Polyester



Background

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 dyeable, and not damaged by mildew. Textured polyester fibers are an effective, nonallergenic insulator, so the material is used for filling pillows, quilting, outerwear, and sleeping bags.

History

In 1926, United States-based E.I. du Pont de Nemours and Co. began research into very large molecules and synthetic fibers. This early research, headed by W.H. Carothers, centered on what became nylon, the first synthetic fiber. Soon after, in the years 1939-41, British research chemists took interest in the du Pont studies and conducted their own research in the laboratories of Calico Printers Association, Ltd. This work resulted in the creation of the polyester fiber known in England as Terylene.

In 1946, du Pont purchased the right to produce this polyester fiber in the United States. The company conducted some further developmental work, and in 1951, began to market the fiber under the name Dacron. During the ensuing years, several companies became interested in polyester fibers and produced their own versions of the product for different uses. Today, there are two primary types of polyester, PET (polyethylene terephthalate) and PCDT (poly-1, 4-cyclohexylene-dimethylene terephthalate). PET, the more popular type, is applicable to a wider variety of uses. It is stronger than PCDT, though PCDT is more elastic and resilient. PCDT is suited to the heavier consumer uses, such as draperies and furniture coverings. PET can be used alone or blended with other fabrics to make clothing that is wrinkle and stain resistant and retains its shape.

Raw Materials

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

The Manufacturing
Process

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

Polymerization

Drying

Melt spinning

Polyester

Drawing the fiber

Winding

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.

Drawing tow

Crimping

Setting

Cutting

The Future

Following its introduction to the United States in 1951, polyester quickly became the country's fastest-growing fiber. Easy care of the permanent press fabric made polyester doubleknits extremely popular in the late 1960s. However, polyester has suffered an "image problem" since that time, and clothes made out of polyester were often devalued and even ridiculed. Several new forms of polyester introduced in the early 1990s may help revitalize the image of polyester. A new form of polyester fiber, called microfiber, was introduced to the public in 1991. More luxurious and versatile than traditional polyester, microfiber fabrics are difficult to tell apart from silk fabrics. Clothing designers such as Mary McFadden have created a line of clothes using this new form of polyester. Textile researchers at North Carolina State University are developing a form of polyester that may be as strong as Kevlar, a superfiber material used to make bulletproof vests. This type of polyester may eventually be used as composite materials for cars and airplanes.

Where To Learn More

Books

Corbman, Bernard P. Textiles: Fiber to Fabric. 6th ed. Gregg Division, McGraw-Hill, 1983, pp. 374-92.

Encyclopedia of Textiles. 3rd ed. Prentice-Hall, Inc., 1980, pp. 28-33.

Polyester: Fifty Years of Achievement. State Mutual Book & Periodical Service, 1993.

Periodicals

Fellingham, Christine. "Will You Learn to Love Polyester?" Glamour, April 1992, p. 204.

Templeton, Fleur. "Show Me a Bulletproof Leisure Suit, In Pink." Business Week, July 6, 1992, p. 65.

Thomas, Marita. "At 50 Years, Polyester Gains New Fashion Vitality." Textile World, December 1993, p. 62+.

Kristine M. Krapp

Also read article about Polyester from Wikipedia

User Contributions:

1
raghu t s
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Sep 19, 2006 @ 6:06 am
oil is more viscous than water how can you say polyster absorbs the oil
2
jasmin
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Aug 8, 2007 @ 6:18 pm
needs more diagrams of the process in which polyester is made
3
annonomus
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Oct 21, 2009 @ 3:15 pm
i thought it was awesome, gave me a lot of info for my science fair project
4
hello
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Jun 22, 2011 @ 3:03 am
This is a very usefull page but do you now what is the energy input for making polyester?
5
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Jun 30, 2011 @ 3:15 pm
Spinning of Polyester Filament Yarn

The polyester polymer produced from PTA and MEG is extruded in the form of a ribbon. This ribbon is then converted into chips.
These chips received in the bulk packing of 750 kgs to 1250 kgs

The wet chips are dried with hot dehumidified air in the continuous dryer and fed through a hopper to the extruder for melting at high temp 285 C. This molten polymer is then extruded under high pressure through spinnerettes down to cylinder. In the form of continuous filaments

Each spinnerette contains 12 to 196 holes. A cool controlled air is blowing across the bunch of filaments for proper cooling. A spinning finish is applied at this stage as a lubricant and an antistatic agent. The yarn is partially drawn between the spinnerettes and the spin finish applicator before it is wind at very high speed on winders in the form of cheeses.
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the yarn produced is deoffed from the winders checked for the properties and packed in the pallets of 60 spools each.
6
Jenny
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Dec 20, 2012 @ 8:08 am
But what does wearing this petro chemically derived material mean for our long term health??
7
M.farrukh
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Aug 12, 2013 @ 6:06 am
good information, why polyester makes over lapping in drawing simplex and ring spinning process? and what is remedy ?
8
homa
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Sep 3, 2013 @ 4:04 am
to ajay:
first yarn is drawn after oil finishing and befor winding,between spineret and spin finish applicator there isnt any drawing area
second oil finishing is not just for anti statin effect,it is mainly for sticking filaments together
9
Enid Hartwig
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Nov 8, 2014 @ 6:06 am
Are either of the compounds cobalt dichloride or thiuram mix used in the manufacture of polyester or in the material itself. Have an allergy to these 2 compounds and am trying to trace what is causing my itch.
10
Gig
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Feb 23, 2015 @ 10:22 pm
With being chemically sensitive, I now know why I can not wear polyester clothes or have it in sheets. The itch and rash is horrible.

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