Submitted to: Journal of Cotton Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 11, 2002
Publication Date: July 1, 2003
Citation: McAlister III, D.D., Foulk, J.A., Harrison, R.E. 2003. Afis length measurement of hand sorted cottons by length group. Journal of Cotton Science 7:217-223.
Interpretive Summary: The presence of short fibers in cotton causes great concern to producers, ginners and textile manufacturers because of their adverse affect on processing efficiency and end product quality. Therefore, an accurate, precise, and rapid measurement of short fiber content has long been desired by all segments of the cotton textile industry. To date, the Advanced Fiber Information System (AFIS) is the closest thing available to satisfy this need in industry. Although not listed as an ASTM test method, the AFIS is widely used and accepted as an instrument for determining short fiber content. Earlier research has suggested that breakage of fibers in the fiber individualizer section of the machine creates a bias of the length measurement toward the short end of the length scale. This research was conducted to verify what was suggested, but not proven, by earlier researchers. Hand-sorted cotton fibers of different lengths and micronaires were tested on the AFIS to determine if damage was being done. This work concluded that, in fact, damage is being done to the fibers, and it is more severe for the longer and lower micronaire fibers. Further research will be conducted to determine possible modifications to the AFIS to eliminate fiber damage.
Upland cottons of varying micronaires (3.7, 4.3 and 5.4) were sampled in order to collect hand sortings of fibers by length groups. These fibers were tested for micronaire and strength by the Fibronaire and Stelometer, respectively, and then tested on the Advanced Fiber Information System (AFIS) to determine the fiber length values of fibers ranging in length from 0.78" - 1.29". Analysis of the AFIS data indicated that even when short fibers were not present in a sample prior to testing on the AFIS, the machine reported a short fiber content measurement. In addition, frictional properties and convolutions of individual fibers were determined for each sample by the RotorRing and Favimat, respectively. These tests indicated that the highest micronaire cottons exhibited more convolutions than the lower micronaire counterparts, and, also showed that the longest fibers exhibited higher frictional properties than their shorter counterparts.