Mostly woollen fabrics are dyed by using Winch Dyeing machine. The dyeing machine derives its name "Winch" as the fabric rope gets circulated in the machine by way of a mechanical action of a horizontal rotor or reel, called as a winch or sometimes wince. The cross-section of the winch rotor may be circular or elliptical.
As shown in the diagram below, the winch dyeing machine has a front compartment, a perforated partition separates it from the main dyeing chamber. It is this front compartment where dyestuff and dyeing auxiliary additions are made. Gradually they move to main dyeing vessel from there. The process works like this first a series of fabric ropes are immersed in the dye bath. This fabric ropes must be of equal lengths. A part of each rope is then taken over two reels or over the winch itself. In the subsequent course of dyeing operation a rope of fabric is circulated through the dye bath and the winch. The dyestuff and auxiliaries are dosed manually or automatically according to the recipe method.