Crealet, the manufacturer of electronic warp feeding systems for weaving based in Wald, Switzerland, is this year celebrating its 20th anniversary and at June’s ITMA 2023 in Milan introduced a new fully-automated solution for the electronic warp feeding of narrow fabrics, the KAST ECR.

Crealet’s mission is to empower high-performance weaving with a consistent high-quality since minimum faults can only be achieved with optimum warp feeding. The company’s warp supply options – for beams or creels – focus on the key areas of maintaining constant warp tension and reducing thread breaks.

A warp beam does not need to be driven and warp tension is sufficient. The beam needs only to be braked to maintain correct tension. Until now this has often been accomplished with weight-loaded rope brakes but these mean the weights have to be changed as the beam diameter is reduced. The fully-automatic KAST ECR eliminates this, while also keeping warp tension constant from full to empty beam.

With KAST ECR, warp tension is monitored with load cells or alternatively with indicative distance sensors. The control unit shows either the tension or the position of the pendulum. Many functions of the established Crealet BLDC control unit were additionally adopted for this control method.

Background

Crealet was formed through a management-buy-out from Willy Grob AG at a time when weaving machine manufacturers were integrating their own electronic warp let-off systems and a growing need for warp let-off controls with specific customised solutions was identified by Crealet founders Walter Wirz and Leo Kuster.

With its KAST solutions, the company’s aim was to offer a universal control system suitable for different applications and achieve the high warp tensions often impossible on weaving machines featuring integrated warp let-off. The UKAST, for use in wide weaving for ground and warp beams in high positions, as well as for warp beams in free-standing warp beam frames, was introduced in 2008.

Crealet soon built a reputation for developing systems to replace older control units, or to meet the requirements of new applications such as ribbon weaving. A wide variety of solutions was developed including selvedge yarn feeders to prevent waviness at fabric edges and feeders for weaving carbon or tyre cord fabrics.

More recently, there has been a demand for a servo control to offer high precision and to approach and hold defined positions without torque loss. With the control of Kast Ergo, it’s now possible for weavers to switch to electronic from mechanical fabric take-off.

A further Crealet innovation, Linked Motion Control, was first introduced at ITMA 2019 in Barcelona, signalling a new era of warp tension measurement. This load cell sensor system enables a setpoint to ben entered at the control unit, ensuring that the warp tension settings are highly reproducible.

The latest Crealet controls are designed to allow direct access to the warp let-off system via a remote maintenance tool. Quick and efficient support is guaranteed, without the need for a specialist on-site, saving both time and money.

No single KAST solution will ever be ideal for all warp beams and weaving machine types. Crealet takes the view that ‘good enough is not enough’ with its controls programme, although its portfolio extends beyond control devices to include the entire mechanical design of the system.

“Only when all components are perfectly coordinated can a system work perfectly,” says Walter Wirz.

www.crealet.com