Fibre Migration in Ring-Spun Yarn
topic
Fibre migration is the radial displacement of fibres between the yarn core and surface during twisting, caused by tension differences across the spinning triangle. Fibres at the triangle periphery (higher tension) migrate inward; core fibres eventually move outward. Migration is characterised by the migration intensity (I) and migration frequency (cycles per mm), measured by tracer fibre techniques using coloured fibres. Higher migration improves yarn cohesion and tensile strength by interlocking fibres across layers.
Role
Fibre migration is the structural mechanism that makes ring-spun yarn stronger than simply twisted fibres. Understanding migration explains why ring-spun yarn has 15–25% higher tenacity than equivalent open-end yarn (which has no true migration), and why compact spinning further improves strength by increasing migration intensity. This knowledge justifies premium pricing for ring-spun yarn in strength-critical applications.