#Spinning
Systematic quality management is a priority
One reliable safeguard against such systemic failures is the USTER® AFIS PRO 2 fiber testing instrument, which can act as an early warning of individual quality defects and an indicator that the overall quality structures are not working.
Quality-conscious spinners are today generally well-versed in making use of valuable tools such as USTER® TESTER 5 for laboratory controls and USTER® QUANTUM 3 as the last-stage failsafe in the winding room. Most mills will have put in place a series of instrumental checks, enabling unacceptable fault levels to be detected and rectified.
Sometimes, though, these monitoring actions will actually highlight the need for cohesive structures throughout the mill, to establish systematic quality management – and ensure it is applied continuously as a priority strategy.
A typical scenario, in this case from a Chinese spinning mill, illustrates the point:
A box of bobbins waits in the laboratory for testing. Zhang Qiang is the manager of an established spinning mill in Xingjiang province. He has recognized an unusual high quantity of bobbins being ejected at the winder. The Ne 34 cotton yarn obviously contains too many yarn faults compared with the settings from the USTER® TESTER 5. “Thanks to the 100% monitoring of the produced yarn using yarn clearers at winding, no off-quality yarn will be delivered to the customer,” says the mill manager, pleased at this apparently satisfactory outcome.
In detail, the data from the USTER® QUANTUM 3 clearers shows irregularities for thick places in classes C3, C4, D3 and D4 and indicates a high level of unacceptable thick place cuts, indicating changes compared to the measured fiber characteristics. The whole YARN BODYTM also appears to be wider than normal.
There is also bad news, however. The fact is that the problem should never have gone so far as the winding machine. From the USTER® TESTER 5 results, and based on his own knowledge and experience, Zhang Qiang assumed that the quality problem started at carding, or even earlier during the bale laydown.
This mill’s systematic quality management starts at carding, testing the sliver on a weekly basis. “I know that the correlative results of the AFIS® will reveal that the problem could have been recognized already at this stage of the production process,” says Zhang Qiang, before looking for the files. He was correct: the USTER® AFIS PRO 2 reports show a deviation of more than 7% for the short fiber values. The origin of the problem is now confirmed. And, of course, someone should have checked this report before the damage – a lot of wasted yarn – had the chance to occur.
So, where does the blame lie? It’s not easy to solve the problem of tight resources in a spinning mill. But setting the right priority on systematic quality management could help to get the most value from available resources. It’s clear also that spinning mills would be well-advised to take AFIS® test results as a pre-indicator or early-warning system, prompting action before the yarn clearer has to provide the final, more costly, solution.
“Our mill has well-structured processes for quality management implemented and could serve as a good example for many others,” says Zhang Qiang “but the impact of a systematic quality management can only reach its full potential when it is put into practice as an absolute priority.”
