Combing process

A.F. Filonenko. Comb. Process. Chem. Technol. Metall., Chernogolovka, 258 (1975). 

Noil noi(o)l (ca. 1624) n. A short fiber that is rejected in the combing process of yarn manufacture. 

Cotton is combed to produce finer, higher quality yams and fabrics. In 1990, 12% of the cotton processed in the United States was combed. Combing mechanically removes as much as 10-15% of the cotton as short fiber. These fibers are used in the production of lower grades of fabric. Yarns not spim from combed cotton are referred to as carded yams. Because many of the short fibers have been removed, combed yams are stronger and more uniform than carded yams. However, the combing process is expensive and adds considerably to yarn costs. 

With advances in AFM, in situ imaging has become easier and more accessible, with many techniques available for imaging the deposition of macromolecules in real time. Probably it would not be difficult to conduct a thorough in situ study of deposition kinetics on dsDNA or DNA-SWCNTs. Unfortunately, to our knowledge such a study has not been undertaken. One reason is that perhaps the final density of objects observed on the surface after molecular combing is reduced by the combing process, and it is more relevant to... 

The compression of the fiber material demands an intensive fixing of combs. Process interruption and damaging of fibers are the consequence. 

A wool combing plant typically comprises the following processes ... 

Combing is thus a critical process in producing a quaUty top. It is also a costiy process, and a modem comb wiU only produce at a maximum rate of about 30 kg/h for 21 p.m wool. 

Processes 8 and 9 again employ giUs. The purpose is to shuffle the fibers in the combed sUvet to produce a random positional distribution, and thus the most even sUvet possible. The second finisher gilling wiU also incorporate either a baU winding head, or a press that condenses top that has been deUveted into a can. This latter product is caUed bump top. Both baU and bump facUities ate usuaUy necessary to satisfy customers differing needs. Bumps or baUs wUl then be further pressed into bales for shipment. Combed wool destined for processing on the woolen system may be sucked in short lengths from the comb to form broken top. 

Some combing plants also produce shrink-resistant treated wool-top. The current process incorporates chlorination, and the appHcation of a shrinkproofing polymer. Chlorination is likely to be replaced soon by mote environmentally friendly treatments. 

Anionic grafting methods (vide infra) can be applied to the synthesis of comb-shaped polymers. As an example, a polystyrene backbone is partially chloromethylated (under mild conditions) and used as an electrophilic deactivator for a living polystyrene 89). The grafting onto process yields well defined species that have been characterized accurately. The branches are distributed randomly along the backbone 90). 

Injection molding is a common process that we use to convert polymer granules to solid objects. Unlike the products made by continuous extrusion processes, discussed in Chapter 11, products made by injection molding are discrete objects, produced in individual mold cavities. We encounter injection molded products of all sorts in our daily lives, ranging from combs, bottle caps, and ballpoint pens to car steering wheels, camera bodies, and the keys on our computers. 

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