This phenomenon generally occurs for three reasons. They are raw, woven and dyed. When the spandex phenomenon occurs after dyeing and finishing, the cloth sample should be disassembled and the damage of spandex should be carefully observed. If the cross section of the spandex yarn is zigzag, it means that the spandex yarn is damaged before dyeing and finishing, and the spandex breaks when the fabric is stressed during the dyeing and finishing process; if the span cross section of the spandex yarn is spherical, it is because the spandex yarn is dyed Time. There is a problem with the quality of the weld or the spandex itself.
1 Raw material problem
Different spinning methods have different properties of spandex. For example, dry spinning spandex has good elongation and slightly poor recovery rate, while wet spinning spandex is the opposite, with poor elastic elongation but better response rate. Therefore, when using different brands of spandex yarn, we must first understand its characteristics, and then appropriately adjust the amount of spandex yarn during weaving to avoid the phenomenon of spandex breaking due to weaving.
In addition, spandex is produced in different ways, and its structure is also different. Spandex looks like a single filament on the surface, but it is actually composed of multiple filaments. For example, Hyosung brand 4.4 tex (40 D) spandex consists of three monofilaments. If one of them is broken during weaving, it is not easy to find. This requires the worker to press the fabric hard on the opener and carefully check the fabric for small bright spots. If there is, there may be a spandex phenomenon.
Spandex is very sensitive to temperature, low temperature will reduce the strength of spandex, especially in the north, the workshop should maintain a certain temperature, before using the spandex, put the spandex in a place with a higher temperature, open the carton package, and let the spandex warm up first.
2 Weaving problems
In order to reduce the cost, some customers blindly shorten the span of spandex, so that the spandex filament in the fabric has too much tension and is easy to break during dyeing and finishing. Therefore, the span ratio of spandex to yarn is generally controlled at about 1:3.
Spandex damage can sometimes occur during weaving. This damage is imperceptible to the naked eye after the machine is removed, but the spandex breaks when dyed and finished. For example, the surface of the
Knitting Needle is not smooth enough, which will scratch the spandex yarn, or the spandex yarn is not fed in the correct position, causing the tip of the knitting needle to pierce the spandex filament and damage the spandex, especially when weaving relatively thick spandex filament.
In addition, if the oil on the equipment drips onto the cloth, it must be handled in time, otherwise the spandex filament will break during dyeing and finishing.
3 Dyeing and finishing problems
Compared with ordinary knitted fabrics, the dyeing process of spandex plain knitted fabrics has more predetermined shape grey fabrics. The predetermined shape is that the grey fabrics are dyed according to the finished fabric width and g quality requirements and then set, and the process of spandex filament damage is great. Because the spandex temperature of spandex filament is about 135 ℃, if the setting speed and temperature of the setting machine are not good, the spandex phenomenon is easy to occur.
In addition, if the fabric is treated with biological enzymes, and then the fabric is reworked, the spandex phenomenon is also prone to occur during the dyeing and finishing process.
In short, there are many reasons for spandex breakage, but the predetermined shape of the grey fabric is the most critical, and the temperature and speed of shaping must be mastered. In addition, the width and the quality of the master should also be paid attention to. If the length of the yarn roll is long and the quality of the finished product is relatively light, we must appropriately lengthen the amount of spandex yarn when weaving, so that the spandex will not be damaged. In addition, once the process is determined, do not change the brand of spandex frequently, so as to ensure the quality of spandex. In addition, the determination of spandex content should not be based on other factories, but to explore their own experience according to their own use of spandex yarn
