Carding is the processing of brushing raw or washed fibers to prepare them as textiles. A large variety of fibers can be carded, anything from dog hair, to llama, to soy fiber (a fiber made from soy beans), to polyester. Cotton and wool are probably the most common fibers to be carded. Not all fibers are carded; Flax and bast, for example, is retted then threshed.
Carding is used to take unordered fibers and prepare them for spinning by either the worsted or woollen process or to produce webs of fibre to go into nonwoven products depending on the mechanism at the output from the card. It can also be used to create blends of different fibers or different colors. The process of carding mixes up the different fibers, thus creating a homogeneous mix of the various types of fibers, at the same time as it orders them and gets rid of the tangles. Machine cards for carding wool also have rollers and systems designed to remove some vegetable contaminants from the wool.
The two main ways to card fibers are by hand and by machine.
Hand carders look similar to dog brushes. They are used two at a time to brush the wool between them until all the fibers in a bunch align in the same direction more or less. Carding is an activity normally done sitting down outside or over a drop cloth, depending on the wool's cleanliness. If the wool contains a lot of vegetable matter, that will fall out during the carding process, which is the reason for a drop cloth. If the carding is being done to mix two pre-carded fibers, a drop cloth is not generally used.
To card, the person carding holds a carder in each hand. The carder in their non-dominant hand (left for most people) is rested on their leg. They place a small amount of fiber on this card and pull the other carder through, while taking care to catch some of the fibers. By catching some fibers on the moving card, the fibers are separated, which allows vegetable matter to fall out, and they are aligned. Catching too many fibers makes it hard to pull the carders apart. This process, repeated many times, transfers small amounts of the wool to the other carder. Once all the wool has been transferred, the person carding repeats this process until all the fibers are aligned and the fiber is satisfactorily clean of debris. They then roll up their carded wool into a neat rolag.
Hand carders come in a wide variety of sizes, from ones two by two inches to ones four by eight inches. The small ones are called flick carders, and are used just to flick the ends of a lock of hair, or to tease out some strands for spinning off of. The density of the teeth, and the shape of the carders also varies. For finely carded rolags, one uses carders with more teeth. The type of fiber, its length, weight and characteristics, can also determine how many teeth are wanted per inch on the carders. Hand carders can be either flat backed or curved, which is a matter of personal preference.
The carders used currently in woolen mills differ very little from machines used twenty to fifty years ago, and in some cases the machines are from that era. For wool, and wool-like fibers (such as llama, alpaca, goat, etc.), fibers are fed onto a series of rollers. Depending on the size of the carder, the number of rollers differs. The ones that fit on the kitchen table typically have two drums, or rollers. One is small, and used to catch the fibers and feed them in. The other drum takes the fibers from the first drum, and, in the process of transferring them from one drum to another, the fibers are straightened out and told to be orderly. The picture above is a small drum carder.
A carder that takes up a full room works very similarly, the main difference being that the fiber goes through many more drums, which normally get finer as the fiber progresses.
When the fiber comes off the drum, it is in the form of a bat, or a flat, orderly mass of fibers. If a small drum carder is being used, the bat is the length of the circumference of the big drum, and is often the finished product. A big drum carder though, will then take that bat and turn it into roving, by stretching it thinner and thinner, until it is the desired thickness (often rovings are the thickness of a wrist). (A rolag differs from a roving ( or ) because it is not a continuous strand, and because the fibers end up going across instead of along the strand.) Cotton fibers are fed into the machine, picked up and brushed onto flats when carded.
Some hand-spinners have a small drum carder at home especially for the purpose of mixing together the different colored fiber that they buy already carded.
In 1748 Lewis Paul of Birmingham, England invented the hand driven carding machine. A coat of wire slips were placed around a card which was then wrapped around a cylinder. Daniel Bourn obtained a similar patent in the same year, and probably used it in his spinning mill at Leominster, but this burnt down in 1754. The invention was later developed and improved by Richard Arkwright and Samuel Crompton. Arkwright's second patent (of 1775) for his carding machine was subsequently declared invalid, because it lacked originality.
From the 1780s, the carding machines were set up in mills in the north of England and mid Wales. The first in Wales was in a factory at Dolobran near Meifod in 1789. These carding mills produced yarn particularly for the Welsh flannel industry.
By 1838, the Spen Valley, centred around Cleckheaton had at least 11 carding factories and by 1893 it was generally accepted as the carding capital of the world. Even now, Cleckheaton's carding legacy lives on through companies such as Garnett Control, Bridon Wire, Cold Drawn Products and ECC.
Carding of wool can either be done "in the grease" or not, depending on the type of machine and on the spinner's preference. "In the grease" means that the lanolin that naturally comes with the wool has not been washed out, leaving the wool with a slightly greasy feel. The large drum carders do not tend to get along well with lanolin, so most commercial worsted and woollen mills wash the wool before carding. Handcarders (and small drum carders too, though the directions may not recommend it) can be used to card lanolin rich wool. A major benefit of working with the lanolin still in the wool is that it leaves you with soft hands.