Spandex is a synthetic elastic fiber that can be stretched to almost 500% of its length and then recoils back to its original shape. It is a much more robust and lighter material than rubber, making it ideal for clothing use.
Pre-polymers are reacted to create the fiber’s skeleton in spandex production. Pre-polymers come in two different varieties: diisocyanate and macro glycol.
The Pre-Polymer
Spandex is a synthetic fiber that is used in garments that need elasticity. It is commonly found in sportswear and undergarments, such as support hoses, bras and briefs.
To make the fabric like black spandex fabric, use a process called pre-polymerization to create the initial structure of the material. Under particular temperature and pressure conditions, a substance known as macro glycol is combined with a diisocyanate monomer to achieve this. If the conditions are perfect, then a pre-polymer is formed.
After the pre-polymer is created, it is exposed to a chemical known as diamine acid. This reaction causes the pre-polymer to form a long-chain polymer.
Next, a chain extender is added, a molecule that adds strength to the polyurethane. This molecule is typically made from hydrazine or ethylene.
The chain extender molecule binds with the hard and soft segments of the elastomer, which provide sites for hydrogen bonding. It also adds tensile strength to the molecule and limits plastic flow.
Another elastomer component is diisocyanate, a smaller molecular weight molecule that acts as a coupling agent for both the macro glycol and the chain extender components. This molecule has symmetrical and cyclic nuclei, which helps it produce the hard and soft segments of the urethane that are necessary for spandex fiber to be elastic.
The Stabilizers
The stabilizers that are used to make spandex are made of different chemicals. These substances are added to the pre-polymers and other raw materials used to make the fabric. The stabilizers are designed to protect the fiber from damage.
Stabilizers can be made from various materials, but most are made of polyurethane or synthetic rubber. They are added to fabrics to make them stiffer and keep the pieces of the fabric together when sewn.
Spandex is a type of synthetic material that has a unique elastic property. It can be stretched to almost 500% of its length and then recovers close to its original shape. This flexible ability makes it an excellent fabric for making clothing because it has a high level of comfort and fits well without bagging or sagging.
To make spandex, a mixture of macro glycol and diisocyanate is heated and pressured to create a pre-polymer. The pre-polymer is then exposed to a chemical reaction that causes it to form a polymer called elastane.
After the elastane is formed, it’s treated with various stabilizers that help the fibers withstand wear and tear. They also help to prevent discoloration from exposure to harmful substances like combustion fumes or smog atmosphere.
Stabilizers can be added to the fabric during sewing or sewn at seams. The sew-in option is usually better because the glue can wear down over time.
The Spinning Process
Spandex is a stretchy synthetic fiber that is used in a variety of fabrics for different applications. It is a popular material for clothing because it can withstand abrasion and improve the drape and movement of the fabric. The amount and type of spandex used in the fabric are determined by its end use, such as swimwear or active sportswear. It is often blended with natural or artificial fibers and may be woven or knitted into the fabric.
The elastomeric property of spandex is a result of its unique structure. It comprises “soft” and “hard” bonded segments. The delicate details allow the fiber to stretch four to seven times its original length but then spring back to its initial size after removing tensile stress. This elasticity is unlike rubber or other elastomeric materials that lose their elasticity after repeated stretching.
Various raw materials are used to produce spandex, including pre-polymers and stabilizers. The pre-polymers are reacted in multiple ways to create long spandex fibers, and the stabilizers provide strength to the fabric.
The Finishing Agent
Magnesium stearate or poly(dimethyl-siloxane) is the finishing agent used to make spandex. This material prevents the fibers from sticking together and aids in textile manufacture. It is usually applied to the fabric during production and cured before spinning to give the finished product its desired look.
Spandex is a synthetic fabric with a wide range of applications in the fashion industry. It is most widely known for being used in men’s suits, athletic clothing, bed linens, and shoes, but it also has many other uses.
Unlike other synthetic fabrics, spandex has no organic components, so it is produced entirely in the laboratory. In the production process, macro glycol is mixed with a diisocyanate monomer under precise temperature and pressure conditions.
When the two compounds are combined, a pre-polymer contains an equal percentage of each component material. The ratio of glycol to diisocyanate must be a precise value for the product to be effective.
The pre-polymer is then exposed to diamine acid, and a chemical reaction causes the material to expand. As the amorphous segments grow, they bond with the rigid details to form an elongated fiber that is stiffer and stronger.
This process is referred to as solution dry spinning, and it is used to make nearly 95 percent of all elastane in the world. There are other methods for producing elastane, but these tend to be less efficient than solution dry spinning.
