Wool processing

Spinning

Rovings, slubbing or slivers are spun and twisted into a continuous unbroken thread to make the final wool yarn.

Drafting

Drafting reduces the thickness of slivers and extends their length. This is done between two pairs of rollers; the feeder pair turn relatively slowly, while the drawing or delivery pair revolve much faster. The difference in the revolving speed can be as high as a ratio of 1:200 (for high-draft, worsted spinning systems) or less that 1:1.5 for typical woollen spinning systems.

Spinning

Twisting the fibres increases the strength of the strand of yarn. In commercial spinning plants the roving, slubbing or sliver is fed from large spools through rollers, drawing the yarn out to its final diameter, and wound onto revolving bobbins to give it a final twist. For additional strength or different effects, two, three or more strands of wool can be twisted together forming ply yarn. Other effects can be created by twisting different colours and textures together.

In commercial spinning, worsted yarns normally need to be around 40 fibres thick, while woollen yarns need to be 130 thick for the yarn to hold together and not break during spinning. Combing and gilling has made the fibres more parallel, so they have more contact points and hold together better.

If the fibres in the slubbings or sliver are short, they either need more twist or more fibres to hold the yarn together. This is normally the case with woollen yarns. Longer fibres don’t need to be twisted as much, or there can be fewer of them in cross section in the yarn. This is typical in worsted yarns.

Now the wool yarn is ready to be made into to a wide variety wool products, from either felted, woven or knitted fabrics, or by weaving and tufting carpets and rugs. However, it may still need to be dyed.