by Hans Stahlecker, Maschinenfabrik Altstätten AG 

For valid reason Ring Yarn is considered the best yarn for the manufacture of fabrics. As no other it is universally suitable for all purposes.

This leading position of Ring Yarn in comparison with rotor- and air jet-yarns is even amplified by the market introduction of the so called Compact Yarns.

Which advantages do Spinners, Weavers and Knitters expect from Compact Yarns?

In order to answer this question it is first of all necessary to highlight which yarn properties – and consequently those of the final product – are desirable and which are not.

Desirable are:

• a soft, textile-like handle.
• a brilliant, clear surface.
• as far as possible a clean appearance, particularly with multicoloured or structured surfaces.
• an easy care characteristics.
• a high strength.
• a good elasticity.
• a natural overall appearance.
• a pleasant wear-feeling.

Undesirable are:      

• a harsh handle
• a dull surface
• a blurred fabric appearance
• an easy formation of pilling
• a synthetic overall impression and.
• a sticky adherence to the skin

Out of the above features the following consequences result:

Ring Yarn should get its desired strength with a minimum of twist, as this is the prerequisite for a soft handle of the fabric.

Ring Yarn should contain a minimum number of long hair (3 mm and longer) as long hair make the fabric appear blurred and blunt and because long hairs encourage the formation of pilling.

Ring Yarn should contain a sufficient number of short hairs (up to 2 mm) as these are essential for the textile character of the fabric and for a pleasant wear characteristic.

To achieve a natural lively, overall appearance, the yarn must have a certain “structure”. A completely regular and absolutely hairless yarn would be coming very close to a filament. Textiles produced from such a yarn would have a sterile character if not to say a lifeless appearance.

Summarizing it can be said: The most important feature is an as far as possible regular reduction of the long hairs. In second place follows an improvement in strength and elasticity. At the same time a certain surface structure must be maintained, which gives the final product a lively and natural appearance and texture.

The industrial manufacture of Compact Yarns began with the market introduction of pneumatic compacting devices. Pneumatic compacting devices are effective, but expensive to purchase, costly to maintain and require additional power to operate.

Pneumatically produced Compact Yarns are therefore more expensive than standard yarns and are predominantly used for luxury articles. Especially the world-wide rising costs of energy hinder, since then to a considerable degree the introduction of (pneumatic) compact spinning on a wide scale.

Following the market entry of the magnetic-mechanically operating compact spinning system RoCoS by the Swiss company Rotorcraft, the situation has fundamentally changed. This system for the first time permits the manufacture of impeccable Compact-Yarns within the cost structure of standard yarns. It has allowed to create a prerequisite for incorporating the advantages of the compact spinning system for all quality yarns, carded or combed, made from 100 % cotton, synthetics or blends.

One does not need to be a prophet to forecast today that in the foreseeable future the magnetic-mechanical compact spinning system will become the standard equipment of modern ring spinning frames.

With the market introduction of RoCoS by Lakshmi Machine Works of Coimbatore and the modernization of existing ring spinning frames by Rotorcraft of Switzerland this process has already commenced in India.