Length Redistribution
The modification of the fiber length distribution that occurs during carding, combing, and drafting is tracked as a shift in the cumulative fiber length curve. This staple length transformation is caused by the mechanical breakages of long fiber bundles and the removal of short fibers during combing. Spinning mills measure this change to understand how raw fiber runs are modified as they progress toward the spinning frame.
Drafting Effect
Mechanical forces in the carding and combing zones break the natural pectin bonds that hold the flax fibers together. This action drives the staple length transformation, converting coarse, long scutched fiber bundles into a more uniform population of shorter fibers. If the transformation is too severe, the fiber length becomes too short for high-quality wet spinning, which requires a high proportion of long line fibers.
Processing Outcome
Sliver inspection documents record the change in mean fiber length before and after each processing stage. Controlling the staple length transformation ensures that the fiber length matches the draw frame and spinning ratch settings. When the process results in a very narrow length distribution, the yarn displays high uniformity and low count variation.
Technicians take regular sliver samples to evaluate the fiber length using array methods or photoelectric testers. Spinners use this information to adjust the draft ratios and to ensure the final linen yarn meets buyer requirements for strength and appearance, avoiding the presence of thin places that weaken the woven fabric.
