【正文】 ，平均直徑約70微米。The width of wool also varies considerably. Fine fibers such as Merino have an average width of about 15 to 17 microns。Wool fibers vary in length from to about 38 cm. Most authorities have determined that fine cools are usually from to cm。皮質(zhì)大概占了纖維團(tuán)的90%。外面那層，稱為角質(zhì)層，由鱗片形成。細(xì)羊毛沒(méi)有粗羊毛那樣清晰突出的鱗片，但他們可以在高倍鏡下辨識(shí)出來(lái)。棉紗線用作電動(dòng)機(jī)和工作服的加強(qiáng)帶。棉的機(jī)織物可以充分拉開(kāi)，它具有良好的透氣性以供舒適。For recreational use, cotton has traditionally been used for tenting and camping gear, boat sails, tennis shoes and sportswear. Cotton is particularly wellsuited for tent. A tent fabric must be able to breath, so that the occupants are not smothered in their own carbon dioxide. Furthermore, exchange of air with the outside atmosphere reduces the humidity within the tent and keeps it from being stuffy. Fabrics woven from cotton can be open enough to provide good air permeability for fort. Tents should also shed water, when wet by rain, cotton yarns swell, reducing the interstices between the yarns and resisting the penetration of water. Today, however, heavy canvas gear is being supplanted by lightweight nylon in tenting ，棉織物一向應(yīng)用于帳篷和野營(yíng)裝備、船帆、運(yùn)動(dòng)鞋和運(yùn)動(dòng)服。In home furnishings, cotton serves in durable, generalservice fabrics. Although they may lack the formal appearance of materials made from other fibers, cotton goods provide a fortable, homey environment. Cotton fabrics have been the mainstay of bed linens and towels for decades, because they are fortable, durable, and moistureabsorbent. Polyester/cotton blends provide the modern consumer with noiron sheets and pillowcases that retain a crisp, fresh ，棉產(chǎn)品擔(dān)當(dāng)了實(shí)用而全方位服務(wù)的織物。在衣物方面，棉帶來(lái)了舒適、在光下快干、色彩持久、容易打理的服飾。此外，所吸收的水作為一種內(nèi)部潤(rùn)滑劑，賦予纖維較高水平的靈活性。通常這種大量的外來(lái)物質(zhì)的吸收會(huì)導(dǎo)致內(nèi)部應(yīng)力較高，導(dǎo)致纖維弱化。棉花自然掛干或烘干機(jī)烘干會(huì)長(zhǎng)時(shí)間保持其白度。最突出的是棉一旦放在持續(xù)潮濕的環(huán)境下會(huì)發(fā)霉。正是氫鍵的斷裂與重鍵使得織物保持褶皺，所以棉織物需要熨燙。也許棉產(chǎn)品主要的缺點(diǎn)就是其會(huì)起皺以及難以抗皺。因此，這對(duì)維持體溫有幫助。因?yàn)槔w維素的羥基基團(tuán)，使得棉花對(duì)水有很強(qiáng)的吸引力。當(dāng)水進(jìn)入纖維棉，棉開(kāi)始膨脹，其截面變得更圓。Unfortunately, the hydrophilic nature of cotton makes it susceptible to waterborne stains. Watersoluble colorants such as those in coffee or grape juice will penetrate the fiber along with the water。棉纖維的剛性使得紗線抗皺性能降低。Cotton is a moderately strong fiber with good abrasion resistance and good dimensional stability. It is resistant to the acids, alkalies, and organic solvents normally available to consumers. But since it is a natural material, it is subject to attack by insects, molds and fungus. Most prominent is the tendency for cotton to mildew if allowed to remain ，強(qiáng)度適中的纖維。Cotton resists sunlight and heat well, although direct exposure to constant strong sunlight will cause yellowing and eventual degradation of the fiber. Yellowing may also occur when cotton goods are dried in gas dryers. The color change is the result of a chemical reaction between cellulose and oxygen or nitrogen oxides in the hot air in the dryer. Cottons will retain their whiteness longer when linedried or dried in the electric ，耐熱，盡管直接暴曬在持續(xù)的強(qiáng)光下會(huì)引起發(fā)黃，并最終引起纖維的降解。Of major interest is the fact that cotton yarn is stronger when wet than when dry. This property is a consequence of the macroand microstructural features of the fiber. As water is absorbed, the fiber swells and its cross section bees more rounded. Usually the absorption of such a large amount of foreign material would cause a high degree of internal stress and lead to weakening of the fiber. In cotton, however, the absorption of water causes a decrease in the internal stresses. Thus, with less internal stresses to overe, the swollen fiber bees stronger. At the same time, the swollen fibers within the yarns press upon each other more strongly. The internal friction strengthens the yarns. In addition, the absorbed water acts as an internal lubricant which imparts a higher level of flexibility to the fibers. This accounts for the fact that cotton garments are more easily ironed when damp. Cotton fabrics are susceptible to shrinkage upon ，棉紗線在潮濕環(huán)境下比在干燥環(huán)境下強(qiáng)度更大。然而，棉纖維吸水導(dǎo)致內(nèi)部應(yīng)力減少。這解釋了棉衣物潮濕時(shí)更容易熨燙，棉織物洗水時(shí)易收縮。它主要的缺點(diǎn)是棉紗線會(huì)縮水和棉布會(huì)起皺。雖然他們可能沒(méi)有其他纖維材質(zhì)的美觀，但棉織品（為我們）提供了一個(gè)舒適，溫馨的環(huán)境。棉織物特別適合制作帳篷。帳篷應(yīng)該能使水分流走，當(dāng)被雨水打濕，棉紗膨脹，減少紗線之間的間隙，提高防水性。Lesson Five Structure and Properties of WoolUnder the microscopic observation, the length of the wool fiber shows a scale structure. The size of the scale varies from very small to paratively broad and large. As many as 700 scales are found in 1 cm of fine wool, whereas coarse wool may have as few as 275 per cm. Fine wool does not have as clear and distinct scales as coarse wool, but they can be identified under high ，羊毛纖維的長(zhǎng)度顯示出鱗片結(jié)構(gòu)。A cross section of wool shows three distinct parts to the fiber. The outer layer, called cuticle, is posed of the scales. These scales are somewhat horny and irregular in shape, and they overlap, with the top pointing towards the tip of the fiber。這些鱗片形狀有點(diǎn)棱角，并不規(guī)則又互相重疊，由毛根指向毛尖；它們類似魚(yú)鱗。在纖維的中心是中腔。 medium wool from to cm。 whereas medium wool averages 24 to 34 microns and coarse wool about 40 microns. Some wool fibers are exceptionally stiff and coarse。The wool fiber cross section may be nearly circular, but most wool fibers tend to be slightly elliptical or oval in shape. Wool fibers have a natural crimp, a builtin waviness. The crimp increases the elasticity and elongation properties of the fiber and also aids in yarn manufacturing. It is threedimensional in character。它呈三維結(jié)構(gòu)的；換句話說(shuō)，它不僅圍著纖維軸上下纏繞而且左右纏繞。The color of the natural wool fiber depends on the breed of sheep. Most wool, after scouring, is a yellowishwhite or ivory color. Some fibers may be gray, black, tan or 。 when wet, it drops to to g/d. Compared with many other fibers, wool is weak, and this weakness restricts the kinds of yarns and fabric constructions that can be used satisfactorily. However, if yarns and fabrics of optimum weight and type are produced, the enduse product will give mendable wear and retain shape and appearance. Fiber properties such as resiliency, elongation, and elastic recovery pensate for the low strength.；濕潤(rùn)時(shí)。Wool has excellent elasticity and extensibility. At standard