Q: How should zippers be cared for during washing?
Close the zipper before washing. An open chain exposes individual teeth to agitation, snagging and distortion, and a closed chain distributes the mechanical action along the tape. Turn the garment inside out, use a laundry bag for small items, and keep the wash temperature at or below about 40 degrees Celsius unless the care label states otherwise.
Use a mild liquid detergent and avoid chlorine bleach, which attacks metal plating and degrades coatings. Residue is a common cause of stiffness, so choose a rinse cycle with enough water and avoid overloading the drum. Fabric softener is best kept away from zipper tape, because it can leave a film that attracts lint and reduces slider glide.
After washing, open the zipper slightly and dry the garment in a way that lets air reach the chain. For metal chains, wipe the teeth dry if the garment will be stored damp. Prompt drying matters more than any lubricant: prolonged moisture against the tape is what turns a small amount of residual detergent into corrosion or a musty odor.