By Patti Galvan
Wool, wood, cotton, cocoons, coal, and petroleum are natural resources used to make fabrics. The reason each of these very different things can become fabric is that they all share a common chemistry. They are all made of very long molecules called polymers. Not all polymers are good for making fabric, though. The polymers that are the building blocks of fabrics are special because they clump together to form long fibers.
For thousands of years, people have been collecting and using fibers from plants and animals to make clothes and other textiles. Even today, people collect fibers by shearing wool off animals, unraveling cocoons, and pulling soft fibers out of dried plants.
Long ago, people didn’t know about polymers, but they still figured out amazing ways to take products found in nature and turn them into cloth. Depending on the fabric and how it was made, people have used fabric to make shelters, bags, sails, bedding, and clothing!
Around the world, people use an amazing variety of physical and chemical processes on fibers found in nature. This lets them make fabrics with the properties they want, including color! Even more amazing is that many of the old techniques can still be used, on a much larger scale, to make many of the fabric products that we use daily.
There are some basic steps to using natural fibers. First, the fibers are collected and cleaned, and then they are arranged so that they all point in the same direction. Twisting the fibers together makes a strong yarn. Finally, using tools or machines, people weave or knit the yarn together to make fabric. Cotton, linen, silk, wool, cashmere, and burlap are all examples of natural fabrics.
Some people start with polymers found in nature, such as petroleum, and then use chemical reactions to build new polymers. Machines push these polymers through small holes and stretch them out to make long fibers. After that, the process is similar to the way people make fabrics from natural fibers. The fibers are twisted together to make yarn, and machines either weave or knit the yarn to make fabric. Fabrics made with fibers built by people are called synthetic fibers. Polyester, nylon, and acrylic are all synthetic fabrics.
A third category of fabric is known as semi-synthetic fabrics. The difference between these and synthetic fabrics is that the natural resource used to make the polymers in the fibers comes from wood pulp found in trees or bamboo. Unlike petroleum, trees and bamboo are renewable resources. These fibers are made the same way synthetic fibers are, by being pushed through holes and stretched. Rayon (Viscose), Lyocell (Tencel), and Modal are all semi-synthetic fabrics.
The next time you’re choosing what to wear, take a look at the tag to see what the fabric is made of. Now that you have read this article, you may recognize some of the names of the fabrics used to make your favorite clothes!
Patti Galvan is the Kids & Chemistry Program Manager at the American Chemical Society.
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