抄録
Unexplained phenomena of spinning and drawing properties of acrylic fiber by wet spinning can be explained by analyzing freely extruded velocity Vf regarded as a principal factor under the consideration of Barus effect of spinning solution.
(1) Actual draft V1/Vf called filament attenuation in the coagulation bath corresponds to the orientation of coagulated undrawn filament.
Vf is represented by a function of flow rate per hole Q and radius of spinnerette R.
(2) Drawing property is closely related to V1/Vf which corresponds to orientation of undrawn filament, and the lower V1/Vf results in the higher maximum draw ratio V2m/V1, which can also be seen as a function of Q, R and take-up speed of coagulated filament V1
(3) Speeding up of spinning results in decline of drawing property due to the fall of V1/Vf caused by increased shear rate of dope solution in the spinnerette.
As the result of speeding-up, tension against filament in the coagulation bath increased slightly but little in drawing bath.
(4) The difference of drawing property between sample A prepared in conventional way and sample B by anti-pilling condition is not brought by that of V1/Vf, but by those of the degree of contribution of V1/Vf to it and of molecular mobility affected by polymer composition.
