The present invention relates to an apparatus for producing and winding synthetic multifilament yarns.
Apparatus of this type for producing and winding a plurality of synthetic multifilament yarns, which comprise a spin unit with a plurality of spinnerets, a treatment unit, and a takeup unit with a plurality of winding positions, are known in general. In these apparatus, a melt producer distributes in the spin unit a polymer melt to a plurality of spinnerets. In each of the spinnerets, the polymer melt is extruded under pressure to strandlike filament bundles, which are combined to a yarn after cooling. Thereafter, the yarns jointly advance through a treatment unit to receive defined physical properties. After the treatment, the yarns are individually wound to packages.
Depending on the construction of the individual devices, the yarns advance inside the apparatus in differently spaced relationships. For example, EP 0 845 550 and corresponding U.S. Pat. No. 5,928,579 disclose that the spacing between yarns differs respectively in the spinning, treating, and winding steps. Thus, after the treatment step, it is necessary to spread the yarns for winding to a larger spacing between yarns, so that the advancing conditions of the yarns from a guide roll upstream of the takeup unit differ from yarn to yarn. In particular in cases, where the yarns are imparted a crimp in the treatment unit, a spreading and therewith connected friction values by yarn guides and the different downstream advancing conditions may directly have a negative effect on the quality data of the crimped yarns.
To distribute the yarns after their treatment as much as possible under identical deflection conditions to the individual winding position of the takeup unit, there are only devices known in the art, wherein the guide roll upstream of the takeup unit is dimensioned in its length such that the yarns are able to advance after their treatment substantially parallel to the takeup device. Devices of this type, as are disclosed, for example, in WO 96/09425 and corresponding U.S. Pat. No. 5,794,868, but they have the disadvantage that the units for treating and guiding the yarns must be designed for a spacing between yarns that is predefined by the winding positions. With that, long-projecting as well as very wide treatment units are needed, which result in particular in an inferior operability.
It is therefore an object of the invention to provide an apparatus of the described type for producing and winding synthetic multifilament yarns, which permits advancing the yarns for the most part under identical conditions from a small spacing between yarns necessitated by a treatment unit to a larger spacing between yarns necessitated by a takeup unit.
USPTO Backgrounds
USPTO Backgrounds