Development of yarn shape imaging system using collaborative robot for disc friction false-twist texturing machine

The contact state between yarn and the disc in the disc friction false-twisting machine affects the yarn quality. Previous studies have the contact state between yarn and disc has been discussed. However, the specific imaging methods were not suggested. In this study, we developed an imaging system that uses a collaborative robot to accurately and instantly observe the contact state. Using this system, the apparent yarn thickness, twist angle, and inclination angle on all discs within the unit were measured precisely from three directions. As a result, the apparent yarn thickness was found to be influenced by the draw ratio. Additionally, as the yarn passed through discs, twist angle increased and inclination angle of yarn decreased, confirming their interrelationship. Furthermore, it was observed that twist angle decreased downstream of the disc unit, suggesting that the contact state between yarn and the disc becomes unstable in this region. It was revealed that this system could be utilized for evaluating various disc units in future studies.