A Review of Image Analysis Based Methods to Evaluate Fiber Properties

This review focuses on fiber analysis methods, where the fibers are carried in
suspension. They are photographed in a flow cell and their properties are
evaluated by digital image analysis. Three fields of fiber analysis are
covered: Fiber morphology, pulp surface chemistry, and chemically
induced swelling respectively dissolving behaviour of pulp.
Four fiber morphology commercial analyzers were compared. On an
absolute level the measurement differences between the analyzers varied
from 15% to 40%, for some morphological parameters up to 70%. Still fiber length, width, and curl results are highly correlated, so relative comparison is possible.
An increasing number of publications have recently been devoted to image
analysis based evaluation of surface chemistry respectively chemically induced fiber swelling and dissolving. Considering that research effort it can
be expected, that numerous innovations in both fields commercial fiber
analyzers as well as new machine vision based fiber analysis techniques, can be
expected in the next years.