Gilling (textiles)

Combing is a method for preparing carded fiber for spinning. Combing is divided into linear and circular combing. The Noble comb is an example of circular combing. The French comb is an example of linear combing. The process of combing is accompanied by gilling, a process of evening out carded or combed top making it suitable for spinning. Combing separates out short fibers by means of a rotating ring or rectilinear row of steel pins. The fibers in the 'top' it produces have been straightened and lie parallel to each other. When combing wool, the discarded short fibers are called noils, and are ground up into shoddy.

In general there are two main systems of preparing fiber for yarn: the worsted system and the woollen system. The worsted system is defined by the removal of short fibers by combing and top preparation by gilling. In the woollen system short fibers are retained, and it may or may not involve combing.

The circular combs used have long metal teeth, and only barely resemble the comb used on hair. However, they are used in a similar fashion with one comb holding the fiber, which is slowly dubbed in by a brush, while the other is moved through, slowly transferring the fiber to the moving comb.

The rectilinear comb uses a circular comb mounted on a drum to comb out the fringe and remove short fiber (set by a scale so fibers less than, for example, 25 mm are removed) not held by a clamping mechanism. The row of pins known as a top comb is a very fine tooth comb, for example 25 teeth per inch; it is inserted in cylindrical combed fringe to act as an impediment to contaminates (burr, seed etc.) flow. The top comb acts as an impediment to contamination moving into a combed sliver. On a next circular combing short finer and contaminates are removed. The circular combing without short fibers are placed on a moving belt in an overlapping motion. The circular combing and top comb insertion is repeated and combed fibers - now called tuft are overlapped. The overlapping produces some cohesion allowing the tuft then to be twisted to form a combed sliver. This sliver is weak and unsuitable for spinning. To allow spinning to take place additional gilling is required to introduce fiber end irregularity (Sokolov 1994).

Combing the fibers removes the short fibers and arranges the fiber in a flat bundle, with all the fibers going the same direction. This preparation is commonly used to spin a worsted yarn. Woollen yarns cannot be spun from fiber prepared with combs, instead the fiber must be carded. Cotton is combed when it is to be used for quality fabric with high thread counts.

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