Today I accompanied a group of students on a visit to Diamond Fibres in Horam, Sussex. The company processes wool for worsted spinning, rather than woollen spinning, so concentrates more on longer staple fleece.
Starting in the sorting shed, we were shown round by Roger, the owner, and given a really thorough introduction to the processes involved in changing raw fleece into yarn.
There was a Wensleydale fleece on the picker, which Roger explained had already been washed once at 60 degrees to remove the first lot of dirt and oil and then dried. After picking, which would open up the compressed curls that the first wash had not reached, it would be re-washed and dried before further processing. He reckoned that it may in fact require a third pick and wash.
The students were looking tired just at the thought of this!
Following picking, the next process is carding the fibres to start aligning them in parallel into a continuous ”sliver’ of fibre. Unlike my meek little hand carder, they have a carding machine with 16 drums of metal, not wire, teeth. At this stage, any short fibres will still be in the sliver, it isn’t until combing that these will be removed.
The sliver begins to look more like something that is spinnable, but there are still thin and thick sections along its length. To eliminate these and even out the sliver it goes through ‘gilling’. Diamond have two of these machines. The first one has wider spaced teeth, and is used at this point, whilst the second is much finer and bulks up and evens out the sliver later on after combing.
When the sliver goes into the gilling machine, two are fed in at once, producing one thicker sliver of uniform thickness.
The fibre will in all likelihood go through a second gilling, during which the output sliver gradually bulks up, according to the machine settings, to achieve the required grams per metre.
If the requirement is for carded roving for hand spinning, this will be the last process. It may even be stopped earlier on, depending on what condition fibre is required.
If however, the desired outcome is combed sliver, then it has to go through the combing machine. This takes up to sixteen slivers side-by-side through the combs, crimping the final sliver to compress the fibres together and prevent breakage. It looks like doll’s hair emerging from the machine. Any remaining short fibres, nepps, noils or debris fall out into a waste bin beneath the combs.
This combed sliver has become slightly uneven during the combing process, and this is when it goes through the finer gilling machine to produce a consolidated, even sliver ready to have a small amount of twist introduced, (about four turns per inch) to make a softly twisted roving.
This roving is then drafted out into a thinner roving, and finally drafted and spun into singles weighing approximately 0.2g per metre. Amount of twist can be controlled to produce softer or firmer yarns at both singles and plying stages.
The singles can be plied into 2, 3, 4 etc ply yarns according to need. 2 ply tends to be flat, 3 ply rounded, and 4 ply has a square profile. To make a cable yarn, 2 x 2ply can be twisted together.
2ply yarn made from two of the 0.2g/metre singles would weigh approximately 0.4g per metre. This would yield something like 250 metres per 100g, which is within the DK category of yarn, and will be between 12-14 WPI.
Of course, as Roger pointed out, natural fibres do not conform as precisely as synthetics do, so there are highly likely to be variations in weight to length of a hank of yarn depending on humidity and other physical conditions when it is weighed. Oh the joy of natural fibres, thats why we love them!
I think the students now really appreciate how much work goes into making the yarns they pick off the yarn-store shelf. One even went so far as to say that they would never again complain about yarn being so expensive!