The mechanism of hairiness reduction in offset ring spinning with a diagonal yarn path

Reducing yarn hairiness on a ring spinning machine generally involves an investment and ongoing process cost. Although conceptually successful, the cost factor associated with existing technologies has led to exploration for new ways of reducing hairiness. Offset spinning is an outcome of one such novel initiative in which the spinning triangle geometry is altered by diagonally offsetting the yarn path during spinning. This technique has been reported to reduce hairiness but a consensus on a specific direction of offset (left or right) remains pending as its underlying mechanism is still not completely understood. In this study, we developed an experimental setup to image a spinning triangle geometry in detail and observed the effect of offsetting its shape on fiber path. It was found that the direction of offset (left or right) in combination with a specific twist direction (S or Z) can result in a complete change of yarn twist configuration (Archimedean or Fermat's spiral), which ultimately controls hair generation tendency during spinning. On the basis of agreement between imaging observations and hairiness parameter results obtained from yarns spun with different offset conditions, a mechanism of hairiness reduction and preferred direction of offset is proposed.