Combing - Yarn Spinning, Fiber Preparation Process

Combing process is done for removing short fibers, neps and impurities from cotton. Combing is carried out in order to improve the quality. Combing removes short fibers from the yarn-making process. Depending on the cotton fiber being combed, and the settings of the comber itself, short can have more than one meaning, but generally, it means fibers that are half an inch or less in length. The percentage of these fibers removed can vary greatly, again, depending on the cotton being used and the settings of the comber. The combing process starts by preparing what is known as a lap. This is simply a number of individual, once-drawn slivers that are wound in a ribbon-like fashion onto a spool. This wound lap becomes the input for the combing process. 

For each combing cycle, a measured amount of the lap is fed out and held fast for the pass of the half-lap. The half-lap is a wire or needle-covered section mounted on a rotating shaft that passes its teeth or needles through the held beard - the measured lap that has been fed out and held fast. The fibers that are not held fast are removed by the half-lap and collected as waste. These short fibers may be recycled and used elsewhere in a less critical yarn. The combed webs are condensed back into sliver and coiled into a can for temporary storage and transport to subsequent processing. The reasons for combing vary greatly depending on the end product but generally, it is done to increase the yarn count range of the material being processed. A finer yarn can be made from combed cotton which tends to result in an end product with extra sheen, drape, and hand. Combed yarns and the resulting products tend to be softer and yield more durability. From an engineering standpoint, combing may be required for some yarn counts and some end product performance standards. For other end products, it may just be a price point decision.