How to distinguish cashmere from wool

Due to the high-grade nature of cashmere products and the popularity of cashmere products, some manufacturers, in order to obtain high profits, mix wool fiber into cashmere and double-sided cashmere products to reduce costs and deceive consumers. For ordinary consumers, it is impossible to effectively identify cashmere fiber and wool, and they must rely on the corresponding testing institutions, only professionals With the help of microscope, the identification of fiber surface morphology can be carried out, so the market needs the effective identification and supervision of textile testing institutions for cashmere products. In the field of fiber detection, the identification of cashmere fiber and wool is recognized as a technical difficulty. For a long time, researchers have been devoted to the identification of cashmere fiber. Cashmere fiber and wool have the same structure and chemical properties. It is because of the "same" between wool and cashmere fiber that it is difficult to distinguish and identify by ordinary combustion method, chemical dissolution method and other general methods

At present, the most effective method is microscope. How to identify fibers by microscope to obtain accurate results? It is introduced as follows:

1. Fiber analysis workers need to observe the scale structure and overall morphology of the two fibers to distinguish cashmere and wool by optical microscope. Different from wool, the surface scale thickness of cashmere fiber is thinner than that of wool, and the wool scale is thicker and inlaid. Moreover, the density of scale covered wool is smaller than that of wool, so the handle of cashmere fiber is different from that of wool: the handle of cashmere fiber is smooth, while that of wool is relatively rough. In 1983, Kush and ARNS observed that the thickness of wool tip scale edge was significantly larger than that of cashmere fiber, which was an important discovery. Before that, microscopic examination was mainly based on the difference between the length of scales.

Later, Wortmann continued to observe the scale thickness of 29 kinds of fibers, including wool, Chinese cashmere, Iranian cashmere, Afghan cashmere, Mongolian cashmere and mohair, alpaca wool and camel hair. Finally, a conclusion is drawn through observation: if the scale thickness of a fiber is greater than 0.55 μ m, it should be regarded as wool; and the scale thickness of special animal fiber including cashmere should be less than 0.55 μ M. The scale thickness of wool fiber should be greater than that of cashmere fiber, which provides a strong proof for the workers who use microscope to analyze the fiber.

2. Because the scale of cashmere is thinner than that of wool, under the microscope, the light transmission performance is good, the light transmission is uniform, the fiber brightness is uniform, without shadow feeling and protuberance; while the scale of wool is thick, the light transmission is uneven, and the wool is dry, with shadow feeling and protuberance.

3. Under the microscope, the scales of cashmere fiber cover the hair dry tightly, with small warping angle, which is relatively smooth and flat; however, due to the thick scale of wool, the warping angle is large, and the surface protrusion is more, so it lacks smoothness.

4. Cashmere has longer scale length, larger spacing, smaller density than wool, and smaller friction coefficient between scales, so its cashmere shrinkage after washing is better than that of wool, while wool is worse.

5. Cashmere fiber is uniform, rarely twisted and deformed, while wool fiber is uneven and twisted more.

6. The curl of cashmere is smaller than that of wool because the positive partial cortex is distributed on both sides.