Die swell behavior of cellulose diacetate spinning dope

In order to study the die swell behavior of cellulose diacetate spinning dopes at the exit of a regular triangle spinneret orifice,a laser outside diameter measuring instrument was used to investigate the die swell ratio of spinning dopes of different mass concentrations,temperatures and flowing rates and spinneret orifices of different length / diameter ratios under various shear rates. The results demonstrated that when shear rate was kept constant,with increasing of mass concentrations or flowing rates of CDA spinning dopes,the die swell ratios gradually increased,but they were in a reduction trend while increasing temperatures of dopes or the length / diameter ratios of spinneret orifices. As shear rate was increased,the die swell ratio of spinning dopes of different mass concentrations,temperatures and flowing rates and spinneret orifices of different length / diameter ratios were increased as well, with more significant increase. The research conclusion provides a basis for the further analysis on the process for spinning CDA fibers or tows by regular triangular spinneret orifices.