Investigating the spinnability in the dry-jet wet spinning of PAN precursor fiber

The spinnability of a spinning solution using DMSO as the solvent was investigated for dry-jet wet spinning of PAN precursor fiber. Among many variables responsible for spinnability, the coagulating conditions, the air gap length, the nonsolvent content in spinning solution, and the spinning temperature have been viewed as the key factors, and they were investigated in this study. It was found however, unlike in the wet spinning, the spinnability in dry-jet wet spinning process was barely influenced by the coagulating conditions, likely attributable to the existence of the air gap. However, the spinnability worsened when the air gap was longer than 30 mm. The quality of the spinning solution deteriorated with the increasing water content in it. The spinnability improved when the spinning temperature was maintained between 60 and 72 degrees C and turned down once the temperature was over 72 degrees C. The experimental results indicated that all the factors should be comprehensively considered to ensure good spinnability in dry-jet wet spinning process. (C) 2008 Wiley Periodicals, Inc.