needle punched textiles, such as those that are used for felt, or some outdoor carpets or pads.
Natural and Manmade Carpet Fibers Defined:
Both natural and manmade fibers are used in the fabrication of both carpet face and back. Through the years these fibers have continued to change. Wool was once the primary face yarn and polypropylene the primary backing material.
Natural Fiber: A natural fiber is obtained from animals, plants or minerals. A variety of natural fibers are used in the manufacturing of carpet yarn, backing systems and cushion.
1. Animal Fiber: Animal fibers are the fibrous, usually crisp growth that forms the covering of an animal to provide warmth and protection. Animal fibers are very tough but the degree of toughness is not the same with all animal fibers. New Zealand is the world\'s largest single source of carpet wool traded internationally. The high quality of this wool is based on long-term investment in scientific sheep breeding, as well as agricultural land management techniques.
Animal hair is also used to manufacturer some felted style carpet pad. Silk is also considered an animal fiber even though it comes from the cocoon of a silkworm. While silk is not used to manufacturer broadloom carpets it is found in some oriental rugs.
2. Plant fiber (cellulosic) Cotton has been the primary plant fiber used to make carpet yarn. Jute is the predominant plant fiber that has been used in carpet backing and padding. Jute is the common name of two Asian plants, Corchorus or capsularis or C. olitorious. Most jute comes from the watershed of the Ganges River in India and Bangladesh.
3. Mineral fiber: Glass and asbestos are mineral fibers. These fibers are not used in the manufacturing of carpet.
4. Man-made fiber (Manufactured, Synthetic)
Most of the manmade fibers used in the manufacturing of carpet are produced from petrochemicals. These petrochemicals represent about 2% of each barrel of crude oil. Examples of fibers formed as a result of chemical (petrochemical) synthesis would be nylon, olefin, result of chemical (petrochemical) synthesis would be nylon, olefin, polyester and acrylics. A variety of petrochemicals are produced, and each generic fiber is produced from different petrochemical and has its own unique characteristics. Fiber properties are altered through the use of polymer additives. These additives are used to change a fiber\'s characteristics such as luster and dyeability.
Manmade fibers are also produced from plants and minerals. Examples of these fibers would be acetate and rayon which are cellulose based fibers produced from modified or transformed natural polymers found in cotton or wood, and glass fiber which is mineral fiber.
Yarn Defined:
Yarn: A yarn is a group of single fibers that have been grouped and twisted (plied) together into a continuous strand.
Yarn Ply: is a measure of the number of individual yarns twisted together to produce the finished yarn. The most common yarn used in carpet is a 2-ply. The number of plies is generally selected to achieve a particular appearance and is not a measure of its quality or performance.
Spun Yarns: (staple) are composed of relatively short lengths of fiber that are twisted or spun together. The short lengths of fiber (staple) are made into yarn by mechanical processes which first make the fibers more or less parallel, then alternately pull and twist them.
Filament Yarns: are composed of continuous strands of fiber which may be miles long. These yarns, know as BCF or Bulked Continuous Filament, are produced directly from spinnerette. Silk, which is produced from a silk cocoon, is also considered a filament yarn.
Woolen Yarn: spun yarn, composed of any natural or synthetic fiber, manufactured by the woolen system spinning process. Compared to worsted system or parallel spun yarns which are common to most tufted carpets, woolen yarns are soft, bulky, and hairy. Staple for woolen spinning is short, in the 3.5 to 5.5 inch range.
Worsted Yarn: is made of long staple carpet fibers and combed using a series of combs or large cylinders with comb-like teeth, to straighten the fibers and remove the extremely short fibers.
Spinning Methods: Woolen Spinning is an older spinning method set up to spin short 3.5" - 5.5" wool fibers, and more recently for acrylic fibers. This system produces bulky, hairy yarn, usually used for wool yarns. A series of cards randomly overlay the fibers rather then combing them into uniform parallel silvers. This is a less complex system than parallel spinning.
Worsted spinning is a method by which wool is converted into yarn by carding, gilling, combing, back-washing, raving reducing and spinning.
Parallel Spinning: The method most commonly used in spinning nylon staple fiber into yarn. Fibers measuring 6" 8" are paralleled by carding, combing and drafting (8:1 pin drafter) until they form extremely smooth, constant, constant-density silbers. The final silber is put on a spinning frame and further drawn (elongated) as a twist is applied, thus turning the fiber into a cohesive singles yarn that is ready to be plied and heat set.
Woolen and Worsted Spinning Production:
Wool and other natural yarns begin with the raw stock that goes through varied processes before being spun into yarn.
Preparation Processes Common to Woolens and Worsteds
1. Sorting or dividing into qualities, classing.
2. Cleaning, usually required to some extent. Unwashed wool contains yolk, which is a fatty or greasy matter that is secreted from the skin of the sheep; it also contains dust, dirt, burrs, etc. which cling to the fleece. Before wool can be made into yarn it must be dusted and opened before scouring and if it is full of burrs it will require carbonizing. While the series of steps that are used to produce wool will differ, the following processes are common to woolens and worsteds.
3. Scouring, for greasy or half washed wools. If the wool is reasonably clean it may only require scouring to prepare it for carding, but if it is full of impurities, it will need to go through cleaning first.
4. Dyeing in the wool or raw stock dyeing, used often with woolens.
5. Drying.
6. Burring. Needed when wool is full of burrs, which is frequently the case with short staple wools.
7. Oiling (sometimes done before blending). Care must be taken to assure that enough lubricant is supplied for production purposes. If too much lubricant is provided the yarn will attract soil; if too little is added, the traveller will seize.
