Wool

I

Introduction

Wool, common name applied to the soft, curly fibres obtained chiefly from the fleece of domesticated sheep, and used extensively in textile manufacturing. Wool may be differentiated from hair mainly by the nature of the scales that cover the outer surface of each fibre. Wool scales are numerous, minute, and pointed and are attached only at their bases; thus the fibres interlock under pressure (see Felt). The number of scales varies with the fineness and curliness of the fibre. Because of its crimp, or curl, wool has considerable resilience. This quality, together with its high tensile strength and elasticity, gives fine woollen fabrics the ability to retain shape better than cloth made from other natural fibres. Other characteristics of wool, which make it especially desirable for clothing, are its lightness, its ability to absorb moisture, and its insulating properties.

II

Sources of Wool

Wild species of sheep have a short, woolly undercoat covered by long, coarse, straight hair. The hair has entirely disappeared in domestic breeds; selective breeding has improved both the quality and abundance of wool. The quality of the fleece of sheep is also influenced by nutrition, climate, and care. Neglected domesticated sheep have a tendency to produce hair instead of wool.

The fleece of sheep raised for wool is generally shorn once yearly, in the spring or early summer. In regions where the climate is warm throughout the year, shearing may occur twice annually. The fleece is cut close to the skin, usually with mechanical shears, and removed in one piece. The average weight of the fleece shorn from better wool-producing breeds is about 4.5 kg (10 lb). Small amounts of wool come from the skins of lambs slaughtered for meat.

Wool from different parts of the same fleece varies greatly in length of fibre, fineness, and structure. Wool from the shoulders and sides of the sheep is usually superior to that from other parts of the body. Quality varies also with the different breeds of sheep. Pure merino sheep bear the finest wool, and this type has been crossed with hardy sheep producing longer, coarser wool. About 40 per cent of the world's total wool production consists of merino wool, and about 43 per cent is obtained from cross-bred varieties. The remainder is derived mostly from special types of sheep and is employed in the manufacture of blankets, carpets, and tapestries. In addition, a small quantity of fine wool used for clothing is obtained from animals other than sheep. These wool-bearing animals include the camel, the alpaca, the Angora and Kashmir goats, the llama, and the vicuña.

III

Types and Labelling of Wool

The value of wool on the market depends primarily on fineness and length of fibre. Strength, elasticity, amount of crimp, and uniformity are also considered. Two different systems are followed in wool processing, the woollen system and the worsted system. In the woollen system, the fibres are carded and then spun. In the worsted system, the fibres proceed to a combing process, which separates the long from the short fibres. The long fibres are then formed into smooth compact strands ready for spinning into yarn. Worsteds are not napped but are finished with a smooth surface. Uniform lengths of relatively fine fibres are very important in the worsted system, because short fibres are difficult to spin. In the woollen system, on the other hand, fibres of mixed lengths may be used. Fine wools are classified according to the length of fibre. Longer fibres used in the manufacture of worsteds are called combing wool; shorter fibres employed for yarns used in soft, woven fabrics are known as carding wool.

Wool is marketed worldwide by the International Wool Secretariat (IWS), which is based in Ilkley, North Yorkshire. The “Woolmark” instituted by the IWS indicates that garments bearing this sign are made of pure new wool. Pure new wool is wool that has not previously been used in manufacture. Reprocessed wool refers to fibre reclaimed from woven scraps and clips accumulated from the cutting table, from samples, and from mill ends. These remnants, never previously used, are reconverted into a fibrous state and then reprocessed into the manufactured product. Reused wool is wool fibre recovered from products used by consumers, respun, and rewoven. This category is less important now than formerly, because of competition from synthetic fibres.

IV

Wool Production

Australia is the world's largest producer of raw wool, growing about 29 per cent of the total world supply. Other leading producers are the former Soviet republics, New Zealand, China, Argentina, South Africa, and Uruguay. Yorkshire and Scotland, where yarn, cloth, and woollen garments are produced, are the British centres of the wool industry. Wool is produced both from sheep in these areas, and in many other parts of Britain. It was once a major source of revenue in the Cotswolds and in Wales. The wool industry as a whole has, however, suffered from competition from synthetic fibres.