Edward Doherty

US Patent:

52982068, Mar 29, 1994

Filed:

Dec 3, 1992

Appl. No.:

7/984829

Inventors:

Robert D. Milliken - Columbia MD
David R. Barnes - Columbia MD
Amy L. Foley - Natick MA
Karen E. Dunleavy - Billerica MA
Edward J. Doherty - Mansfield MA

Assignee:

W. R. Grace & Co.-Conn. - New York NY

International Classification:

B29C 4792
D01D 524

US Classification:

264 407

Abstract:

An automated system for casting hollow fiber membranes into a variety of prescribed shapes, including spiral, linear, circular and rectangular. The system also has the capability to change the configuration during casting, which increases productivity. A co-extrusion die is rotated over a stationary coagulation bath A computer is used to control the motion of the die to make a membrane with the desired shape The nozzle is oriented in a manner that will compensate for distortions that occur in wall thickness in the area of a bend. In addition, the nozzle's annulus is offset to make the leading portion of the annulus slightly thicker and the trailing portion thinner at the point where the fluids exit the nozzle, which results in a uniformly symmetric wall thickness. A system embodying the invention includes X, Y and. theta. -directional servomotors 1A-1C (FIG.