Combing

COMBING

This term is used literally and denotes the combing of fibrous materials in sliver form by mechanically actuated combs, or by hand-operated combs. In general, the objects in combing are two, namely (1) to obtain the maximum parallelisation of the fibres, and (2) to remove impurities and undesired short fibres. Combing machines differ considerably in their action on fibres, and in practice the different types of combs are used in somewhat restricted fields. For combing cotton the Nasmith and Heilmann combs are principally used. In the United States of America the Whitin comb is much used. In all three of these machines successive rows of combs are set in cylinders, the material being presented for combing in the form of thin narrow laps, which after combing are formed into a sliver and coiled in a can. For combing wool, four types of comb are in use, namely, the Noble, Lister, Holden and Heilmann. Also see under each name. The combs of the Noble machine are in the form of pins set vertically in one large and two small circles with appropriate mechanism for dabbing the wool into the pins of the combs and means for drawing off the combed wool in a continuous sliver, which is wound into a ball and constitutes the " top " of the worsted trade. The machine has a high production and is suitable for use on a large variety of wools, particularly those of 4-in. to 8-in. staple. The Lister comb is specially suitable for long wools. The combing mechanism includes a gill-box and comb circle. The Holden comb is suitable for wools of 3-in. to 6-in. staple, and of 50's to 70's quality. The Heilmann, also known as the " rectilinear " comb, is used for short wools, say, up to about 2-in. staple, and when used for wool is arranged differently for feed and delivery than for combing cotton. It is becoming of increasing importance for combing short fibred wools for subsequent spinning into fine, full handling hosiery yarns.