A melt spinning apparatus including a spinpack with a die tip block having a
recess
with a converging portion, such as an angled trough, which terminates in a row
of filament discharge outlets. The recess selectively receives a configuration
insert, such as a side-by-side insert or a sheath-core insert, that separates the
converging portion of the recess into two sheets of liquid that combine at the
filament discharge outlets. The spinpack may be configured by inserting either
of the inserts to produce filaments having different cross sectional configurations
of two different materials. Separation of the two liquids prevents premature interaction
between the two liquid flows which minimizes instabilities between the liquid flow
interface. The minimization of these instabilities can result in less formation
of shot and improve other significant finished product properties. In addition,
each type of liquid material may be maintained at an optimum temperature for proper extrusion.