Combing

Combing is a method for preparing carded fiber for spinning. It separates out the short fibers by means of a rotating ring or retalinear 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.

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 slowelly 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 to comb out the fringe and remove short fiber (set by a scale so fibers less than for example 25mm are removed ) not held by a clamping mechanism. The Top comb is a very fine tooth comb for example 25teeth per inch to act as an impediment to contaminates (Burr, seed ect.) flow. The circular combing without shot fibers are placed on a moving belt. The of 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( 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. Woolen 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.

In general, combing is done to remove the short length fibers. For example fiber shorter then 21 mm. The comb is a filter or sieve for short fiber length worsted. In process of combing carding is a primary process followed by 3 gilling machining. The gilling process is there to remove hooks and involves 3 separate machines. Combing removes short fiber content as sated earlier. The Combing is than followed by 2 gillings to remove irregularity in the sliver and randomize fiber ends. This post combing process is required if spinning is to follow. It is know that a sliver can be spun to a yarn of only 21 fibers with a suitable average length of say 150mm (CSIRO 1990).

Combing is a mechanical sieve and will not remove any containment that looks like a fiber being combed. That has to be mended out from a final garment. The manual mending out is a costly process.

There are two competing combing technology - Noble (1853) Comb ( variants Lister, Heilman (1846) and Holden) and French Comb. Noble comb technology is inefficient hence most combing in world is carried out on French system. The French system is superior as it combs' and entire length of a fiber. Noble comb suffers from a problem that it will not comb 2mm of a fiber length. The 2mm is distance between counter rotating pins. The French system is a rectilinear combing system as oppose to earlier woollen system developed in England. Although Heilman and Noble comb was original circular design ( also developed in min and 18-19th century England ) as it happens in modern history, English mills didn't share technology - resulting in development of superior technology on the continental Europe in mid 19th century- France. 

Efforts was made by Bradford to study the mechanism of noble combing but it failed to produce tangible results..The Noble and French combs are now well understood technology thanks to work by CSIRO. Post 1994 Sokolov has endeavored to improve combing performance in rectilinear comb. Post 20th century effort in combing technology.

Machinery

In cotton manufacture, the Heilmann comber was superseded by the Naismith comber. In worsted a Noble comber was a common make.

Noble comb is no longer used in worsted system as technology is inefficient. Noble comb may have uses for woolen system or long fibers 250mm+. Predominate technology for all fibers is a French Comb system. A cotton comber is scaled version of a rectilinear comb relative to a mean fiber length (similar to Naismith comber). This can scaled version can be seen in stroke of the components to accommodate fiber length and fiber physics needs.

will add more to this topic soon with mechanics and sketch of processing .