Influence of Yarn Twist Characteristics on Fabrics

Twisting is a necessary means to grow the yarn on the short fiber side. The twisting of the yarn is to make the two sections of the sliver rotate relative to each other. At this time, the fibers in the sliver that were originally parallel to the yarn axis are inclined into a spiral. The twist direction and twist of the yarn and the combination of the twist direction and twist of the yarn in the fabric have a great influence on the physical properties and wearability of the product.

1. Physical and mechanical properties

By twisting the yarn, the cohesion between fibers increases, the breaking strength and elongation at break increase, and the wrinkle resistance and wear resistance also increase, but the twist cannot exceed a certain value, otherwise the textile The fabric is stiff, the folded edge is easy to break, and its strength is reduced, and the dye is difficult to penetrate, and it is easy to fade or “whiten” after dyeing. Different yarns have different requirements for twist.

Generally, under the premise of meeting the strength requirements, the smaller the twist of the yarn, the better, because the increase of the twist will make the yarn feel harder, the elasticity will decrease, and the shrinkage rate will increase. For example, the filament yarn should be twisted as little or no twist as possible; the twist of woven and knitted pile fabrics should be smaller to facilitate the raising; the twist of the warp should be appropriately increased to adapt to the high tension and friction of the weaving process. requirements; hemp yarn fabrics are required to have a crisp and smooth feel, and the twist of the yarn should be larger.

In addition, the arrangement of warp and weft yarns in the fabric structure: the same twist and different twists will also be quite different.

This is because when the warp and weft yarns are arranged in the same twist, the warp direction is the same on the contact surface of the warp and weft yarns, so that the yarns of the two systems of warp and weft can be embedded in each other, resulting in an increase in the cohesion force. Insertion also makes fabrics with the same twist of yarns appear thinner than those with different twists, so fabrics that are fluffy, thick and soft should choose different twists. At the same time, since the direction of the fabric with the same twist of the yarns is just 90 degrees perpendicular to the front, the reflection of the yarns is inconsistent, resulting in a lower luster than the different twisted fabrics.

Some fabrics with hidden stripes and hidden lattice effects on the surface are woven by using the same and different twists of luster inconsistency. The twist direction is also related to the twill direction of the twill fabric. For example, when the warp is Z twist, the left twill is often used; when the warp is S twist, the right twill is often used.

Second, the use of performance

The twist has an effect on the volume weight and diameter of the yarn. The twisting effect reduces the yarn diameter and increases the tightness. The same yarn gap increases the unit weight. In the twisted yarn, the space between the fibers becomes smaller, and the original air in the space is squeezed out. The size of the fiber thermal insulation mainly depends on the air content.

The space between fibers is also related to the moisture absorption and air permeability of the fabric. The fabric with large space has good permeability and fast moisture absorption and air permeability. transperation wax emulision, Twisting improves the pilling resistance of the yarn. The greater the twist, the greater the friction and cohesion between the fibers, and it is difficult for the fiber head to slide to the surface of the fabric, and it is difficult to entangle and pill. In addition, the greater the twist, the tighter the yarn and the better the hook resistance.

Twisting can also increase the bending stiffness of the yarn, reduce the softness of the fabric, and make the drape feel worse. Because the more fiber tips exposed on the surface of the yarn, the better the fiber softness. Such as towels, underwear and cotton socks, the twist should be smaller to make the finished product feel soft and comfortable.

The twist of the yarn is related to the surface texture of the fabric. The so-called glossiness is actually determined by the amount of reflected light from the object that can be seen by the naked eye. Taking cotton yarn as an example, when the combed cotton yarn is untwisted, the light is reflected on the surface of each fiber, and the surface of the yarn appears dark and dull. When the twist of the combed cotton yarn reaches a certain value, the light is reflected from the relatively smooth surface. The amount of reflection reaches the maximum value.

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However, when the twist continues to increase, the light is diffusely reflected and absorbed between the convex and concave surface of the yarn, so the reflected light weakens as the twist continues to increase, so the surface of the fabric woven with high-twist yarn is soft and has a soft feel. Also harder.