Spinning:
All Synthetic carpet fibers are extruded through a spinnerette with the most extruded carpet material being nylon polymer. The polymer chips are melted into syrup like substance. The molten material is then forced through tiny holes in a form that is called a spinnerette, similar to water passing through a shower head. As the molten material passes through the spinnerette it takes the shape of the openings, developing an unlimited variety of configurations such as round, triangular, trilobal, or other form. The size of the openings can also be varied to produce fiber that is finer than silk or heavier than horse hair.
A small spinnerette has only about 10 holes while a large spinnerette may have more than 10,000 holes. For continuous filament yarn, the number of holes will be equal to the number of filaments that the yarn bundle will contain. Smalller spinnerettes are used for fibers that are to remain as continuous filament. Large spinnerettes with many holes are used to produce yarn that is to be cut into staple and this is a basic reason why staple fiber is less expensive on a per pound basis than a comparable continuous filament fiber.
Once the fiber is extruded through the spinnerette and becomes exposed to the air, the cooling fiber strands harden. A variety of techniques are used to harden the streams of molten liquid and produce the filament fiber. The technique that is used will depend upon the solution's chemical composiion.
Drawing or Stretching: While the shape of the fiber was determined when it passed through the spinnerette, the the fiber still lacks orientation and the molecular chains in the filament fibers must be placed in a more orderly fashion. Once the fiber has hardened, this orientation is achieved by drawing or stretching the fiber 4 times its original length which will reduce their diameter and rearrange their molecules so they are made parallel to each other. The stretching is precisely controlled so that it imparts the desired crystallinity, tenacity and elongation to the fiber. Drawing or stretching is important for the fiber's ultimate strength or elasticity.
Bulking (Texturizing or Crimping):
Once the fiber has been drawn it is bulked usining high heat. This process is also know as texturizing or crimping and it imparts texture/fullness to the fiber or yarn during production. Bulking increases coverage and the bloom the yarn will have, and also makes the fiber more resilient.
BCF Chopped into Staple Lengths:
Up to the texturizing stage the fiber is still one long continuous strang and is referred to as BCF Bulked Continuous Filament. Some carpets are produced with "Staple" yarn. To produce staple, the continuous filament yarn is chopped into shorter lengths, routinely about 4" to 8" for carpet yarns and then baled for future spinning in the same method that natural fibers are spun.
Singles Yarn Spinning:
The silver yarn is now formed into singles yarn "End". The yarn is strengthened by inserting twist while reducing the silver in size to its desired dimension. At this point, the singles "End" is ready for plying.
Plying:
Multiple "Ends" of Staple or BCF yarn can be twisted (plied) into the desired yarn form.
Heat-Setting:
Once the yarns have been plied they go through a heat-setting process to set the twist, stabilize the yarn configuration and deter the yarn bundles from opening in use.
The yarn is now ready for packing and shipping.
How low Aborbency Factors Relate to Synthetic Carpet
Fiber:
Natural or man-made objects having very high aspect ratios, that is, having length hundreds to thousands of times greater then their widths. Useful textile fibers have high tensile strengths, flexibility, and resistance to heat, light, chemical, and abrasives. Any substance which can be made into a yarn.
Advantages:
a. Stains are easier to remove
b. Less Shrinkage
c. Better recovery when cleaned
Disadvantages:
a. Static build up due to low moisture content
b. Dirt is drawn to the fiber due to static build-up
Fiber Shapes:
Each fiber has its own identifying properties. When you view carpet fibers with the naked eye, they all look the same shape. When these same fibers are viewed under a microscope different shapes and configurations can be seen.
A fiber's shape and surface construction determine factors such as luster, bulk, texture, and hand. A fiber that is larger in diameter will be bulkier as the large diameter fiber does not pack as easily as a thin diameter fiber. Wool, a round fiber, is bulkier than cotton which is a flat fiber. A round-shaped, rod-like fiber, such as nylon, has a smoother, more slippery hand than wool, which is also round but has a surface that is scaly. Synthetic carpet fibers also have shapes that are unique to that product.
Round fibers reflect light in a single direction giving them a shiny surface. Multilobal-shaped fiber will scatter the light giving it a duller appearance and thus it has better soil hiding qualities.
Acrylic:
A manufacturer fiber in which the fiber-forming substance is any long-chain synthetic polymer composed of at least 85% by weight of acrylonitrile units, a liquid derivative of natural gas and air. Acrylic is a lightweight manufacturer fiber with a wool-like hand. In 1950, E.I. dupont de Nemours & Company, Inc. became the first company in the United States to commercially produce acrylic. Acrylic went into full production in 1952 and was first introduced in carpet in 1957. In 1988 acrylic fibers disappeared from the market due to superior performance from the other synthetics. in 1990 acrylic was rentroduced in Berber styling due to a demand for its wool like appearance.
Advantages:
a. Appearance and feeel of wool without the cost
b. Resist abrasion
c. Low static level
d. Mositure and mildew-resistant
e. Excellent resistance to sun light
f. Available in loop and cut pile
Disadvantage:
a. It has a tendency to fuzz and pill in coarse gauge loop pile
b. Poor soil resistance
c. Poor resistance to burning. While flame retardant variants are available they release toxic gases (contains cyanide group)
d. Limited resistance to some organic solvents and strong alkali
e. Only fair strength becoming about 20% weaker when wet
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