Cotton Fiber Selection

Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plants of the genus Gossypium in the mallow family Malvaceae. The fiber is almost pure cellulose, and can contain minor percentages of waxes, fats, pectins, and water. 

No matter the desired end result, proper fiber selection is the foundation of any successful spinning operation. With just over fifty percent of operation costs being required for raw material, it is very clear the importance of decisions made towards that end. In any spinning operation, the requirements of the end product, or of the consumer of the yarn, will be the dictating forces in determining the fiber quality and properties that are best suited for the most economic situation. Using fiber that is of better quality than required will prove unprofitable. Likewise, using fiber that is of poorer quality than required will result in losses as well. Most mills then find themselves in the precarious position of following a very narrow path of success where fiber quality is concerned. Correct decisions regarding the most suitable fiber properties for a given operation are paramount for maintaining profitability. In any spinning operation, the requirements of the end product, or of the consumer of the yarn, will be the dictating forces in determining the fiber quality and properties that are best suited for the most economic situation. 

Using fiber that is of better quality than required will prove unprofitable. Likewise, using fiber that is of poorer quality than required will result in losses as well. Most mills then find themselves in the precarious position of following a very narrow path of success where fiber quality is concerned. Correct decisions regarding the most suitable fiber properties for a given operation are paramount for maintaining profitability. As is evidenced by the adjoining table, specific fiber properties vary in their importance according to the spinning system employed. These differences in importance are due to the mechanical design of the particular spinning system and the physics involved. 

Ranking these properties in no way means that the lowest-ranked property is not to be considered. It simply displays the importance of the individual fiber properties for good spinning performance. From a yarn manufacturing standpoint, these are the usual criteria for making fiber purchases. For instance: Fiber length is more important to ring spinning than it is to rotor spinning in order to achieve acceptable results in the spinning mill. It should also be pointed out that with significant movement in yarn count, either towards the extreme coarse or fine side, some of these relationships may shift. The main consideration for all the spinning systems, as yarn count moves to the fine side, is fiber fineness (lower micronaire). This is due to the necessity of maintaining a sufficient number of fibers per cross-section in the yarn. Yarn end-use may also dictate the choice of fiber properties and their ranked importance. Weaving yarns typically are required to be stronger and have higher tensile values than their knitting counterparts. This places more emphasis on the ultimate strength of the yarn and not just on its spinning performance.