A Study of Cotton Fiber Perimeters as Calculated from Arealolneter Values at Low and High Compression

For a group of cottons selected to show a wide range in fiber perimeter, differences in perime ter as calculated from arealometer specific surface and D, for ginned lint samples, were similar to differences in primary-wall perimeter; and the actual perimeter values differed little from those calculated from specific surface and array weight per inch. Moreover, calculated weight per inch differed little from values obtained by the array method. It was shown for a second group of cottons that, with but few exceptions, D, and consequently perimeter, etc., calculated from specific surface and D, decreased from raw stock to picker lap and then increased succes sively for card sliver, first and second drawing sliver, and roving, the greatest changes in D occurring in the conversion of card sliver to first drawing sliver and second drawing sliver to roving. These results indicate that the fiber property values calculated from A and D will be valid for ginned lint samples, but will vary with processed samples and particularly will not be valid for samples that have been subjected to considerable mechanical drafting.