Wool mainly refers to sheep wool, which is an important raw material for the textile industry and one of the main raw materials for carpets. It has many excellent characteristics such as good elasticity, strong hygroscopicity, good warmth, no staining and soft gloss. Therefore, wool carpet is a high-grade carpet, which is expensive and gorgeous.
The wool fiber has a curled elongated column from the outside. When viewed under a microscope, it has scales on the outside, the cross-section is slightly rounded, and the coarse hair is oval, and there is a pulp, which is ideal for making wool carpet. raw material.
The cross section of wool can be divided into three levels, namely the scale layer, the cortical layer and the medulla layer. The fine wool is composed of a scale layer and a cortical layer, and has no medulla layer, and the coarse hair is composed of a scale layer, a cortex layer and a medulla layer.
1. Scale layer Also known as the epidermis layer, it is coated on the outermost part of the hair shaft and is composed of keratinocytes. It is a flaky horny tissue with roots attached to the cortex, hence the name. The scale layer has strong resistance to chemicals and enzymes, protects the cortex and reflects the luster and fluff of the wool. The scale layer can be further divided into three layers: the surface layer, the outer layer and the inner layer. The surface layer has water repellency and chemical stability.
2. Cortical layer This is the solid part of the wool, located below the scale layer, which consists of a number of slightly flat spindle-shaped cortical cells. The cortical cells, the cortical layer and the scale layer are bound together by the interstitial cells of non-protein cells, and the content is about 1%. The cortex layer sometimes contains a small amount of natural pigment. In recent years, a kind of colored wool that has appeared in the world is to use biological genetic engineering to feed sheep with certain trace elements of metals, so that the cortex contains certain natural pigments, thus changing the color of the wool. For example, feeding iron can make the sheep's hair turn light red. Feeding copper can turn the hair into blue. Now it has produced bright red, sky blue, gold and brown, etc. The carpet can be made into a pollution-free environment-friendly carpet without dyeing.
3. Medullary layer Fine wool generally has no medulla layer. The medulla layer is present in the center of the semi-fine hairs and coarse hairs. It consists of loose, air-filled, irregularly shaped keratin parenchyma cells, which are dark black in shape when viewed under a microscope. The content of the medulla layer varies depending on the type of wool, and may be continuously or discontinuously distributed, and the width and width of the distribution are also different. The wool with more medullary layers is brittle and fragile, the tensile strength and elasticity of the fibers are poor, the spinning value is low, and it is not easy to dye. Semi-fine hair has fewer medulla layers and is discontinuous, but the fibers are thicker and longer, so it is often used to weave carpets.