Natural white yarn
Made of non-dyed, natural white, spinning material. Piece-dyed after weaving or knitting. The source material for so-called piece-dyed items.
Also made from natural white spinning material; these are dyed as yarn or in a strand or on the dyeing cheese.
Top- or Flock-Dyed Yarns
The fibre material is already dyed as top or flock loose fibre material then blended and spun. They include Vigoureux yarn, which is first printed as top and then spun.
In order to produce fancy yarn irregularities, like moiré or slubs, are created in spinning or on special fancy twisters by varying yarn components and feed speeds of the individual threads. Examples are bouclé, loops or knot yarns.
The worsted spinning process is the most elaborate of the processes included here. It requires a relatively fine material, which must be done precisely in order to obtain a particularly smooth, round yarn that is very finely spun. For this purpose: the finer the desired yarn count, the finer the fibre material used needs to be.
The processing is similar to that of woolen yarn. In the combing, the fibre material is separated into single fibres on the worsted carding machine and at the same time the largest impurities like bur, pieces of straw or wood are removed. The fibres are also already oriented lengthwise and combined into a sliver. This is combed out on the combing machine, i.e. short fibre material as well as other impurities of plant origin are removed and the fibres are parallelised.
In the spinning preparation different tops are combined into a spinning batch. Different slivers pass through a drawing unit together, in which optimal blending of the fibres takes place. According to the desired yarn count, this process is repeated several times until the rove is finished. On the ring spinning frame, this is turned into worsted thread.
A distinction is made primarily between worsted and woollen yarn. This merely indicates the spinning technology and not - as is often wrongly assumed - the quality.
Other than that, there are several variations of the two principal techniques.
Woollen yarn is mainly made up of shorter to medium-length fibres and a very small percentage of longer fibres; spinning medium, is sometimes added.
The pre-treatment for spinning is carried out by:
Opening and loosening the fibre material
Blending the different material components
Adding auxiliary agents (fibre lubricant like spinning oil, and so on) to improve the workability in the mechanical processes (carding and spinning).
The opened, blended and lubricated fibre material is now fed into the carding machine (a roller system equipped with wire hooks) and broken up into single fibres. This way the fibres are parallelised lengthwise. A coherent fleece is taken from the last roller and separated into strips of approx. 1 cm by condenser tapes.
After the subsequent rubbing, these strips are slightly rounded and result in the so-called rove.
This semi-finished product is now twisted and simultaneously drawn on the ring spinning frame or self-actor mule. The extent of twisting determines the yarn count depending on the number of rotations of the spindle and its rotation direction, the yarn twist and the direction of twist. The winding up of the finished yarn on a cardboard or plastic sleeve sitting on the spindle happens simultaneously.
The typical woollen yarn thread is thick and voluminous. Depending on the fibre components, it is possible to obtain either a particularly soft or rustic yarn. Examples are the soft lambswool yarn and the rustic Shetland or Tweed yarn.
Twisting and Plying
Twisting means rotating the thread around itself. Plying means twisting together two or more twisted or untwisted threads. Plying increases the strength of yarns and improves their regularity.
The following applies for the denomination of the twist direction for yarns and twines: The twist direction of yarns is described with z and s, that of the twines with z and s, i.e. parallel to the diagonal line of each letter in each case.
In twine numbering, the Nm of the single threads is indicated first followed by the number of threads. A worsted ply yarn 64/2 is therefore a twine made from two threads of Nm 64. The final count is Nm 32. A 48/2/3, therefore a triple-plied yarn made from an Nm 48/2 twine; resulting in a final twine count Nm 8.
Twines that require two or more production steps are called compound ply.