An understanding of the basics of cotton yarn in textile production.
Cotton fiber is a thread-like substance, called “Staple". Grown in warm drier climates, cotton requires 4-5 months of 60°F - 86°F weather. Although the textile industry has migrated east, The U.S. cotton industry still thrives, ranking third behind China and India.
The length of staples determines the quality of cotton. The higher the length, the better the cotton is. Staple length can vary from .375” to 2.25” depending on variety and growing location (temperature, fertility, and water stress all affect the length of the staple).
Types of Cotton
There are four main varieties of cotton:
Sea Island Cotton - it is the best quality of cotton in the world and it has the longest staple of 2.25”. Sea Island Cotton is mainly grown in South Carolina, Georgia, Florida and islands off the coast of these states. Sea Island Cotton is frost-sensitive and thrives in tropical areas with high humidity.
Pima Cotton – is related to Sea Island and Egyptian cotton adapted to grow in more arid climates through a partnership between the U.S. Department of Agriculture and Pima Tribe Native Americans. USDA named the cotton after the Pima Tribe to honor the collaboration.
U.S. Cotton – has 3rd largest staple length and is grown in U.S. other than the states where Sea Island cotton grows. The staple length varies but may reach maximum 1.5”
Asian Cotton – is grown in Asia like India, Pakistan, Japan, and China. The most common variety of cotton with a maximum staple length of 1.125”.
The thickness of the cotton staple is the other determinant of cotton quality. Finer longer staples yield higher quality yarn as slim long staples can be spun together to create finer, stronger cloth.
Preparing for Yarn Spinning
You must prepare the staples for spinning into yarn by removing foreign objects, separating usable staples, and aligning the remaining staples. The resultant "sliver" is achieved through a process of combing or carding.
Higher quality staples are 'combed' through a series of metal teeth that lay the staples parallel to each other. This is a more expensive process as combing cotton will save only the finer, long staples for processing.
Shorter staple cotton must be carded (to survive the process). Cards with wire teeth are used to separate the staples from the detritus however they are not laid parallel.
Cotton uses a unique measurement system to classify yarn quality. You'll see numbers like 10/1, 16/1, 20/2 e.t.c., but what are they? and how they are determined?
If you take 1 strand of yarn of and 840 YDS (1 YD = 0.9144 Meter) of same and if this 840 yds weigh 1 lb, then we can call this 1s yarn. While seemingly a random number, 840 yards is the distance that 1s cotton occupies to weigh 1Bb, therefore all other measurements must use 840 yards and 1Lb as controls.
For example, take 2 strands of yarn each 840 yds in length and both together weigh 1lb, then we call this 2s yarn. Twice the yarn weighs the same. As mentioned, the finer the yarn, the better quality the textile.
Theoretically in the textile industry, one can make yarn from 4 count to 120 count. The higher the number of counts the finer the yarn is. Normally in towel business we work with 10S up to 30s with 12s and 16s being the most common. Higher numbers are usually used for making finer fabrics.