Special glass mini-tubes

Small format but big performance: precisely angled “Duran” mini-tubes in the weaving machine‘s weft yarn process.
Inge Keller-Höhl, SCHOTT Schweiz, Feldbach, Switzerland

A Revolution in weaving

The Swiss textile machinery manufacturer Sulzer Textil has achieved a quantum leap in weaving technology with a new multi-phase weaving machine for standard fabrics. High precision “Duran” glass mini-tubes ensure problem-free processing of the weft yarn.

The noise in the weaving room is deafening. Standing alongside conventional looms is the revolutionary M8300. It is running on a test basis, but much more quietly than its predecessors. The difference between the conventional looms and the futuristic-looking new development is obvious even to non-specialists.

There has been no change in the basic principle of weaving for centuries. Fabrics are still produced by criss-crossing threads at right angles and all around the world, woven materials are still produced on single phase looms.

Conventional technology at the limit

Until recently, attempts to improve the technology have been based on increasing the speed of the weaving process. The weft insertion rate has been developed over several hundred years from a few meters per minute to the current rate of more than 2,000 meters per minute. This made ever increasing demands on the mechanics and the yarn. Accelerating and braking stresses the thread to the very limits of its strength, making further improvements in performance next to impossible. Not so with Sulzer Textil‘s revolutionary multi-phase system. The multi-phase weaving machine uses compressed air to insert four weft yarns at the same time. The yarn is fed synchronized into the weaving cases at 1,250 meters per minute, an incredibly fast rate. The new technology increases capacity threefold compared to conventional machines and reduces production costs up to 30 percent.

Special glass for weft yarn processing

One of the machine‘s core functions is the weft processing. Here, high precision “Duran” special glass mini-tubes by SCHOTT are a central element. The order was handled by SCHOTT‘s Swiss sales company SCHOTT Schweiz.

“Duran” proved to be the ideal material because of its good surface structure. Tests were carried out to determine the precision accuracy of curvature and the glass ends required. Another benefit was the fact that SCHOTT is in a position to mass produce the items at a constant level of high quality. The glass mini-tubes are ideal for handling the yarn because, unlike metal or plastic, they have neither edges nor other irregularities which could interrupt the flow.

The threads are carried at high speed on a jet of air through the air channels and are inserted in the weft channels. It is easy to see that the interplay between material and technology is at the very highest level. Dreaded machine stoppages as a result of poor insertion have been minimized. Stoppage occurs only once per 500,000 insertions.