with greater than 15 solids and inherent viscosities above 1 6 dl g have not been attempted in this work because the resins are so viscous that extrusion would be difficult however if conditions could be modified to allow extrusion using concentrations above 15 solids and inherent viscosities above 1 6 dl g solid fibers could forseeably be produced resin viscosity was measured using a brookfield viscometer at ambient temperature measurement of resin viscosities indicated that a high resin viscosity would not result in solid fibers unless the inherent viscosity and solids were also at acceptable levels however if the resin viscosity was lower than 40 poise at 24 u00b0 c with 15 resin solids and the filament diameter was near 50 microns the coagulation bath fibers always contained voids table i______________________________________70 aqueous ethylene glycol coagulation bathresin inherent fiberviscosity resin diameter solid dl g solids microns fibers______________________________________1 1 20 0 41 01 3 20 0 84 801 2 15 0 54 01 3 14 5 50 111 6 14 5 64 951 6 14 5 45 1001 6 14 5 31 1001 9 15 0 63 1002 1 1 6 9 7 47 75______________________________________ table ii______________________________________aqueous ethanol coagulation bath resin inherent fiber aqueous viscosity resin diameter solidsetoh dl g solids microns fibers______________________________________80 1 3 14 5 34 10080 1 6 14 5 55 8380 1 6 14 5 35 10070 1 3 14 5 28 7370 1 6 14 5 54 10070 1 6 14 5 33 10070 1 1 20 0 37 6060 1 3 14 5 48 0______________________________________ ethylene glycol etg ethanol etoh and aqueous solutions of either etg or etoh were investigated as coagulation media to produce solid core fiber solid coagulation bath fibers were obtained using either 70 75 aqueous.