Positive Yarn Feed Systems and Tension Control
topic
Positive yarn feed systems on circular knitting machines use feed rollers driven at controlled speed to deliver defined yarn lengths per revolution to each feeder position regardless of yarn package tension variation, with individual feeder speed adjustment enabling per-feeder stitch length control and multi-yarn construction capability for plaiting, laying-in, and float-pattern structures requiring different yarn consumption rates at different feeders.
Role
Maintains consistent stitch length and fabric weight across all feeder positions by eliminating the yarn tension variation from package unwinding that would cause stitch length variation and fabric weight bars if yarn were supplied under simple balloon tension, with positive feed system uniformity across all feeders being the primary determinant of circular knitted fabric weight and stitch length consistency.