The tensile strength of wool during pre-spinning processing is examined in
this paper. Both single fiber breaking load and fiber bundle strength are s
tudied. The results confirm that carding causes more fiber damage or streng
th loss than other processes examined. The breaking load of fibers in combe
d sliver may be significantly higher than that in carded sliver, because co
mbing 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 cur
ves. Compared with the tensile curve of the ideal fiber bundle, the tensile
curve of an actual wool bundle shows a relatively higher elongation and lo
wer 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.