Carding, Combing and Spinning

It’s been hard to twist my head around how scoured fibres are transformed into yarn (pun intended). I knew little at the start of this Fibreshed project. Everyone seemed to have slightly different definitions of the same terms, which confused me further. In retrospect, I think each person I met taught me different parts of the process. I couldn’t see the big picture. It’s not until I came to write this post that it started to come together. Please forgive me if I’m wrong on some points and point me in the right direction please!

What’s in a name?

It’s a bit backwards, but I found spinning easier to understand when I sorted out which yarn type was which:

Woollen – this isn’t just fibre from a sheep, but also a style of yarn spinning. Woollen yarns are warm, airy and soft. They often have a fuzzy appearance. While they’re not hard wearing, they’re perfect for scarves, hats, sweaters and felted knits. Their short fibres align in different directions, making air pockets that insulate.

Worsted – a smooth yarn that is hard wearing and drapes well. The tightly twisted fibres of worsted yarns often have a sheen. They’re used for suits, socks and sportswear. Their long fibres all face the same direction, making them very strong.

Wool skeins

Worsted wool skeins in the Tarndwarncoort wool shop

Simple, right? Until you realise that there’s a subset of yarns, known as semi-worsted. This is the yarn that slunk silently in my spinning conversations, waiting for me to discover its meaning! This is yarn that has been prepared with in a woollen style, but spun with a worsted method. It combines qualities of both yarn types. There’s also a semi-woollen which is worsted processed but woollen spun. This seems to be less common.

n.b. when getting this article proof read by actual spinners, I discovered that the definitions of semi-worsted and semi-woollen are different depending on which spinner you ask. I’ve gone with the definition used by a grower and processor in my local Fibreshed.

Alpaca yarn

Semi-worsted yarns from Wool 2 Yarn

Step by step

So now we’ve sorted out where we’re heading, let’s go back to the beginning. After scouring, fibre may be carded, combed and spun. Which of these steps are taken depends on whether you want to felt, knit or weave with the fibre.

Plant fibres like cotton and hemp have a similar but slightly different process to what I outline below. There is equipment to do this with the Melbourne Fibreshed, but I haven’t been able to see these in action yet. I’ll update this post when I know more.

flow diagram of the carding, combing and spinning process

The carding, combing and spinning process

Some processers add water and/or anti-static before starting. The water relaxes the fibre and reduces dust. The anti-static goes a step further to reduce the build up of static during the process, which can break the fibres.

Dehairing – Alpaca, goat mohair and cashmere all have long scratchy fibres mixed in with the softer fibres we prefer to use for clothing. They can be removed by hand, but most people use dehairing machines instead. Unfortunately this ends up as a waste product in the process, because the result is usually mixed with grass seeds. If you can think of a use for it, there’s a lot of fibre processors who’d like to hear your ideas.

The dehairing machine

A dehairing machine: the bin at the front holds the smooth fibre that comes out at the end of the process

Mixing – if the yarn is made from a blend of different fibres, it’s often mixed at this stage. Mills work to ‘recipes’ where fibres are measured by weight, then spread out on top of each other in layers. Chunks of this mix are separated out for processing, helping to keep the ratio mix consistent. With hand processing, staples of fibre are spread out in even layers on a hand or drum carder.

Carding – fibres are often a bit clumped after scouring, so this step opens the fibres up. Carding also removes a little bit of vegetable matter. This is where the process begins to split according to what you’re aiming for. There are woollen carders and worsted carders. The slivers that come off the woollen cards are ready for spinning. Worsted cards begin to align the fibres a little bit before moving on to gilling. 

Carding machines look super cool, with their rotating drums with wires at different lengths. This part of the process seems to be proprietary, so I can’t show you any photos of a carding machine in action. Luckily, hard carders are less shy of paparazzi.

Gilling – carding shakes things up a bit, so the fibre is usually gilled several times. Gilling machines ensure the worsted sliver is a uniform weight throughout. They also further align the fibres.

Gilling machines are the swans of the process – they take the slivers up gracefully. All the work happens where you can’t see it inside the machine, so it looks like magic.

Combing – this is the slowest part. Combing straightens out the fibres, and removes the shortest ones (the waste from this process is fed back into the woollen process, which uses short fibres). After combing, all the fibres are well aligned with each other, and more vegetable matter has been removed. It’s gilled one last time, then passed to felters or spinners as a finished top.

Exiting the combing machine

Fibres exiting the combing machine

Spinning – The woollen sliver or worsted top is condensed into thin roving. This is drawn out and twisted to create a single ply of yarn. To hand spin woollen yarn, the roving is rolled into rolags. It’s then drawn out and spun using a longdraw drafting technique. To hand spin worsted yarn, the roving is drawn out and spun using a short drafting movement. A man’s jumper requires about 1kg of roving. I’ve been told that this would take most hand spinners about 6 days to spin.

A single ply yarn can be used as is, but it is often plyed to increase its strength and stop it twisting in on itself. Spinning creates tension in the fibres, so the yarn is steamed or rested to release that energy.

The state of the industry

The majority of large mills in the Melbourne fibreshed don’t produce local yarn anymore. There are several mini mills that produce semi-worsted yarns for hand knitting and crochet.

Weaving requires a thinner yarn. Waverley Woollen Mills in Launceston produces woven products from carded fleece, spinning fine yarn in the process. The only processors spinning fine yarn in Australia that I know of are Paddock to Ply in Queensland and Certton in Sydney. 

Where does spinning happen in Melbourne?

