Spandex is a synthetic fabric prized for its elasticity. Contrary to popular belief, the term "spandex" is not a brand name, and the term is often used to refer to polyether-polyurea copolymer fabrics made using various production processes. The terms spandex, lycra, and elastane are synonymous. This fabric can be stretched to 5-8 times its normal size and is commonly used in next-to-body clothing. In most cases, pure spandex is not used in clothing, but small amounts of this fabric are woven into other synthetic, semi-synthetic, or organic fibers.
Like other polymers, spandex is made of repeating chains of monomers bound together with acid. Early in the spandex development process, it was recognized that the material had a high heat resistance, which meant that notoriously heat-sensitive fabrics like nylon and polyester improved when combined with spandex fabrics.
The elasticity of elastane immediately made it popular around the world, and the popularity of this fabric continues to this day. It's found in so many types of clothing that nearly every consumer owns at least one garment that contains spandex, and it's unlikely the fabric's popularity will decline in the near future. Unfortunately, however, spandex has had a significant detrimental impact on the environment since it entered the consumer market.
Since spandex is a fully synthetic fiber, no organic ingredients are used to create the material. Instead, all of the fiber's components were created in a laboratory setting and then combined under specific stimuli to create spandex fabrics. In the years since the invention of elastane, many different methods of making this fabric have emerged.
Some of these methods are more efficient than others, and methods such as reaction spinning, melt extrusion, and solution wet spinning have mostly been abandoned over time. Nearly 95 percent of the world's spandex is now made using a method called solution dry spinning. To begin the spandex fabric production process, a substance called polyethylene glycol is mixed with diisocyanate monomers under specific heat and pressure.
The temperature and pressure conditions must be precise to produce the desired results, and the ratio of polyethylene glycol to diisocyanate monomers must be close to 1:2. If the right conditions are applied, a substance called a prepolymer is formed, which is then used in the rest of the manufacturing process. Once formed, the prepolymer is exposed to the diamine and initiates a chemical reaction called chain extrusion.