the slider may catch on thread or cloth when opened or closed.
attempting to free the slider by force will only worsen the problem.
pull the slider back, removing the trapped thread or cloth.
when the slider bites deeply into the cloth, do not force back but work back gently.
when sewing zippers on garments, take care to avoid the possibility of the zipper getting caught.
a zipper should be closed and the slider fixed before cleaning.
left open, the tip of the slider may damage the fabric or the tape may become stretched or may shrink. strong alkaline detergents or chlorine oil or stains dissolve paraffin or oily film and must be used with care. if a zipper does not work smoothly after cleaning, apply paraffin or the lubricating spray, and work the slider up and down several time until it works smoothly.