A Study of Wool's Tensile Strength in Early Stage Processing

The tensile strength of wool during pre-spinning processing is examined in this paper. Both single fiber breaking load and fiber bundle strength are studied. The results confirm that carding causes more fiber damage or strength loss than other processes examined. The breaking load of fibers in combed sliver may be significantly higher than that in carded sliver, because combing breaks weak fibers damaged in carding and increases the average fiber diameter in combed sliver by removing some fine fibers. An attempt is made to generate an ideal bundle strength profile from single fiber tensile curves. Compared with the tensile curve of the ideal fiber bundle, the tensile curve of an actual wool bundle shows a relatively higher elongation and lower tenacity, probably due to the between-fiber interactions and relatively poorer fiber orientation in the actual wool bundle. A method of minimizing fiber interaction during bundle strength testing is proposed.