Page 27 - August-September-2017

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Eliminating core yarn defects

missing and off-center cores

Dyed fabric comparisons highlight the effect
of yarn with off-center core.

Defect-free yarn after dyeing Yarn with off-center core after dyeing

Core yarn producers have to deal with two for other aspects. In this case, the mill opted for a
potentially damaging extra quality issues: areas tolerance level of two core issues per kilometer.
where the core component is either missing or
off-center within the outer wrapper yarn. A case The event report clearly indicated both the type
study from a spinner in South East Asia here and dimensions of each core defect. Yarns
provides an excellent illustration of how these reported to have missing or off-center core above
problems can be overcome using the USTER® the set limits were cut by the clearer. Subsequent
QUANTUM 3 Anniversary Edition yarn clearers. examination of the rejected bobbins confirmed
either missing or off-center core in those bobbins.
The spinning mill produces a Ne 16 yarn from
100% carded cotton for weaving, with a core As a double-check, yarn from the rejected bobbins
element of 70D spandex. As with many core yarn with off-center core were then dyed, and a
spinners, this mill was facing claims and significant difference in appearance was noted, as
complaints from customers because of missing illustrated in the comparison pictures.
and off-center core. The mill then installed the
unique Core Yarn Clearing option with USTER® The mill’s experience showed that hardly any of the
QUANTUM 3 Anniversary Edition, with the aim of clearer cuts related to core issues were found not
eradicating these problems through an investment to have core defects, demonstrating that
providing rapid payback. unnecessary cuts are at an absolute minimum
when settings are correctly optimized.
From the system’s article settings options, the mill
first selected core yarn and then – after a couple of The case study is further evidence that the
trials – an optimum clearer setting. USTER® QUANTUM 3 Anniversary Edition – with
its advanced capabilities for detecting core yarn
The system’s alarm function was set to eject any defects – is a highly-effective and reliable yarn
spinning bobbin with too many core-related quality assurance system for
problems, as well as maintaining regular settings spinning mills.

August/September 2017