Combing Machine

Overview

A combing machine refines carded sliver into the smooth, strong, lustrous stock used for fine and high-quality yarns. Carding parallels the fibre and removes the worst trash, but a carded sliver still holds a large fraction of short fibre, plus hooks and small neps. Combing removes the short fibre as a measured "noil" and straightens the rest, so the combed sliver contains only long, parallel fibres. Yarn spun from it is finer, stronger, more even and far less hairy, at the cost of throwing away some of the stock as noil.

Unlike carding, combing is a cyclic, intermittent process rather than a continuous one. The machine grips a small tuft, combs its front and back, joins it to the previous tuft, and repeats hundreds of times a minute across eight heads working in parallel. The art is to comb out the short fibre without pulling the good long fibre through, which is why the fringe is always clamped while it is combed.

How it works

Each cycle begins at the Lap Feed & Nipper, where lap rollers meter a wadding forward and the nipper clamps the leading fringe of fibre against its cushion plate. With the fringe held, the Circular & Top Combs go to work: the circular comb, a part-round needle roller, sweeps through the projecting fringe and combs out everything not gripped, while a moment later the top comb drops into the rear of the tuft as it is drawn off, cleaning the part the circular comb could not reach.

The Detaching Rollers rollers then draw the cleaned tuft forward and reverse to overlap it onto the tail of the previous one, piecing the separate tufts into a continuous web. The webs from all eight heads meet at the Web Piecing table, where a condenser merges them into one rope. That heavy combined web is reduced to sliver count by the Drafting Rollers unit, a set of weighted roller pairs that draws and further parallels the fibre, and the Sliver Coiler & Can lays the finished sliver in even coils in a can.

All these motions are timed by the Main Drive through a cam that sequences nip, comb, detach and feed into one repeating cycle, and the Comber Control sets comber speed, noil level and watches sliver count.