ENHANCING TWIST UNIFORMITY IN WRAP YARN SPINNING USING A V-GROOVED ROLLER: A THEORETICAL ANALYSIS

This study presents a theoretical investigation of a novel wrap yarn spinning method incorporating a V-grooved roller positioned immediately after the front drafting rollers to address the persistent challenges of uneven twist distribution and excessive roller wear in conventional ring spinning systems. In traditional wrap spinning, yarn passes through multiple contact points between the roller nip and ring-traveler system, creating a non-twist section and twist gradient that compromises yarn strength and uniformity. The proposed V-groove configuration guides the emerging fibre bundle to a single convergence point—the groove apex—where twist is concentrated and uniformly propagated along the yarn length. The groove acts as an effective twist stopper, preventing twist migration toward the drafting rollers. Key geometric parameters including apex angle (optimised at 60–90°), vertical distance (below 20 mm), and horizontal offset (within 30 mm) were identified as critical factors influencing fibre compression and twist effectiveness. Theoretical analysis predicts that twist variability, typically 5–10% in conventional systems, can be reduced to 2–4% with the V-groove approach. Anticipated improvements include higher yarn tenacity, better evenness, reduced hairiness, enhanced abrasion resistance, and extended roller service life. The system can be retrofitted to existing ring spinning frames with minimal modification, offering a practical, cost-effective solution for industrial implementation.