The mechanical properties of textile fibers should include fiber strength, elongation, elasticity, wear resistance, elastic modulus, etc.

Fiber strength: The strength of the fiber refers to the ability of the fiber to resist external damage, which largely determines the durability of textile goods.

The strength of the fiber can be expressed by the maximum strength of the fiber, which refers to the larger load that the fiber can withstand under the action of continuous increasing load until it breaks. Its legal lecturers are Newton (N) or Centinewton (cN). It used to be expressed in grams or kilograms.

Because the strength of the fiber is related to the thickness of the fiber, the strength of the fiber is not comparable for different thicknesses, so the relative strength is commonly used to indicate the strength of the fiber. Relative strength refers to the greater tension that the fiber can withstand per unit linear density (per tert or per denier). The legal unit of measurement is Niu/T (N/tex) or Li Niu /t (cN/tex). It used to be expressed in gram/denier.

Fiber elasticity: fiber and its products in processing and use, are subject to external force, and produce the corresponding deformation. When the action of external force is removed, part of the deformation of the fiber can be restored, while the other part of the deformation will not be restored. According to this characteristic of fiber dimension, the deformation of fiber can be divided into three parts, that is, when the external force is removed, this part of the deformation can be immediately restored, called rapid elastic deformation; When the external force is removed, this part of the deformation that can slowly recover is called slow elastic deformation; When the external force is removed, this part of the deformation that cannot be restored is called plastic deformation.

The elasticity of fiber refers to the resilience of fiber deformation. The commonly used index to indicate the elastic size of the fiber is the elastic recovery rate or resilience rate of the fiber. It refers to the percentage of rapid elastic deformation and slow elastic deformation of a certain time in the total deformation.

If the elastic recovery rate of fiber is high, the elasticity of fiber is good and the ability of deformation recovery is strong. Textiles made of elastic fibers have good dimensional stability, are not easy to wrinkle during use, and are more wear-resistant. For example, polyester has excellent elasticity, and the clothing made of it has the characteristics of crisp and wear-resistant.

Fiber wear resistance: fiber and its products in the process of processing and actual use, due to continuous friction caused by wear. The wear resistance of the fiber refers to the resistance of the fiber to external wear.

The wear resistance of fiber is closely related to the fastness of textile products. Wear resistance is an important index of wear performance of clothing fabric. The wear resistance of fiber is related to the macromolecular structure, supramolecular structure, elongation at break and elasticity of fiber. The order of the wear resistance of common fibers is as follows:

Nylon > Polypropylene > Vinylon > Polyester > Acrylic > PVC > Polyester > Acrylic > PVC > Wool > Silk > Cotton > Hemp > Rich fiber > Copper ammonia fiber > Viscose fiber > Acetate fiber > Glass fiber.

Elastic modulus of the fiber: The elastic modulus of the fiber is also called the "initial modulus", which refers to the stress-strain ratio at the beginning of a straight section of the fiber tensile curve. In the actual calculation, the elastic modulus of the fiber is generally obtained at a point on the load elongation curve when the elongation is 1%.

The elastic modulus of the fiber indicates the difficulty of the fiber under small load, which reflects the rigidity of the fiber and is closely related to the performance of the fabric. When other conditions are the same, the elastic modulus of the fiber is large, then the fabric is stiff. On the contrary, the elastic modulus is small, the fabric is soft.

Twisting is the relative rotation of the two sections of the yarn, when the fibers in the yarn that were originally parallel to the yarn axis tilt into a spiral. For short fibers, twisting is mainly to improve the strength of the yarn. The twisting of the filament can not only improve the strength of the yarn, but also produce some effect. The amount of yarn twisting and the twist of yarn in the fabric have a great influence on the appearance and performance of the product.