The long, thin materials that make up textile fibers are formed by small molecules linked together in long chains. These are called polymers, and we refer to them as fibers.

The chemical process of linking these small molecules into long chains is called polymerization. Plants create polymers by polymerizing glucose molecules, and this substance is called cellulose.

Cellulose makes up most of the structural material of plants. Cotton plants and cotton fiber are composed of more than 90% cellulose, and this is what we call cotton.

Cotton is an annual plant, and its seeds are sown each year in April and May.
About two weeks after planting, the cotton sprouts emerge. In July and August, yellow cotton flowers bloom, and after the flowers fall, the cotton bolls remain. When the bolls are fully mature, they split open and white cotton fibers burst out. To maintain good quality, this cotton should be harvested before frost.

The fluffy mass obtained from cotton is called seed cotton, and the process of removing the seeds from seed cotton is called ginning. The seedless cotton fiber is called lint, while the short fibers attached to the cottonseed are called linters. Linters are used as a raw material for regenerated fibers.

The raw cotton is first opened up and cleaned to remove impurities. Different cotton fibers are then blended together and formed into a loose, blanket-like strand called a sliver. This sliver is further combed and given a slight twist to make it finer. It is then twisted further and subjected to the final drafting process, through which the yarn is produced.

In their natural state, cotton fibers are arranged in many different directions. To use them as yarn, they must be carded so that the fibers are aligned in a single direction. This process is what we call carding.

As cotton fibers, which were originally tangled in various directions, become increasingly parallel and well aligned, the friction that held the fibers together decreases. As a result, the fibers can no longer hold together on their own and cannot form yarn.

The process that restores this lost binding force—by giving the fibers the ability to grip one another—is twist.

Carding

A carding machine is similar to a cotton-fielding machine with fine needles set on the surface of rotating cylinders. As the cotton passes through these cylinders, it is brushed and opened.

After the carding process, the fibers are still too short and uneven to become finished yarn right away. The main purpose of carding is to align the cotton fibers in one direction. For lower-grade yarns, the material may move directly from carding to the drawing process after this single brushing stage.

Combing

Combing is a process in which the cotton passes through cylinders with finer, denser, and more closely arranged combing needles than those used in carding.

Yarn that goes through the combing process after carding is mainly used to produce higher-quality products. Because it contains fewer impurities, it has better luster, better dyeability, and a smoother hand feel.