Tensile Analysis
The evaluation of yarn strength through the rupture of a wound skein of specified length provides a collective measure of yarn count and break load. Utilizing lea skein testing allows spinning mills to determine the count-strength product of spun yarns under standard conditions. This method evaluates the combined performance of multiple strands of yarn simultaneously, giving a robust indication of how the yarn will perform under the high tensile stresses of warp preparation.
Mechanical Protocol
A continuous yarn is wound eighty times around a reel with a circumference of one and a half yards to form a skein of one hundred and twenty yards. In lea skein testing, this loop is placed over two rounded fixtures of a tensile tester which are then driven apart until the skein ruptures. The peak force recorded represents the skein breaking strength.
Quality Index
Calculated quality indices average out the effect of isolated thin spots that would cause premature failure in single-strand tests. While single-strand testing provides detailed variance data, lea skein testing gives a rapid and reliable average that correlates well with weaving performance. This measurement is widely used for cotton yarn quality control.
Operational Utility
Spinners use these values to make rapid adjustments to the draft and twist levels on the spinning floor. High skein strength values indicate a well-blended and properly spun yarn lot. This test is a standard for commercial yarn shipments.
