What Are The Main Factors Affecting The Strength And Elongation Of Silk Yarn?

　　The factors affecting the strength and elongation of silk yarn are mainly the fiber properties of silk yarn and the structure of silk yarn. The strength and elongation of blended yarn are also closely related to the difference in properties of blended fibers and the blending ratio. Temperature and humidity The impact of external factors such as strength and test conditions on the strength and elongation of silk yarn is the same as that of fibers. Next, follow the polyester yarn factory to learn more about it.

　　fiber properties

　　Fiber length, linear density:

　　When the fiber length is longer and the fiber is thinner, the friction resistance between the fibers in the yarn is larger and it is not easy to slip, so the yarn strength is higher.

　　When the fiber length uniformity is good and the fibers are thin and uniform, the yarn will be even and dry, and the weak rings will be less but not obvious, which is conducive to the improvement of yarn strength.

　　Fiber strength:

　　When the strength and elongation of the fiber are large, the strength and elongation of the yarn are also large; if the fiber is strong and the unevenness of the elongation is small, the yarn strength is high.

　　Surface friction properties of fibers:

　　When the fiber surface friction coefficient μ increases, the sliding resistance between fibers increases, the slip length lc decreases, the proportion of slipped fibers decreases, and the yarn strength increases. Increasing the crimp number of fibers can increase the sliding resistance between fibers.

　　silk yarn structure

　　(1) The influence of the short fiber yarn structure on its strength and elongation is mainly reflected in the twist.

　　When the twist coefficient increases, the frictional resistance between wood fibers increases, and it is not easy to slip. This is a positive side for the strength of staple fiber yarn. The effective component force in the yarn axis decreases, the fiber breakage in the yarn does not increase at the same time, and the diameter of the silk yarn increases when the fiber is inclined, all of which are unfavorable factors for the relative strength of the silk yarn.

　　(2) Impact of joint stock

　　The combination of single yarns makes the strands (ply yarn) evenly dry, and there is contact between the single yarns, which increases the cohesion between the outer fibers of the single yarns; the strength of the strands is greater than the sum of the strengths of the single yarns.

　　(3) Arrangement of fibers in spun yarn

　　The strength of rotor-spun yarn is lower than that of ring-spun yarn: in rotor-spun yarn, there are more irregularly arranged fibers such as folded, curled, and circled, and fewer fibers are normally transferred, resulting in poor contact between fibers and fibers, more slipping fibers during stretching.

　　(4) Bulked yarn

　　The tensile breaking strength of the bulked yarn is smaller than that of the traditional yarn, but the elongation at break is larger.

　　Structural characteristics: Two kinds of fibers with very different heat shrinkage are used to blend and then heat shrink to make the fibers with high shrinkage in the sliver fully retracts, and at the same time force the normal fibers with small heat shrinkage to compress and wrinkle along the yarn axis. Exhibits bulking properties.

　　Tensile fracture process: when the bulky yarn is stretched, the number of fibers bearing external force is small, and the tension of each fiber is uneven. When stretched at first, only a small part of the fiber bears the external force, while the other fibers buckle and relax. After the former fiber is broken, the latter fiber straightens and bears the tensile force until the whole breaks.

　　(5) textured yarn and elastic yarn

　　Relying on various shaping methods, each fiber is made into a helical spring shape or a crimped directional wrinkle curve.

　　During the considerable period of stretching, the fiber is gradually straightened under the condition of a small increase in the stretching force, which has a high elongation at break.