Textile Combing Machine

Overview

A combing machine removes the short fibers from cotton so the mill can spin fine, smooth, strong yarn. Carding cleans and aligns the fiber but leaves the full range of fiber lengths in the sliver, including short fibers that add no strength and make the yarn hairy and weak. Combing pulls those short fibers out, along with any neps and trash the card missed, and leaves only the longer fibers laid parallel. The waste it takes out is called noil, and a mill can comb out anywhere from eight to twenty-two percent of the feed depending on how fine and clean the target yarn is.

Combed yarn is the basis of high-count shirting, fine knitwear and sewing thread. The process costs fiber and adds a machine to the line, so coarse yarns are spun carded, without combing. The machine works in a repeating cycle rather than continuously: it grips a tuft, combs it, draws it off and joins it to the last, hundreds of times a minute across eight heads working in parallel.

Feeding the lap

The comber does not feed from sliver. Ahead of it a lap former winds several drawn slivers into a flat compact sheet called a lap, and the Lap Feed & Creel station holds these laps and unrolls each one into its combing head. A Feed Roller pushes a small measured length of lap forward before each combing stroke, and a Feed Advance Pawl ratchet sets exactly how much, which is one of the levers on combing quality: a shorter feed combs each length more thoroughly and takes more noil.

The combing cycle

The work happens in the Combing Head, and the sequence is the heart of the machine. First the Nipper Plate Assembly clamps the fed lap firmly by its rear, leaving a fringe of fiber hanging free in front of the jaw. Then the Circular Comb Cylinder, a rotating cylinder carrying a Comb Needle Segment of graded needles, sweeps through that hanging fringe. Because the fiber is held at the root, the comb can only drag out fibers shorter than the held length, plus any loose trash and neps, while the long fibers stay anchored. That extracted material is the noil.

The nipper then opens and the cleaned fringe is presented forward. As it is drawn off, the Top Comb drops into the fiber and cleans the leading end too, catching short fibers and trash that the circular comb at the root could not reach. So each tuft is combed from both ends across the cycle.

Detaching and piecing

Because the lap is fed and combed in steps, the combed fiber comes off in separate tufts, not a continuous strand. The Detaching & Piecing rollers turn this back into a continuous web. They draw each freshly combed tuft forward and, timed by the Detaching Motion Cam, lay it overlapping the tail of the previous tuft on the Piecing Support Plate. The overlap, called the piecing, hides the join so the web has no thin spot where one tuft meets the next. Getting the piecing even is what separates a good comber setting from a bad one, since a regular piecing fault shows up as periodic unevenness in the yarn.

Forming the sliver

The eight heads each deliver a thin combed web, and these run forward on the Web Table & Draft, where they are gathered side by side, drafted a final time and drawn together through a trumpet into a single round sliver. Calender rollers compact it and the Sliver Coiler lays it into a can in even coils, the same end stage a draw frame uses, ready for the next drawing passage or the roving frame.

Noil removal

Removing the noil cleanly is essential, since it is the whole purpose of the machine. The Noil Suction System system pulls the combed-out short fibers off the circular comb each stroke, with a Comb Cleaning Brush brush wiping the needles clear so they keep combing. The noil from all heads collects in a box, and its weight against the lap fed gives the comb percentage, a number the mill controls tightly because it sets both the yarn quality and the fiber loss.

Drive, materials and use

The nipper, feed and detaching motions are all driven from a Main Camshaft so they stay in fixed phase, while servo drives handle the table draft and coiler. The Machine Control sets comb speed, feed and noil level and logs comb percentage and production. The base and head castings are cast iron to absorb the impact of the nipper striking hundreds of times a minute. The comb needles are hardened steel, replaced as a segment when they dull. Combing sits between the lap former and the finisher draw frame in the comber line, and it is the step that defines whether a mill can sell into the combed-yarn market at all.