This is a spinning system in which the spinning frame is fed by the drawing frame sliver and builds up directly the cones, omitting the roving frame passage and in many cases the cone winding.
The fibres composing the sliver are drawn and individually separated by an opening roller and are conveyed into a rotor which regroups them and imparts the twist to the yarn.
The rotor speed has now reached 130.000 rpm, which enables to the machines a considerable production.
The system has however a technical limit: in fact as not all fibres are positioned parallel to the yarn axis, the yarn has a lower tenacity. Moreover a certain number of fibres per cross-section is necessary, therefore it is not possible to spin counts finer than Ne 32-36. The produced yarn is of optimal quality and is used also to produce knitwear and plush fabrics, besides household textiles and denim.
The open-end spinning frame, thanks to its particular configuration (feeding through slivers, take-up on cones) has enabled a complete production automation through following units:
· automatic can-changing
· piecing of the fed sliver
· piecing of the broken yarns and automatic rotor cleaning
· change of the full cones and feed of the tubes
· production of metered cones
· control of yarn regularity
· centralized control of all machine functions.
The production data of the spinning machine can be displayed on a video terminal or printed for each spinning position or for each section or each shift. The possibility of producing low twist yarns and of spinning successfully polyester, acrylic and viscose fibres, both pure and blended, make this machines highly flexible.
