What are the effects of twisting on the properties of yarns?

The effects of twisting on the properties of yarn are mainly as follows:

(1) Effect of twisting on the elongation of yarn

1. Influence on strength For the flawless strip, its strength is very low. As the degree of twisting increases, the friction between the fibers increases, the number of slipped fibers decreases, and the twist is made. The unevenness of the strength is improved, so the strength increases as the enthalpy coefficient increases. However, as the twisting coefficient increases, the preload of the fiber due to the tilting torsion increases, and the axial component force decreases. Therefore, the result of the combination of the former favorable factor and the latter unfavorable factor causes the yarn to be When a certain coefficient is reached, the maximum value is reached. If the twist is continued, the yarn strength will decrease. The 捻 coefficient at this time is called the critical 捻 coefficient.

2. Effect on elongation at break The elongation at break of the yarn consists of three parts:

(1) Slip elongation (between fibers)

(2) The fiber itself is stretched by force

(3) Elongation caused by the yarn twist angle and the diameter becoming smaller.

In the range of the normal enthalpy coefficient, the general trend is that the elongation at break increases with the increase of the enthalpy coefficient.

(2) Effect on the weight and diameter of the yarn

When the yarn density and diameter are large, the fibers in the yarn are dense, and the interfiber spaces are reduced, so that the density of the yarn is increased and the diameter is decreased. When the twist factor is increased to a certain extent, the compressibility of the yarn is reduced, and the density and diameter are not changed much. On the contrary, the fiber is slightly thickened due to excessive tilting of the fiber.

(3) Effect on the wear resistance of the yarn

Within a certain range, the yarn wear resistance increases as the enthalpy coefficient increases.

(4) The influence of other properties of the yarn

(1) gloss;

(2) feel;

(3) Strip uniformity and so on.

When the twist coefficient of the yarn is large, the fiber has a large inclination angle, the gloss is poor, and the hand feel is hard, and the mass of the strip gradually decreases with the increase of the twist coefficient, showing a deterioration trend.