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              bobbins. The other clearing channel focuses on   different reference lengths run parallel. This is
              full-length monitoring of the bobbins and cuts   helpful in defining the clearing limits for mélange
              defects where shade variations are identified.  yarns, which obviously contain more subtle
 Mélange yarns  Settings for this function can be input easily by   Some customers have asked why such an excellent
                                                              variations in shade than single-colored yarns.
              defining a clearing limit. The Shade Variation
              feature is then activated as soon as the yarn is
                                                              feature was not available with previous generations
              running, checking the color of the bobbin, to
              ensure no mix-up has occurred. The initial Shade   of yarn clearers. The answer is both simple and
                                                              important: Only the combination of the green and
              Variation (SV) limit is set closer than the     red LED light in parallel makes the great sensitivity
 when the slightest   Continuous Shade Variation (CSV) channel   of detection and separation possible – and only this
                                                              combination works as a reliable fallback system in
              setting, which now takes over and verifies the
 shade variation matters  whole length of yarn. With the CSV function,   case of an operator failure.























 Barré effect caused by a wrong colored bobbin  Magnified part of the defective fabric

 The growing market for colored and mélange   A customer has defined the spinner’s
 yarns brings a challenging requirement for   requirement in a simple statement: “The clearer
 spinners: shade variations are simply not   has to detect any mix-up of shades when the
 acceptable. Mélange effects typically involve   operator fails.” With this objective in mind,
 many different effects and unique designs – often   USTER organized trials in a Turkish spinning mill
 produced in small lots. This can lead to problems   to challenge the new software feature in
 when bobbins of different color shades are   detecting very slight color deviations.
 unwittingly mixed up. It can happen all too easily,
 for example when an unwary operator is feeding   Two different blends were used for this
 spinning bobbins to the winding machine, a   evaluation, as follows:
 single bobbin falls down and is not correctly   Type 1: 99% white viscose 1% black viscose
 identified afterwards.  Type 2: 98% white viscose 2% black viscose

 Now, a new software feature called Shade   As seen in the picture, there was virtually no
 Variation (SV) – introduced with the USTER®   difference to be seen in the packages. However,
 QUANTUM 3 Anniversary Edition – aims to help   at the next manufacturing stage, as the yarns
 customers prevent expensive fabric claims   were compressed in the knitting process, the
 arising from mixed-up color shades. In many   slightest color shade deviation would result in a
 mills, especially those using stand-alone winders,   dominant but uncontrolled barré effect, easily
 the risk of operator error is high. It might be that   affecting 4 to 5 kilograms of knitted fabric.
 light conditions in the mill make it difficult to see
 color differences properly, or an operator is not   For the shade variation feature, the USTER®
 aware of the serious negative impact that a single   QUANTUM 3 yarn clearer uses two separate
 bobbin of a different color can have. In short,   clearing channels focusing on color deviations. In
 even a single ‘wrong’ bobbin can cause   the trial, the start-up channel detected mixed-up
 hundreds of dollars of damage in customer   bobbins after measuring just two meters of the
 quality claims.  yarn, and immediately ejected the defective                           Yarns of two different color shades


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