Process for controlling the cross-sectional structure of mesophase pitch derived fibers

In the process of producing a mesophase pitch fiber including the spinning of mesophase pitch into a fiber using a spinnerette by passing the mesophase pitch through a spinnerette channel defined between the inside and outside surfaces of the spinnerette, the improvement comprises positioning a porous body in the spinnerette channel.

In the process of producing carbon fiber from mesophase pitch, including the steps of spinning a pitch fiber from the mesophase pitch by passing the mesophase pitch through a spinnerette channel defined between inside and outside surfaces of a spinnerette, thermosetting the pitch fiber, and thereafter, carbonizing the pitch fiber to produce the carbon fiber, the improvement comprises maintaining a roughened interior surface of said spinnerette channel in the vicinity of the outer surface of said spinnerette.

In the process of producing a continuous mesophase pitch fiber including the spinning of mesophase pitch into a fiber having a diameter of less than about 60 microns using a spinnerette by passing the mesophase pitch through a spinnerette channel defined between the inside and outside surfaces of the spinnerette, the improvement comprises maintaining a roughened interior surface of said spinnerette channel in the vicinity of the outer surface of said spinnerette.