Warp and Weft
Prior to weaving, the warp yarns are prepared and assembled in a parallel manner. This preparation stage is known as warping, and is carried out on a machine known as a warping machine. Because lot sizes for wool, in comparison to some other fibres, tend to be relatively small, the method of sectional warping is the most commonly used.
Firstly the warp yarns are fed from a creel, and wrapped in small sections around a rotating taped drum, and then from the drum they are unwound and transferred to a beam, which fits directly onto the loom.
Most warps yarns are two-fold (2xply), because of greater strength and resistance to abrasion. Weft yarns are either singles (1xply) or two fold, depending on the required aesthetics and performance of the woven fabric to be produced.
During weaving there are three primary motions, these include:
- shedding: where some of the warp yarns are lifted up to form a tunnel, where the weft yarn will be inserted
- picking: insertion of the weft yarn
- beating up: beating the weft yarn, so it lies adjacent to the previous weft yarn.
In addition to these there is a let-off and take-up action which moves the fabric through the loom in a controlled way.
Different types of looms can be used to produce woven fabrics made from wool, with the exception of water jets (wool absorbs too much moisture).
Today, Rapier weaving looms are the most commonly used, because they are much quieter than projectile types (shuttle looms).