Excerpts from the report: In preceding research with Pima cottons, ginning treatments with humid air added to seed cotton preserved fiber length; however, damp cotton retained foreign matter, which adversely affected spinning performance. Consequently, additional research on ginning was needed to determine the effects of various methods of cleaning cotton. The crusher roll in the spinning plant was known to be effective in cleaning upland cotton, but no information was available on its effectiveness in cleaning Pima cottons (Gossypium barbadense), also known as American-Egyptian and extra-long-staple cottons. This study was designed to provide some information in this area.