From wool to yarn

Fineness is measured in micrometres, thousandths of a millimetre; in everyday speech they are usually called microns. A merino fibre is three to four times thinner than a human hair. Fine wool is densely crimped, with up to ten waves per centimetre of staple, and it is the crimp that makes yarn lofty and springy.

The Russian standard GOST 30702 divides wool into homogeneous, made of one type of fibre, and heterogeneous, where fine down grows alongside coarser intermediate fibres and hair. Homogeneous wool can be merino, crossbred, tsigai or crossbreed. By fineness, wool is graded into Bradford quality numbers: the higher the number, the finer the fibre.

Coarse-wool breeds are often shorn twice, in spring and autumn, so the standard distinguishes spring and autumn wool. The fleece is thrown onto a table and the soiled edges are skirted straight away: leg wool and locks with burrs and dung. Belly wool comes off first during shearing and is packed separately.

The most valuable wool grows on the shoulders and sides: long, even in fineness and clean. Towards the britch the fibre becomes coarser, and on the back it is often weathered by sun, dust and rain.

One fleece yields several sorts: shoulders in one place, sides in another, britch and locks into the lower grades. A mesh table lets sand and fine dirt fall through before scouring.

The sorted wool is made up into even lots. The more uniform a lot is in fineness and length, the more gently it can be scoured and carded, and the more consistent the tops will be.

In the first bowls the liquor is heated to 60–65 °C: enough to melt the wool grease without harming the fibre. The wool is not stirred by a propeller but gently moved along by harrows. Between bowls, squeeze rollers press out the dirty liquor.

The last bowls are for rinsing. The clean wool is dried with hot air and pressed into bales. Wool grease is recovered from the spent liquor and refined into lanolin for cosmetics and pharmaceuticals.

The lots are opened and sprayed with a lubricant emulsion. It reduces friction and static, so fewer fibres break during carding.

The wool is then laid down in the blending bin in thin horizontal layers and taken off vertically, through all the layers at once. That way every handful of fibre carries every lot of the blend in the same proportion.

Every cylinder and roller is covered in card clothing: thousands of fine steel teeth. The main cylinder, the swift, turns fast; the workers turn dozens of times slower. In a gap of less than a millimetre they compete for every tuft and split it; the strippers return the fibre to the swift to be worked again.

A tuft holds about ten thousand fibres. If each worker splits it in half, it takes 13 to 14 such splits to reach single fibres. That is why several worker pairs sit around the swift, and a card may have several swifts in a row.

The fancy, with long flexible pins, lifts the fibres to the surface of the clothing; the doffer collects them, and the doffer comb strips the web off it. A trumpet gathers the web into a sliver, and the coiler lays it in rings into a can.

The worsted system is the longest: gilling, combing, roving. It needs long fine wool and gives a smooth, strong, fine yarn. This is our road, and the one we follow from here.

The woollen system is the shortest: the web is split straight into slubbings and spun. The yarn is bulky, soft and hairy. The semi-worsted system skips combing but passes the sliver through gill boxes several times; it needs wool of 100–120 mm staple.

The pins are set in fallers that travel along with the sliver, while the front rollers pull it faster than the back rollers feed it. That speed difference, the draft, makes the sliver thinner, and the pins keep the fibres from bunching.

Several slivers are fed in at once and combined into one. This doubling averages out the weight: thin and thick places in different slivers cancel each other out.

The feed gill pushes the fringe forward a few millimetres. The nippers grip it, and the circular comb with dozens of rows of pins combs the free end. Then the nippers open, the top comb drops, and the detaching rollers draw the fibres off, pulling their tails through the pins of the top comb.

Each new tuft is laid overlapping the previous one, and the tufts join up into a continuous sliver. A brush cleans the noil out of the circular comb: short fibres, neps and vegetable matter. Noil is valuable too; it goes into woollen yarns and felt.

The result is a top: a continuous rope of long parallel fibres, wound into a ball or bump. A top has about 25,000 fibres in its cross-section; a fine yarn spun from it will have only about fifty.

In doubling we combine up to six lots of tops into one sliver: to even out a large delivery, to blend wools of different origin, or to make a melange from dyed tops.

In the French worsted system, roving is not twisted but rubbed: after the drafting zone it passes between two aprons that move back and forth across the strand. They roll the fibres into a round strand held together by fibre cohesion rather than twist.

The finished roving is wound onto spools. On the spinning frame, every spool becomes one yarn.

A double-apron drafting system thins the roving to the required count. The spindle turns at thousands of revolutions a minute and drags the traveller, a tiny clip, around the ring. Each turn of the traveller puts one turn of twist into the yarn, and the yarn balloons as it flies.

The ring rail moves slowly up and down, so the yarn builds an even cop. Hundreds of spindles run on one frame at the same time.

Twist direction is marked with letters: in Z twist the fibres run like the middle stroke of the letter Z, in S twist like the letter S. Singles are usually spun with Z twist, and plied together with S twist.

Yarn thickness is given as the metric count Nm: how many metres of yarn weigh one gram. The higher the count, the finer the yarn: a gram of Nm 10 is 10 metres long, a gram of Nm 48 is 48 metres. 2/32 means two Nm 32 yarns twisted together: the plied yarn is twice as thick as a single and weighs the same as Nm 16. Russian GOST standards give thickness in tex, grams per kilometre: Nm 32 is about 31 tex.

The count is chosen for the product. Hand-knitting yarn is thick, usually 100–400 metres per 100 grams, or roughly Nm 1–4. Knitting machines and weaving use fine counts such as 2/28–2/48. Twist is counted in turns per metre: the finer the yarn, the more turns it needs to hold together. High twist makes yarn strong and smooth; low twist makes it soft and lofty.

The yarn is steamed in an autoclave, which sets the twist so the yarn no longer snarls. Wool can be dyed at any stage: as loose fibre, as top, in hanks or on packages.

Machine-knitting yarn is rewound onto cones and waxed: a thin layer of paraffin reduces friction on the needles. Hand-knitting yarn is wound into hanks and balls of 50–100 grams.

Pekhorsky Textile spins our tops into yarn under the Pekhorka and Troitsk Yarn brands. Merino wool remains the heart of their wide range.