Polyester: The Plastic of Our Lives

Saturday, July 19, 2014


It seems these days everyone is wearing plastic. Polyester and other synthetics have made inroads in apparel in ways not seen since the days of double-knit leisure suits and Nik Nik shirts.  After the crash in double-knits in the 1970s, polyester suffered from a terrible reputation. It smelled bad (especially under the arms, no kidding), was hot and had an unnatural slimy hand. Today, its different: incredibly, polyester is considered green, wicks well and is used in a wide range of garments. In fact, over the past fifteen years or so, synthetics have gobbled back the entire market share lost in the 1970s.  How on earth did this happen?

In the old days, synthetic fiber companies produced what was collectively known as “man-made fibers.” Today, this has been relabeled to read less chauvinistically as “manufactured fibers.” There are two broad segmentations in the manufactured fiber industry: synthetic and artificial fibers. The synthetic category is comprised of fibers such as polyester, nylon, acrylic, and olefin, while the artificial category is made up of acetate and rayon. Synthetics are made (in varying degrees) using petroleum-derived raw materials such as ethylene glycol, caprolactam, etc. Often times, these fibers are referred to as noncellulosic fibers – meaning they are not naturally derived. On the other hand, artificial fibers are cellulosic in that the raw materials originate in nature, such as wood pulp, but are then subjected to powerful chemicals to break down wood pulp into cellulosic cotton-like fibers.

In either case, manufactured fibers have successfully filled production niches where natural fibers do not perform particularly well. For example, polyester, nylon and rayon are used in tire cord, while acetate is used in cigar filters and olefin is used in outdoor carpets, garbage bags, and rugs. Moreover, manufactured fibers have enjoyed robust sales in various home textile and industrial applications over the years. These are versatile productts well suited to a wide range of end use applications.

From the outset of their invention, manufactured fibers have also enjoyed a sizable share of the global apparel market. Rayon, for example, was first seen as a replacement for silk; so it was widely used in womens hosiery and intimate clothing. Acetate is often used in garment linings. Polyester and nylon are often used in outerwear as both a cold weather insulator, luggage, and rain repellent covers. For many years, acrylic was used as an alternative to wool, so often acrylic was used in sweaters, but also carpets. Over the years, however, use of these fibers has expanded in apparel end uses in a blended form with cotton. Easy care shirts, for example, were first created using a 60%-40% cotton/polyester blended fabric. Cotton feels good next to the skin, but wrinkles, while polyester resists wrinkling. Many feel a blended fabric gives consumers the best of both worlds.



But these days, sustainability reigns supreme in the market. As you may know, polyester is made from the same polymer as the plastic found in soda bottles. In fact, you can melt used soda bottles to reclaim the original polymer and then extrude that to make polyester fibers – a nifty process and the basis for the green argument in favor of polyester.  After all, the goal is to use waste product that would otherwise have some awful half-life buried in a landfill.  This is the world of the so-called "circular economy."

Even so, recycled or not, the creation of synthetics fibers is a chemical process. To quote from www.madehow.com, an online reference encyclopedia, “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.” /1/



In short, polyester originates in a test tube; the same basic approach, plus or minus various chemicals, applies to other manufactured fibers. Interestingly for rayon, an artificial fiber, the process is even more complex. According to www.madehow.com:  "The major sources for natural cellulose are wood pulp—usually from pine, spruce, or hemlock trees … Sheets of purified cellulose are steeped in sodium hydroxide (caustic soda), which produces sheets of alkali cellulose. These sheets are dried, shredded into crumbs, and then aged in metal containers for 2 to 3 days. The temperature and humidity in the metal containers are carefully controlled.  After ageing, the crumbs are combined and churned with liquid carbon disulfide, which turns the mix into orange-colored crumbs known as sodium cellulose xanthate. The cellulose xanthate is bathed in caustic soda, resulting in a viscose solution that looks and feels much like honey.  Any dyes or delusterants in the design are then added. The syrupy solution is filtered for impurities and stored in vats to age, this time between 4 and 5 days. The viscose solution is next turned into strings of fibers. This is done by forcing the liquid through a spinneret, which works like a shower-head, into an acid bath. If staple fiber is to be produced, a large spinneret with large holes is used. If filament fiber is being produced, then a spinneret with smaller holes is used. In the acid bath, the acid coagulates and solidifies the filaments, now known as regenerated cellulose filaments.” /2/




