The quality comparison of open-end rotor-spun yarns produced from cotton waste in gray state and after dyeing

To demonstrate the limits of open-end rotor spinning, the outstandingly contaminated slivers were prepared from various blowroom waste mixed with virgin cotton and noils and processed to yarn. The aim was to simulate the processing of highly contaminated cotton waste to open-end rotor yarn sustainable way and analyze the impact of trash, dust, or fiber neps in slivers to yarn quality. To verify whether the dyeing of these yarn for given final use should be adjusted, yarns with high rustic appearance and yarns containing 20% residual bleached and optically brightened fibers possibly not evenly distributed are analysed before and after dyeing. The experiment proves that the processing of 98tex and 29.5tex yarns from outstandingly contaminated sliver via R37 with exchangeable trash channel is possible at acceptable quality for denim, home textile, or linen and ensures most of the demands related to user properties and durability, including uniform staining.