This test method for the determination of crimp frequency of manufactured staple fibers may be used for the acceptance testing of commercial shipments but caution is advised since between-laboratory precision is known to be poor. Comparative tests conducted as directed in 5.1.1 may be advisable.

If there are differences or 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 homogeneous 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 unpaired data, at a probability level chosen prior to 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.

This test method is used for quality control. It is an unsophisticated procedure which is particularly useful in detecting major differences in crimp frequency. This test method is not considered to be useful in research and development where minor differences or more complete crimp characterization, including amplitude and index, may be necessary.

Crimp in fiber affects the carding and subsequent processing of the fiber into either a yarn or a nonwoven fabric.

Staple crimp in fiber will also affect the bulk or openness of a yarn and therefore the hand and visual appearance of the finished textile product.