Morphological Analysis of Shrinkproof Wool Fibers by SEM Combined with Alkaline and Enzymatic Etching Techniques: Microstructural Differences of DCCA- and Kroy-Processed Fibers

Morphologies of the shrinkproof wool fibers were analyzed by scanning electron microscopy (SEM) combined with enzymatic and alkaline etchings of the cross-sectional fiber specimens. The enzymatic etching revealed the microstructural changes of the fiber components produced by after the DCCA (dichloroisocyanuric acid)- and Kroy-processes. It was suggested that the inner-fiber reactions had extended to cell membrane complex (CMC), intermacrofibril material (int-MF), and nuclear remnants (NRs), as well as to the components in their vicinity of present in the orthocortex and paracortex of the both shrinkproof wool fibers. On the other hand, the alkaline etching gave different patterns between the DCCA- and Kroy-processed fibers; in the former fibers the paracortex and orthocortex gave weak and almost disintegrated patterns, respectively, while in the latter fibers both cortexes gave weak patterns. It was therefore supported that the inner-fiber reactions are more homogeneous in the Kroy-process than in the DCCA-process although the degrees of inner-fiber reaction are almost comparable in both processes. Based on these data, the difference in laundering effect on the Kroy- and DCCA-processed fibers was discussed.