New developments for online quality control in high speed false-twist texturing

Yarn texturing is currently controlled mainly by the online measurement of yarn tension behind the twisting unit. A previous investigation shows that measuring yarn tension at the inlet of the twisting unit may offer detection of uneven dyeing in the texturing process. A non-contact method of measuring was essential to avoid influence on the twisting process. The sensor developed uses a camera connected to a Fraytec III system. This system uses the camera images to detect filament breaks, makes a recording in a digital image format and then extracts and transforms the data in the image files. A subsequent process can describe the yarn damage and calculate parameters. The automatic and therefore objective classification of yarn damage is possible with this successfully tested device.