This is a yarn package defect. This defect gets occurred during yarn winding process. 'The patterning or ribbon formation (Ribboning ) can be defined as a yarn package defect to be occurring during yarn winding process, in which the yarn coils get laid on the top of the previous yarn coil'.
In other words, we can say that the yarn coils follow similar path repeatedly during winding. This repeatedly continuous yarn coils path causes patterning or Ribboning ( ribbon formation) in the yarn package getting wound.
At the starting of winding, the diameter of empty package is less than traverse drum. As the winding gets begins, the package diameter increases rapidly. When the package diameter gets equal to traverse drum, the patterning zone gets started. The ratio between rotational speed of traverse drum and package gets equal to whole number (1). As soon as diameter of package gets increased the patterning zone gets ended. This kind of situation created every time when the ratio between rotational speed between traverse drum and package gets equal to an integer ( whole number. The patterning can be classified as below:
When the package diameter gets relatively large, the rate of increase of package diameter gets slow. We can say that diameter change takes long time. In this stage, the patterning results for long time.
This kind of patterning results at the starting of winding. Since the rate of change of package diameter gets very fast at the time of starting, so that the patterning persist for very short period.
ANTI PATTERNING DEVICE:
If a yarn package has patterning or Ribboning defect in it, the yarn unwinding gets difficult during uses of this kind of package. A lot of end breakages get occurred during yarn unwinding. There are different types of anti patterning ( Ribboning ) devices used to prevent the patterning or Ribboning defect in the yarn package. The some of anti patterning systems being used in different winding machines are given below: