In this paper, we investigate fiber diameter and strength distribution
s in early-stage processing. We have processed two lots of merino wool
from scouring to top finishing. Fiber samples collected at each proce
ssing stage are measured for diameter on an optical fiber diameter ana
lyzer, and fiber strength is measured on a modified WIRA single fiber
strength tester. Fiber diameter conforms to a lognormal distribution,
and this conformity persists throughout early-stage processing. Single
fiber strength also conforms to a lognormal distribution in general,
but this conformity may be distorted by fiber damage in processes such
as carding. Furthermore, we have established a formula to estimate th
e coefficient of variation of single fiber strength once we know the c
oefficient of variation of the fiber diameter.