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Wool/Yarn Types
Wool comes in varying thickness, depending on the kind of sheep that produced the wool and the part of the body on which the fibres grew. Fibres from the sides and flanks are typically longer and coarser than those from the belly, which are usually soft and fine. A fine fibre may be only an inch or two long and less than a thousandth of an inch thick. Coarser fibres may be three times as thick and from several inches to a foot or more long. The finest wools are used for woollen underwear. However, it does not wear as well as coarser fibres. Tough wool is used to make durable carpeting. Intermediate wool fibres are best for making durable, long-lasting knit winter hats and sweaters.
Wool from the sheep is covered with a waxy grease that is made into lanolin. Face creams are made from lanolin, which has been washed from raw wool and purified. Lanolin is also useful in making lubricants, soaps, polishes, inks and ointments. Raw wool is washed with soap to remove the lanolin and dirt. The remaining cleaned wool can weigh as little as 30% of the original raw wool, though 50-60% is typical.
If the final fabrics will differ in colour from the original wool, then dyeing is required. Dyeing can be delayed until the final garment is created, if a single colour is used. However, to create the colourful wool hats and wool sweater-jackets we sell, then dyeing is needed either just before or just after spinning.
Wool can be readily coloured by soaking it in hot water in which dye has been dissolved. To keep the colour from fading after exposure to sun, the dye must be made “fast” or permanent. The fastest colours are produced with dyes that penetrate the inner structure of the fibre material.
Colouring is usually done by soaking the wool in large vats filled with hot solutions of dye. Great kettles with lids that can be clamped shut are used, so that steam pressure can be built up inside the kettle in order to force the dye deep into the wool fibres.
The old-fashioned method of spinning yarn on a hand-held spindle was very slow. It took weeks to make enough yarn for one coat or dress. Then, about five hundred years ago, the machine called a spinning wheel became common. It was made of wood and had a spindle which was turned rapidly by a string belt driven from a large wheel, rotated by hand or with a pedal. Loose strands of fibre ready to be spun were held on a forked stick called a distaff, and were fed onto the spindle by the spinner. The spindle both twisted the fibres into yarn and wound the yarn onto a spool, or bobbin. Today spinning is done mechanically using high-speed machinery.
When wool fibres are matted together, their scales become more and more entangled. This entanglement makes possible a process called felting. After the wool fibres have been softened by moisture, acids, and heat, they can be rubbed and pressed together to make felt cloth, a strong, smooth, bulky material that contains no spun and woven threads.
Felt cloth can be made in any thickness or size. Heavy felt is used to make thick pads for use under rugs and carpets and for cushioning machinery. Finer felt is used in making felt hats and as cloth for making skirts or jackets.
According to one story, felt was discovered accidentally by Arabs who stuffed wool under their horses’ saddles when these rubbed sore places on the animals’ bodies. Softened by hot and acid sweat, the wool gradually packed into lumpy sheets of felt. Another story says that felt was invented by a shepherd boy who stuffed wool into his shoes to protect his sore feet.
The natural qualities of wool fibres make for the soft fluffiness of woollen cloth, its toughness and resistance to tearing, and its ability to wear well and to hold dyed colours. The fineness and elasticity of the fibres, their natural curl and crinkle, and the scales they carry, all lend a share to these good qualities.
When moistened and heated, wool fibres become slightly plastic, so that they can be straightened or bent. Because of this characteristic, a wool suit can be smoothed and brought back to its original shape when it is pressed with a hot steam iron. The fibres are softened by the heat and moisture and are moved into the desired position, where they harden as they cool.
Cloth made from wool does not unravel at its cut edges as readily as that made from other fibres, for the scales on the wool fibres hold them together. Again, woollen cloth stays cleaner than other kinds of cloth because the scaly fibres help keep dirt from passing into it.
Perhaps most important of all is the way woollen clothes keep their wearer dry. Drops of water are more likely to run off a woollen surface than to soak in as they do on the thirsty fibres of cotton. Even after the natural grease has been washed from wool fibres, they have a waxy outer coating that keeps water from penetrating them readily. In addition, the inside of the fibre is made of a material that can soak up large amounts of water.
If a person’s feet get wet when he is wearing heavy woollen socks, they may stay fairly warm because wool can soak up quite a bit of moisture without becoming a good conductor or heat, and also because some heat is given out by the wool fibre itself when it accumulates water.
Although most summer clothing is made of cotton, linen, or synthetic fibres, strangely the same wool that keeps us warm is also good to keep us cool. When our bodies get hot we perspire – water comes out of the sweat glands in our skin and evaporates in the air. This cools us. Under a very hot sun, we need to wear clothes that will keep the sun’s rays from shining directly on our skin and at the same time will not interfere with the evaporation of water from it. Woollen cloth not only has holes between its woven yarns, but between the fibres in the yarn. It also absorbs much moisture. Surprisingly, the Arabs and other peoples who live in the Sahara and Arabian deserts wear a garment called a galabeah, which keeps them cool in the daytime and warm at night. The galabeah is a loose gown often made of wool, which looks something like a long nightshirt and coves the wearer from his shoulders to his ankles. As the Arab walks, his gown swishes and pumps dry air up and down his legs. This air absorbs the perspiration evaporation from his body and carries the vapour away through the tiny holes in the woollen cloth.
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