In the application of spandex yarn, wire breakage is a common problem and an important factor affecting the quality of fabrics. This paper analyzes the reason why spandex fiber breaks in the weaving process.

1.Falling broken wire of spandex yarn

Edge falling and wire breaking mainly refers to the wire breaking caused by the small unwinding tension on the surface of spandex yarn and the small friction between wires. When the unwinding speed is relatively slow, it falls off due to the side tension. In this case, there are usually orbital wires, which are usually used in the application of cotton cored and mechanically coated wires.

2.Overlapping broken wire of spandex yarn

Lap winding broken wire refers to that during the unwinding process of spandex yarn, the next layer presses the wire of the previous layer or the upper layer brings up the lower layer to form lap winding to produce broken wire. The main reasons for this broken yarn are: First, the winding angle is set unreasonably during spandex spinning, resulting in yarn pressing; Second,Improper choice of oiling agent and strong adhesion cause the upper silk to lift the lower silk.

3.Reverse winding broken wire of spandex yarn

Broken wire in reverse winding refers to that the unwinding tension of spandex yarn is too large during the unwinding process, which exceeds the unwinding stretching force. When the unwinding speed is relatively fast, the reverse winding forms a broken wire. Common manifestations and causes of broken wires in reverse winding are as follows:

a.The reason for the anti winding broken wire at the bottom of spandex stored for more than 3 months is that with the increase of storage time, the combined effect of oil volatilization, moisture absorption and its shrinkage will harden or even agglomerate the bottom.

b.The reason for the reverse winding broken wire on warp knitting or high-speed air bag machine with the unwinding speed of more than 300m/min is that the fast unwinding speed of spandex and the short buffer time of the silk path make it easier to produce reverse winding broken wire.

c.It is not targeted. For example, when the spandex used in the cotton core is applied to the empty bag, the reverse winding broken wire occurs, because the unwinding speed of the cotton core is slow and the draft is large, and the manufacturer usually increases the unwinding tension to avoid edge falling. When applied to the empty bag, because of its fast unwinding speed, it is not often easy to produce reverse winding broken wire.

d.The reason for the anti winding broken wire on the warping pan head with long service time is that the spandex will be further stretched during warping, and the storage is easily affected by the external environment, while the unwinding speed of lace is very slow, and the service time will be longer than 1 month, so the probability of anti winding broken wire is greater.

4.Drafting broken wire of spandex yarn

Drafting broken wire refers to the broken wire when the customer's process requirements exceed its bearing capacity or the equipment is abnormal when spandex yarn is applied. The common manifestations and causes of drafting wire breakage are as follows:

a.Spandex was damaged and broken due to abnormal equipment.

b.The reason for the drafting broken wire caused by excessive drafting in the later process is that it has reached its stretching limit.

c.For example, when knitting 4.44tex (40D) spandex and 15.56tex (140D) polyester on a 28 stitch /25.4mm circular knitting machine, it is vulnerable to damage due to the small needle spacing.

Spandex yarn is a new textile material with excellent comprehensive properties. In its application, the problem of wire breakage is very common, which generally includes two aspects: wire breakage in the weaving process and wire breakage on the cloth surface. Understanding the causes of wire breakage of spandex fiber in the weaving process is conducive to making better use of this kind of material.