Spandex

DuPont textiles scientist Joseph C. Shivers was determined to find a fiber to replace rubber in garments. He made a breakthrough in the early 1950s when he used an intermediate substance to modify Dacron polyester.[8] This modification produced a stretchy fiber that could withstand high temperatures. After nearly a decade of research the fiber was perfected in 1959. Originally called Fiber K, DuPont chose the trade name Lycra to distinguish its brand of spandex fiber.[9]

Spandex fibers under an optical microscope (cross-polarized light illumination, magnification 100x)

Spandex fiber

Spandex fibers are produced in four ways: melt extrusion, reaction spinning, solution dry spinning, and solution wet spinning. All of these methods include the initial step of reacting monomers to produce a prepolymer. Once the prepolymer is formed, it is reacted further in various ways and drawn out to make the fibers.

The solution dry spinning method is used to produce over 94.5% of the world's spandex fibers,[10] and the process has five steps:

• 1. The first step is to produce the prepolymer. This is done by mixing a macroglycol with a diisocyanate monomer. The two compounds are mixed in a reaction vessel to produce a prepolymer. A typical ratio of glycol to diisocyanate is 1:2.[10]
• 2. The prepolymer is further reacted with an equal amount of diamine. This reaction is known as chain extension reaction. The resulting solution is diluted with a solvent (DMAc) to produce the spinning solution. The solvent helps make the solution thinner and more easily handled, and then it can be pumped into the fiber production cell.
• 3. The spinning solution is pumped into a cylindrical spinning cell where it is cured and converted into fibers. In this cell, the polymer solution is forced through a metal plate called a spinneret. This causes the solution to be aligned in strands of liquid polymer. As the strands pass through the cell, they are heated in the presence of a nitrogen and solvent gas. This process causes the liquid polymer to react chemically and form solid strands.[10]
• 4. As the fibers exit the cell, an amount of solid strands are bundled together to produce the desired thickness. Each fiber of spandex is made up of many smaller individual fibers that adhere to one another because of the natural stickiness of their surface.[10]
• 5. The resulting fibers are then treated with a finishing agent which can be magnesium stearate or a polymer. This treatment prevents the fibers' sticking together and aids in textile manufacture. The fibers are then transferred through a series of rollers onto a spool.

Cyclist wearing a pair of spandex shorts and a cycling jersey

French Ski team (2010) wearing Spandex.

In the post World War II era, DuPont Textiles Fibers Department, which was formed in 1952, became its most popular division, dominating the synthetic fiber market worldwide.[11] At this time, women began to emerge as a significant group of consumers because of their need for underwear and hosiery.[11] DuPont conducted market research to find out what women wanted from textiles, then began developing fibers to meet their needs, including a better fiber for women's girdles, which were commonly made of rubber at the time. DuPont became interested in developing a synthetic elastic fiber in the 1930s, which was perfected by chemist Joseph Shivers in 1959. Spandex's transformative nature allowed it to be incorporated into other garments besides girdles and undergarments. DuPont launched an extensive publicity campaign for its Lycra brand, taking advertisements and full-page ads in top women's magazines such as Vogue, Glamour, Harper's Bazaar, Mademoiselle, McCalls, Ladies Home Journal, and Good Housekeeping.[11] Fashion's original style icon, Audrey Hepburn helped catapult the brand on and off-screen in the late 1950s; models and actress like Joan Collins and Anne-Margret followed Hepburns aesthetic by posing in Lycra clothing for photo shoots and magazine covers.[12]

By the mid-1970s, girdle sales began to drop with the emergence of the Women's Liberation Movement. Girdles came to be associated with anti-independence and emblematic of an era that was quickly passing away.[11] DuPont was not ready to abandon a market that they were significantly reliant on. In response, DuPont reimagined Lycra as the aerobic fitness movement emerged in the 1970s.[11] This expansion furthered at the 1968 Winter Olympic Games when the French ski team wore Lycra garments to compete.[13] This popularized the brand as essential athletic wear because of its flexible and lightweight material. The fiber proved to be especially popular in mid-thigh-length shorts worn by cyclists.[13] By the 1980s, the fitness trend had reached its height in popularity and fashionistas began wearing shorts on the street.[14] Spandex proved such a popular fiber in the garment industry that by 1987 DuPont had trouble meeting worldwide demand. In the 1990s a variety of other items made with Spandex proved popular, including a successful line of body-shaping foundation garments sold under the trade name Bodyslimmers. As the decade progressed, shirts, pants, dresses, and even shoes were being made with spandex blends, and mass-market retailers like Banana Republic were using it for menswear.[14]

The elasticity and strength (stretching up to five times its length), of spandex has been incorporated into a wide range of garments, especially in skin-tight garments. A benefit of spandex is its significant strength and elasticity and its ability to return to the original shape after stretching and faster drying than ordinary fabrics. For clothing, spandex is usually mixed with cotton or polyester, and accounts for a small percentage of the final fabric, which therefore retains most of the look and feel of the other fibers. In North America it is rare in men's clothing, but prevalent in women's. An estimated 80% of clothing sold in the United States contained spandex in 2010.[15]

A human pyramid of dancers wearing spandex zentai suits

The types of garments which incorporate spandex include:

• Accessories
  • Belts
  • Gloves
  • Socks
  • Tights
• Athletics
  • Competitive swimwear
  • Cycling jersey and shorts
  • Exercise apparel
• Bodysuits
  • Leotards
  • Rowing unisuits
  • Triathlon suits
  • Wetsuits
  • Zentai suits
• 

  Woman wearing spandex leggings
  Bottoms/Pants
  • Leggings
  • Shorts
  • Skinny jeans
  • Ski pants
  • Slacks
  • Yoga pants
• Compression garments
  • Foundation garments
  • Motion capture suits
• Shaped undergarments
  • Bras/side paneling
  • Hosiery
  • Support hose
  • Surgical hose
  • Swimwear
  • Underwear

Today most clothes containing spandex end up as non-recyclable waste once they have been worn out, as fabric blends containing spandex are difficult to recycle.[16] This contributes to the pollution of the environment.

When clothes are washed, hundreds of thousands of microfibres are released into the wastewater, ending up in the oceans, and if clothes contain plastic then they will cause microplastic pollution.[17]

• Athleisure
• Darlexx
• Gym shorts
• Leotard
• Spandex fetishism
• Yoga pants
• Natural rubber

Wikimedia Commons has media related to Spandex.

• "What's That Stuff: Spandex" Chemical and Engineering News