A TEM Study of the Causes of Failure in the Chlorine-Hercosett® Shrink-Resist Process

Abstract

Examination by transmission electron microscopy of fibers drawn from two card slivers commercially treated by the chlorine-Hercosett® process showed the Hercosett film to be continuous over each fiber. One sliver had passed the Superwash test; almost all of the cuticular scales were flattened or sloping. Most of the fibers retained no steep scales, and none retained more than 20%. Previous work indicates that the modified scales would be much softer in water than unmodified scales. The Hercosett film on these fibers was at least 0.1 μm thick everywhere. The other sliver had failed the Superwash test, half the fibers resembled those in the first sliver, but among the other half a high proportion of the scales (from 30- 70% on different fibers) remained steep (and, correspondingly, relatively hard). On half of these the film thickness was 0. 1 μm or greater; on the other half it was less than 0.05 μm either all over or on the remaining steep scale faces. The character of these differences is such as to explain the failure of the process in the case of the second sliver. The difference in the scale shape indicates that the failure resulted from non-uniformity of chlorination. The resin considerably pene trated the cuticle.