Raw materials for the warping of synthetic fibres require well-controlled processes in chemical plants. Contamination by foreign matter is therefore very rare. However, synthetic yarns such as polyester may have different fibre properties with different brightness. Mixed yarns can cause defects in the following processes throughout the production chain. Today, the visual inspection of errors that require this cost still requires a lot of time and intensive labour. The cooperation of these two companies revealed impressive results.
Different Brightness in Different Fibres
“We use many different polyester fibers in our spinning mill.” says Sendjaja Halim, who is responsible for the Superbtex Group PT yarn manufacturers. And he adds; “Dull, Semi-Dull, Bright and Super Gloss is the typical fibre properties we use, and they all have a different brightness.” The difference is barely visible when looking at the spun yarn. As an alternative to direct visual inspection of the coils, the inspection can be performed by illuminating with ultraviolet light. But even then, it's hard to see the difference. If the inspection is carried out after the winding process and the wrong thread is close to the inside of the cone, it appears hardly even under ultraviolet light. In addition, visual inspection requires very intensive labour and is therefore expensive. Mixed yarns may lead to defects in the following processes, for example, throughout the dyeing chain during the dyeing process.
Cleaning of Foreign Matters with Brand New Features
When spinning polyester yarns, yarn cleaners are often used only to eliminate thread-related yarn faults, monitor hairiness and defects, and provide the appropriate yarn count. Since raw material originates from a well-controlled source (chemical process), there is usually no need for foreign material detection in polyester spinning. However, the different brightness problem described above can be solved by installing the YarnMaster ZENIT + with YCM YarnMaster with the yarn clearer. New functions have been developed to detect and eliminate very small colour and colour changes in mélange yarns.
Because of the varying brightness of the different fibre properties used in polyester spinning and winding, Loepfe introduced the idea of testing the new feature at the Superbtex spinning mill PT because of the different amounts of matting agents used in the production. Incorrect coils were installed during the tests. Sendjaja Halim comments on the promising results as follows: “We were able to detect all the wrong brightness coils.”
Efficient Results
The use of new OffColor detection of polyester yarns has been extensively tested in PT. The detection of 100% false coils in the winding process can guarantee excellent results in terms of yarn with different brightness. Loepfe's new OffColor detection feature of YarnMaster ZENIT +, enables the intensive work on coils and therefore expensive visual inspection.
