How Is Cotton Cloth Made?

Varieties of Cotton Cloth

Varieties of cotton cloth include denim, chambray, terrycloth, twill, seersucker and corduroy. All are made using the same basic process: the fibers of a cotton plant are harvested and spun into threads which are then woven into cloth.

Growing Cotton

The cotton plant is a member of the mallow family, native to tropical and subtropical parts of the world. Cotton-producing nations include China, India, the United States, Pakistan, Brazil and Uzbekistan. As a vegetable fiber, cotton's main ingredient is cellulose. When the flowers of a cotton plant have blossomed and withered, they fall and leave spherical green seed capsules called cotton bolls. As cotton bolls ripen in the sun, their fibers expand, fluff up and burst out.

Harvesting Cotton

In the United States, cotton is now entirely machine harvested, but it is still handpicked in some developing countries. Cotton is harvested using either a mechanical cotton picker that removes cotton from the boll with a twisting motion, or a cotton stripper that removes the entire boll. Harvested cotton bolls are stored in large blocks called modules. These modules are then transported to a cotton gin.

Ginning Cotton

A cotton gin separates cotton fibers from seedpods and seeds. The raw cotton is first moved through cleaners and dryers to remove dirt, leaves and stems from the cotton field. The gin then moves the cotton through a grid of fine combs which brush the fibers straight while removing the cotton seeds. The ginned fiber is called lint. Lint is pressed into solid bales weighing up to 500 lbs. Samples of the lint are examined to determine the price of the cotton--which is based upon length of the fibers (staple), strength, color and cleanliness. The lint is usually sold to a third party who will send it to a textile mill to be made into cloth.

Spinning Cotton into Thread

Cotton is often imported from cotton-growing nations to nations with textile manufacturing infrastructure such as Bangladesh, Indonesia, Russia and Thailand. At textile mills, bales of lint are cleaned by mechanically blowing the fibers. The lint is then separated by fiber length; shorter-lint fibers are sent elsewhere to make paper and other products. Lint with fibers that are at least 1 inch long are used to make fabric. Fluffed up, longer cotton goes into a carding machine that further cleans the fibers and aligns them with a combing action. A soft, untwisted rope called a sliver comes out of the carding machine.
Cotton has been spun using essentially the same technique for centuries. Spinning frames draw out fibers from the sliver and rapidly twist and wind them, forming a thin thread or yarn. The resulting threads and yarns have different qualities that depend on the length of cotton fiber, and by the degree, tightness and direction of the twist. Cotton threads are sold as sewing thread or woven into cloth. Cotton yarns are sold for knitting and crocheting, or made into knitted fabric by machines.

Weaving Cloth

Cotton threads are woven into fabric on looms. Looms are machines that work at high speeds to interlace horizontal and vertical sets of threads to form a flat cloth.
A set of parallel warp (vertical) threads are held taut by the loom. Filling or weft (horizontal) threads are held by bobbins that are placed in a shuttle. The loom lifts the warp threads up and down in sequence, creating a space between them for the shuttle to pass through at high speeds. This action weaves the two sets of threads together at right angles and creates a strong fabric. There are three main types of weave: plain, satin and twill. The different weave structures are created by changing the sequence of raising and lowering the warp threads. Different types of cotton cloth are made by changing the density of the weave, the colors of thread used for warp and weft, and the number of threads used per inch of fabric.
Other types of machines make knit fabrics from cotton yarns.

Resources

• The Cotton Council of America