Process of making core-sheath filament yarns

A process for producing a core-sheath filament yarn, comprising:

• feeding core component polymer streams through first die channels in a first spinneret plate toward corresponding second die channels in a second spinneret plate, the core component polymer streams passing through spaces that separate the corresponding first and second die channels;
• feeding sheath component polymer streams through ring channels in the second spinneret plate and into contact with the core component polymer streams at the spaces that separate the corresponding first and second die channels, while subjecting the sheath component polymer streams to a flow resistance in the ring channels at locations adjacent to and surrounding the spaces that separate the corresponding first and second die channels, thereby enveloping the core component polymer streams with the sheath component polymer streams to form core-sheath filaments;
• and
• drawing and winding up the core-sheath filaments to form a core-sheath filament yarn having a proportion of core-sheath filaments P having a substantially identical sheath content S, wherein out of 100% of the core-sheath filaments, P, in % having sheath content within a range of (S.+-.0.1 S)%, is a value defined by an area of FIG. 1 bounded by and including curve DE, line EF and line DF, wherein curve DE is represented by the formula P=30+(0.1 S).sup.8 %.