Weft Control

Loepfe’s unique weft control technology includes the short weft detector WeftMaster KBW for projectile weaving machines, whilst the weft thread brake WeftMaster SFB is designed for all kind of yarns and operates with a minimum of weft thread tension. To complete the weft control set, all kind of weft faults are detected by the weft stop motion WeftMaster SW.

Weft CONTROL In Weaving Machines

Weaving is among the processes, which have been automated very early during the Industrial Revolution. Ever-since modern weaving became faster, and the quality of the final woven fabric became better. Today, modern machines are able to produce fabrics at a very high output. In addition it is possible to weave extremely thin threads. For example clothes for screen-printing use threads with a thickness of only 16 µm, for microphones and speakers in smartphones 7 µm thin threads are used. For comparison: A human hair has a thickness between 40 µm and 120 µm. Another demanding weaving application is the production of lingerie, where no stress of the yarn, no gaps in the fabric, and no stripes in the final product are allowed.

The importance of weft control

The above-mentioned applications are very challenging for the control mechanisms in the weaving machine. The insertion of the weft thread into the shed has to be controlled thoroughly. A broken weft or a weft, which is too short to reach the other side of the shed, has to be detected. Otherwise a so-called mispick occurs, and stripes would be visible in the fabric. Depending on the application, this is not only an optical issue – there might also be deviations in the function of the fabric. Another crucial parameter in the weaving process is the weft thread tension. This parameter is particularly important, when yarns with low tensile strengths are used. To high tension stress can result in an uneven fabric, or – in worst case – in weft breaks.

Sensors and systems for all type of looms

Weaving machines are divided in three categories: air-jet, rapier, and projectile looms. Loepfe offers solutions for all types of machines, which control a perfect weft insertion and guarantee the fast detection of faults in the process. The result is the highest possible quality of the final fabric.

Our customers know – with Loepfe their production is under control.