Open-end, ring and air-jet yarn: how they differ

Every spinning system does the same basic job: it draws fibres into a thin strand and then binds it together — usually by twisting, and in air-jet spinning by wrapping. How the strand is bound changes the structure of the yarn — and with it the feel, strength and cost of the fabric.

Ring spinning

The oldest of today’s systems. Sliver is first drawn into a finer strand called roving, then drawn again and twisted by the rotating spindle, while a small traveller, dragged around the ring by the yarn, does the winding. Ring yarn is the strongest and softest and can be spun very fine, but the process is slower and has more steps. Combed ring yarn, with the short fibres removed, goes into premium garments.

Open-end (rotor) spinning

Here sliver goes straight to the spinning unit, skipping the roving stage. An opening roller separates it into individual fibres, which collect inside a rotor turning at very high speed and are twisted into yarn. Open-end is much faster than ring spinning and the yarn is very even, though harsher to the touch and typically about 10–30% weaker than comparable ring yarn, with the gap widest on long-staple cotton. It is the workhorse for medium and coarse counts: above all denim and workwear.

Air-jet spinning

A jet of compressed air wraps the outer fibres around a core of parallel fibres. Air-jet machines have the highest delivery speed of the three: up to 600 m/min, against 350 for rotor and 40 for ring. The yarn has very low hairiness, so fabrics look clean and resist pilling. It works especially well with viscose and blends.

No system is “best”. The right choice depends on the fabric, the count and the price the product has to hit.