Standard Test Method for Length and Length Distribution of Manufactured Staple Fibers (Single-Fiber Test)

Abstract

5.1 This test method is used for research, development, quality control, product specifications, and may be used for acceptance testing of commercial shipments of textile fibers. However, caution is advised since information on between-laboratory precision is lacking. Comparative tests as directed in 5.1.1 may be advisable. 5.1.1 If there are differences of practical significance between reported test results for two laboratories (or more), comparative tests should be performed to determine if there is a statistical bias between them, using competent statistical assistance. As a minimum, test samples that are as homogenous as possible, drawn from the material from which the disparate test results were obtained, and randomly assigned in equal numbers to each laboratory for testing. The test results from the two laboratories should be compared using a statistical test for upaired data, at a probability level chosen prior to the testing series. If a bias is found, either its cause must be found and corrected, or future test results for that material must be adjusted in consideration of the known bias. 5.2 This test method provides objective measurements for determining the average fiber length and length distribution in a sample of fiber. 5.3 The staple length diagram of a fiber sample can be used to determine the relative number of fibers above and below a specified length. If a fiber is too long, it will not process well in spinning, and if there is a preponderance of short fibers, the yarn might have lower than normal breaking strength.