Dry spinning is used to form polymeric
fibers from solution. The polymer is dissolved in a volatile solvent and
the solution is pumped through a spinneret (die) with
numerous holes (one to thousands).
As the fibers exit the spinneret, air is used to evaporate the solvent so that
the fibers solidify and can be collected on a take-up
wheel. Stretching of the fibers provides for orientation of the polymer
chains along the
fiber axis. Cellulose acetate (acetone solvent) is an example of a
polymer which is dry spun commercially in large volumes. Due to safety
and environmental concerns associated with solvent handling this technique
is used only for polymers which cannot be melt spun.
An excellent general reference on fiber spinning is:
A. Ziabicki, Fundamentals of Fiber Formation,
Wiley, New York (1976). ISBN 0471982202.
A more detailed study of dry spinning is :
Y. Ohzawa, Y. Nagano, and T. Matsuo, J. Appl. Polym. Sci., 13, pp. 257-283 (1969).