Spandex fibers were first produced by Farbenfabriken Bayer. He was a pioneer in polymer chemistry and in 1952 earned a German patent for his synthesis. The final development of spandex was produced by scientists at Du Pont and the U. S. rubber Company. Du Pont used the brand name Lycra. They soon began manufacturing in 1962. Du Pont is the world’s leader in spandex production. Spandex development first started in during World War II as a substitute for rubber. Since rubber was being used for the war effort and unstable in price an alternative would fix both problems.
First scientists’ goal was to use synthetic polymers to develop a strong strand. Around 1940 the first nylon polymers were produced by scientists at Du Pont. At first the nylon polymers were not elastic enough. Scientist soon learned that polyurethanes could be used for thread. They realized that it would make nylons more stretchable and could be used for making lightweight fabrics. The physical structure of spandex is quite simple. Spandex is a monofilament yarn or a fused multifilament yarn that is produced in an array of deniers. Because the yarn is monofilament the cross section is round.
The end use of the fabric will determine the denier of the fibers. It can range form 20 to 4300. The chemical structure is made up of stiff and flexible parts in the polymer chain. It is the size of the stiff/flexible parts that determine the amount of stretch. Spandex is made up of prepolymers and colorant. There are two types of prepolymers that contribute to spandex’s unique characteristics. Macro-glycol are long and flexible while diisocyanate are short and stronger. When the two types of prepolymers are mixed together, they interact to form the spandex fibers.
Each molecule gets added on to the end of another molecule, and a long chain polymer is formed. To initiate this reaction, a catalyst must be used. Other low molecular weight amines are added to control the molecular weight of the fibers. Spandex fibers are produced white. After production colorants are added to achieve the desired appearance. When spandex is blended with other fibers then special methods of dying are needed. Spandex fibers can be produced one of four ways; wet spinning, dry spinning, reaction spinning, melt extrusion.
These methods all use the same first step where reacting monomers to make a prepolymer. After the prepolymers are produced it is reacted in other ways to create long fibers. The method used to produce over 90% of spandex in the world is dry spinning. The quality of spandex can is controlled throughout the entire production process. Testing begins with examining the raw materials. Then testing goes on to make sure chemical and physical properties are correct and continues when appearance, color, and odor are evaluated.
By having consistent quality checks the manufacture can guarantee the quality of their spandex products. Spandex is an elastomeric fiber that is natural or synthetic. Elaostmers can be stretched to two times its original length at room temperature and then they will instantly go back to its original length. Spandex can be stretched to 500% its original length without breaking. It has poor strength but is stronger than rubber. Spandex is very resistant to body oils, perspiration, lotions and detergents.
Other properties of spandex include: lightweight, abrasion resistant, soft, smooth, supple, no static/pilling, very comfortable, and easily dyed. Spandex has a wide array of end uses. Apparel is an obvious end use. Spandex is used in apparel when stretch is desired. It is also used for comfort and fit purposes. Some examples are: swim apparel, hosiery/leggings, under garments. Compression garments such as surgical and support hose are also made of spandex. Some shaped garments are made from spandex such as bra cups. Home furnishings like micro-bead pillows are made from spandex.
Spandex is usually used in women’s apparel because their clothes are form-fitted. Most spandex in clothing is mixed in with other fibers like cotton and polyester. Spandex is a fiber that is continually evolving with the help of research. Scientists are finding ways to improve elasticity with different prepolymers ratios, catalysts, and fillers. It is also likely that advanced fabrics will have spandex blended into the fibers. Manufacturing improvements are also promising. All of these advancements will help spandex evolve.