รThe visual effect of increasing laser labeling exposure time on
tangerine peel is shown in Fig. 2. At the lowest possible exposure
time of 30 µs, the label was faint and hardly visible, whereas at
the highest exposure times, the etch markings merged into solid
lines. Calculations of laser etched surface area were done using
image processing software. In general, the area covered by the
etched markings increased with increase in exposure time
The rate of peel surface area disruption declined at higher
exposure times as etch markings began to merge. Etched markings
created with 45-µs exposure time were selected as the best on
the basis of visual appearance and area covered. This exposure
time (45 µs) creates less surface disruption while generating a
readable code. However, from Figs. 2 and 3, higher exposure
times create darker labels without significantly increasing peel
disruption.