Hand visual inspection method: This method is suitable for textile raw materials in the state of loose fibers.
(1) Cotton fiber is shorter and thinner than ramie fiber and other hemp fiber and wool fiber, and it is often accompanied by various impurities and defects.
(2) The hemp fiber feels rough and hard.
(3) The wool fiber is curly and elastic.
(4) Silk is long and slender, with special luster.
(5) Among chemical fibers, only viscose fiber has a large difference in strength between dry and wet states.
(6) Spandex yarn has very large elasticity, and its length can be stretched to more than five times at room temperature.