Cashmere connections, Western district

Fibre Naturally, Dandenong ranges

Velieris, Melbourne

Wool 2 Yarn, Mornington Peninsula

Great Ocean Road Mill, Warnambool

 

Boston Fine Fibres, Queanbeyan

Echo Beach, Mount Barker

Bendigo Woollen Mills, Bendigo

Australian Country Spinners, Wangaratta

Creswick Woollen Mills

First Edition Fibre and Yarns, Euroa

Goldfeilds Mohair Farm, Bookham


Washing and Scouring

At its most basic, scouring is a way of cleaning textile fibres. Wool that’s been shorn from a sheep is known as greasy, or raw wool. Just under 50% of raw wool isn’t actually wool at all: it’s grease, dirt, sweat (suint), burrs and seeds. Many other animal fibres also get washed: alpaca, goat hair and silk all get some level of cleaning. Angora rabbit is apparently an exception. Plant fibres have different processes, although decortated hemp does have a degumming stage.

So many ways to clean fibre!

Raw fibre often contains burrs that can scratch, and may contain disease that can transfer to humans, so it should be treated with caution. Cleaning removes the danger of disease and some burrs. There are many different traditions and ways to wash and scour a fibre. In this context, washing aims to remove large particles and sweat. Scouring uses heat to remove the oils from the fibre. Some people choose not to scour their fibre, because the oils can help the spinning process. Greasy wool is also more water resistant. Wool grease can develop a distinctive smell and gum up modern spinning equipment that is made for clean wool.

Raw huacaya alpaca fleece

Raw huacaya alpaca fleece

Some farmers wash their own fibre, using detergent. Ruth McGregor gives a good description of the process. Their products have what some people believe is a more natural ‘feel’. It’s particularly easy to do this with fibres like alpaca, which don’t have much grease. They do remain rather dusty though! Different sheep breeds have different levels of grease. For example, a Gotland sheep fibre will feel cleaner without scouring than a Merino sheep fibre.

Another way to clean wool fibres is to ferment them. This process uses the oils and sweat already present in the wool to ferment a soap. Zoe had me giggling and in awe over her experiment with this process.

How big business does it

Most commercial fibre you buy is scoured. There are two commercial scouring methods: an aqueous (water) process, and an organic solvent process. Scouring in Australia commonly uses the aqueous process. This process uses large amounts of water, heat and some detergent. The raw fibre gets dropped into 4 – 8 bowls (wash tanks) of hot/warm water and moved around to clean it. After each dunking, excess water is squeezed from the fibre before it drops into the next bowl. Each bowl contains cleaner water than the one that preceded it.

Wool-scouring

The commercial wool scouring process

1 ton of wool will usually contain:

  • 150kg of wool grease
  • 40kg of suint
  • 150kg of dirt (in Australia it averages around 180kg)
  • 20 kg of vegetable matter (although this is likely higher in Australia because we have lots of burrs in our grass)
  • 640kg of wool fibre.

Any grease in the washing water is spun off and sold to be made into lanolin. Solids can be separated from the wash and sent to landfill or composted for agricultural use. The washing water can be recycled up to a point, but scouring plants can still go through up to half a million litres of water a day. Scouring plants in Australia must treat water on their site until it’s safe to add to the sewerage system, or apply to the land. In Melbourne, all the scouring plants are city-based. This means they treat their water on site, then our excellent sewerage system takes over.

Water treatment

Water treatment

After scouring, fibre might be carbonised with sulphuric acid or bleached with hydrogen peroxide. Carbonising removes high levels of vegetable matter and softens the fibre. Bleaching brightens the colour of the wool. Not every plant undertakes these steps; I saw how they are done at Victorian Wool Processors.

acid bath and crushing machine

An acid bath (left), and crushing machine used during the carbonisation process

The final step is to dry the fibre, using drum rollers.

Drying tube

Drying tube

Environmental impact

Scouring has a big environmental impact. It uses large amounts of water (whether it is performed at home or commercially). Depending on the type of wool and equipment used, typically 8-20 litres of effluent liquids are created per 1kg of greasy wool. In some ways a commercial system is preferable, because it can recycle its water several times before disposal.

Waste water is high in potassium and nutrients, particularly nitrogen (although not always in a form accessible to plants). A consideration for Melbourne is that scouring works best with soft water. Our drinking water is soft, but our bore water (which local scouring plants may access as well) is hard. It’s possible to soften water, but those additives pose disposal challenges.

Electricity use is high if heat or extraction processes are applied. There are also many biological and chemical contaminants to deal with. The biological contaminants (like grease and weed seeds) often arrive with fibre from the farm. They need to be dealt with at the scouring disposal stage. The chemical contaminants also arrive direct from the farm (like inorganic fertilisers or biodegradable pesticides), or are added during cleaning (like detergents and bleaches). Sodium sulphate, a byproduct of carbonising, needs proper treatment before application to the land.

Dirt collected for fertiliser

Solid waste collected for fertiliser

The (old) Australian scouring effluent standards say that these contaminants can have a big environmental impact, but this can be mitigated with good management. The Global Organic Textile Standard prohibits use of endocrine disrupters (which can be found in detergents) and phosphates. It restricts bleaches to oxygen bleaches only. There’s a lot more detail in these standards that I can’t comprehend. I’d love to have someone’s more educated view on these documents and what they mean for this process.

What does this mean for consumers?

Washing and scouring fibres is a part of clothing manufacture. Few of our animal fibre clothes will skip this process. While fibres like alpaca and goat don’t need intensive scouring, in Australia they’re often processed like wool so the difference in impact is negligible. Even processing fibre at home will still use a significant amount of water, which needs to be disposed of appropriately.

A proactive approach could be to remember that scouring is a process we shouldn’t approach lightly. Let’s use it when we need something new, but try to reduce how often that happens.

Where does scouring happen in Melbourne?

EP Robinson, Geelong

Velieris, Braybrook, Melbourne

Victoria Wool Processers, Laverton North, Melbourne

edited on 11/1/16 to add details about disease risk in raw wool