Mixed-Stream Spinning of Bicomponent Fibers1

Studies of the flow properties of merged spinning solutions have led to new methods for spinning bicomponent acrylic fibers. The underlying principle is that two or more spinning solutions can be merged into a common-flow stream without any significant mixing between component streams. With proper control, the technique produces a flow stream with a predetermined arrangement of the component streams. The arrange ment of component streams can be very regular or seemingly random. When a mixed-component stream is spun from a spinnerette, a bicomponent fiber is produced. The distribution of components between and along filaments is determined by the arrangement of components in the common stream and the arrangement of holes on the spinnerette. Readily controllable variations in the mixed-stream patterning and spinnerette-hole arrangement are sufficient to permit production of a whole family of bicomponent fibers, ranging from "true" conjugate (similar to those produced with conventional conjugate spinnerettes) to fibers with a truly random distribution of components.