A jacket zipper operates smoothly at first. The slider moves up and down without resistance, and the metal teeth mesh together completely to hold the two sides of the fabric in place.
The first changes emerge as small inconsistencies in movement. The slider pauses briefly at one or two specific teeth during operation, though it continues after a moment.
Intermediate Stage
These pauses become more frequent across additional teeth. The slider requires a gentle tug to pass over the affected areas, and the motion feels less fluid overall.
Later Stage
The teeth begin to show small separations when closed. The slider tilts slightly and does not align the teeth as tightly, resulting in a looser connection between the fabric edges.
This progression—from seamless motion to repeated hesitations and partial separations—marks the zipper's step-by-step deterioration.