A study on the influence of a surface-contacting spinning strand on yarn appearance during sirofil spinning

Ring spun yarn hairiness can be reduced by such methods as spinning with a contact surface and Z-twisting the staple strand in a “left diagonal” yarn path (denoted as LDP). Actually, the LDP method already exists in sirofil spinning technology. In this study, mechanism analysis of controlling and trapping staple fibers is conducted theoretically for sirofil spinning with a contact surface. Analysis reveals that contacting with a rubber surface leads to deformation of the straight sirofil spinning strand; this can better the tension and twist distribution on the right-hand component of the sirofil spinning triangle to improve LDP sirofil yarn appearance. Related experiments are also carried out to validate the theoretical analysis. Online pictorial investigation confirms the deformation of the straight sirofil composite yarn once it contacts with a rubber surface. Experimental results show that the lower weight loss and smoother appearance are bestowed upon LDP sirofil yarn spun with a rubber contact surface, which agrees well with corresponding theoretical analysis.