So now after reading about the manufacturing processes of two of the major manufactured fibers used today, I feel like a chemist! How about you? Its curious to think that so many chemicals used to manufacture synthetic and artificial fibers actually are sold into the textile supply chain. And, indeed, these chemicals make their way to the skin of every consumer of apparel today, along with all of their properties of wrinkle and water resistance, moisture wicking, and industrial strength. This is great technology, for sure, but it is also misleads both buyers of textiles and consumers of clothing into thinking manufactured fibers are a suitable substitute for the real thing: natural fiber.

I do not wish to sound alarmist, but the chemicals used to make manufactured fibers are toxic. For example, in the case of rayon, a little history is in order:

"Known originally as the American Viscose Corporation and renamed AVTEX Fibers in July 1976, the plant was located on 440 acres on the eastern bank of the Shenandoah River in Front Royal, Virginia. Built by London-based Courtaulds Ltd., a British company, in 1937 as the largest rayon fiber manufacturing plant in the world and the largest industrial plant in Virginia, the plant was taken over by the United States Government as trade for Lend Lease during World War II. The plant made rayon fiber for garments, tires, rocket nozzles and many other uses. FMC (Food Machine Company), bought the plant in 1963 to add to their various holdings. In 1976, after letting the plant deteriorate, FMC put the plant up for sale and a manager of FMC, John N. Gregg, bought the plant for less that scrap value.

Although he spent over a million dollars for improvements to the power house and for various pollution controls, he experienced a poor rayon market, foreign competition, ageing equipment and buildings, extreme pollution, and deadly safety problems, all of which forces the company to close in November 1988. NASA had the company to reopen a few days later to make carbonized filament rayon yarn for rocket nozzles but the Virginia State Water Pollution Control Board continued to levy heavy fines for the reoccurring problem of letting chemicals reach the Shenandoah River, killing hundreds of thousands of fish. John Gregg, who had became ill with a brain tumor, sent 1300 employees home, shut the plan down for good and declared bankruptcy, leaving toxic chemicals in tanks and pipes which totally ruined much of the equipment. The Virginia Department of Emergency Services took over the plant but could not do much in saving equipment or cleaning up.

The Environmental Protection Agency had designated the AVTEX plant a Super Fund Site in 1986."  /3/

Needless to say, this is more than just a cautionary tale about poor management -- handling these chemicals can be dangerous!

Meanwhile, cotton originates in fields, the product of seeds; polyester, for example, originates in a test tube, the product of oil which comes from who knows where?  When confined to this simple comparison, which would a consumer more likely choose to have in their clothing? Granted, thats a fairly narrow comparison as there is more to the story. Polyester has often been cheaper to produce and recycle than cotton. Are those cost-savings passed on to consumers? Maybe or maybe not, but the point remains that often clothes made with polyester are cheaper than those made with cotton. Of course, then we are left with the subjective response of consumer preferences regarding cotton versus polyester: which feels better? Lets ask this guy which he prefers:



Quite a fashion statement, right? I guess he likes the water-repellent properties in his shirt. Reading this, you may feel Im taking a cheap shot at manufactured fibers. Actually, Id like to suggest that manufactured fibers have their place, but I wonder if that would change if buyers and consumers of these fibers had a better idea of what in fact they are actually buying and consuming?

Theres quite a debate these days over sustainable production. Supposedly, consumers demand sustainable or “green products. Retailers around the world have placed all sorts of demands, in turn, on the textile supply chain to find more sustainable ways of producing their products. Of course, if a retailer can satisfy their customer base while also saving a few pennies here and there, then no one is the worse for wear. Which brings me back to sustainability: which is more sustainable, cotton or polyester? Some sustainable advocates would argue that polyester is greener because it can be recycled. I disagree. Polyester has only been around since the 1940s. Cotton has been around for thousands of years. Which is more sustainable? Which is cheaper? Cotton originates in nature. Polyester originates as a product of oil. That gets me to wondering: is it possible that many manufactured fibers are actually made from oil produced by fracking? I wonder if consumers realize that?

After considering the market share for synthetic fibers, I guess consumers prefer to wear petrochemicals or is it just because it's cheap?

Notes:

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