Lesson Five第五课Structure and Properties of Wool羊毛纤维的结构和性能Under the microscopic observation, the length of the wool fiber shows a scale structure. The size of the scale varies from very small to comparatively 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 magnification.显微观察下，羊毛纤维的长度显示了一个规模结构。
规模的大小从比较广阔的和大的很小变化。
多达700的尺度是羊毛的1厘米，而粗毛可能为每厘米275少。
细羊毛没有粗羊毛为清晰明确的尺度，但他们可以在高放大倍数的确定。
A cross section of wool shows three distinct parts to the fiber. The outer layer, called cuticle, is composed 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; they are similar to fish scales. The major portion of the fiber is the cortex (composed of cortical cells ; this extends toward the center from the cuticle layer. Cortical cells are long and spindle-shaped and provide fiber strength and elasticity. The cortex accounts for approximately 90 percent of the fiber mass. In the center of the fiber is the medulla. The size of the medulla varies and in fine fibers may be invisible. This is the area through which food reached the fiber during growth, and it contains pigment that gives color to fibers.羊毛的横截面显示三个不同部分的纤维。
外层，称为角质层，由刻度。
这些鳞片形状有点角质和不规则的，和他们的重叠，与顶端指向尖端的纤维；他们是类似鱼鳞。
纤维的主要部分是皮质（由皮层细胞）；这延伸向角质层的中心。
皮质细胞长梭形和提供纤维的强度和弹性。
约百分之90的纤维质皮层帐户。
在光纤的中心是髓质。
延髓的尺寸变化和细纤维可能是看不见的。
这是通过食品达到纤维在生长过程中的区域，它包含颜料，使色纤维。
Wool fibers vary in length from 3.8 to about 38 cm. Most authorities have determined that fine wools are usually from 3.8 to 12.7 cm; medium wool from 6.4 to 15.2 cm; and long (coarse wools from 12.7 to 38 cm.羊毛纤维长度在3.8到38厘米不等。
大多数当局已经确定，细羊毛通常从3.8到12.7厘米；中毛从6.4到15.2厘米；长（粗）从12.7到38厘米的羊毛。
The width of wool also varies considerably. Fine fibers such as Merino have an average width of about 15 to 17 microns; whereas medium wool averages 24 to 34 microns and coarse wool about 40 microns. Some wool fibers are exceptionally stiff and coarse; these are called kemp and average about 70 microns in diameter.羊毛的宽度也有很大的差别。
细的纤维，如羊毛具有约15至17微米的平均宽度；而介质羊毛平均为24至34微米和40微米的粗羊毛。
一些羊毛纤维非常僵硬和粗糙的；这些都是所谓的肯普和平均直径约70微米的。
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 built-in waviness. The crimp increases the elasticity and elongation properties of the fiber and also aids in yarn manufacturing. It is three-dimensional in character; in other words, it not only moves above and below a central axis but also moves to the right and left of the axis.羊毛纤维横截面可为近圆形，但大多数羊毛纤维往往形状略呈椭圆形或椭圆形。
羊毛纤维具有天然卷曲，内置的波纹。
卷曲增加纤维的弹性和延伸性，也有助于纱线制造。
它是三维的性质的；换句话说，它不仅将以上及中心轴的下面也向右移动的轴左。
There is some luster to wool fibers. Fine and medium wool tends to have more luster than very coarse fibers. Fibers with a high degree of luster are silky in appearance.有光泽的毛纤维。
细中羊毛往往比很粗纤维较多的光泽。
与光泽程度高纤维的外观光滑。
The color of the natural wool fiber depends on the breed of sheep. Most wool, after scouring, is a yellowish-white or ivory color. Some fibers may be gray, black, tan or brown.的天然羊毛纤维的颜色取决于羊的品种。
冲刷后，大多数毛，是淡黄色的白色或象牙色。
一些纤维可能是灰色的，黑色的，褐色或棕色。
The tenacity of wool is 1.0 to 1.7 grams per denier when dry; when wet, it drops to 0.7 to1.5 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 end-use product will give commendable wear and retain shape and appearance. Fiber properties such as resiliency, elongation, and elastic recovery compensate for the low strength.羊毛的强度是1至1.7克/否认干燥时；当湿，它下降到0.7至1.5克/天。
与其他许多纤维相比，羊毛是弱的，和这一弱点限制了纱线和织物结构，可满意的种类。
然而，如果生产的最佳重量和类型的纱线和织物，最终使用的产品会给值得称道的磨损和保持形状和外观。
如弹性纤维，拉伸性能，和弹性恢复补偿低强度。
Wool has excellent elasticity and extensibility. At standard conditions the fiber will extend between 20 and 40 percent. It may extend more than 70 percent when wet. Recovery is superior. After a 2 percent elongation the fiber has an immediate regain or recovery of 99 percent. Even at 10 percent extension, it has a recovery of well over 50 percent, which is higher than for any other fiber except nylon.羊毛纤维具有优良的弹性和可扩展性。
在标准条件下，将20和百分之40之间延伸的纤维。
它可能会超过百分之70时，湿。
康复优于。
百分之2伸长的纤维具有立即恢复或恢复后百分之99。
即使在百分之10的延伸，它具有超过百分之50的回收，这比其他任何除了尼龙纤维。