Nylon spiral versus molded resin zippers: which should I choose?

Q: Nylon spiral versus molded resin zippers: which should I choose?

Nylon spiral, also called coil, is a continuous monofilament wound into teeth and stitched to the tape. It is light, thin, flexible and inexpensive, and it follows curves and corners without puckering, which makes it the default for dresses, linings, sportswear and soft bags. Because the coil can be dyed with the tape, color matching is straightforward.

Molded resin teeth are injected directly onto the tape from acetal resin. The result is stiffer and wider, with a more substantial look, better abrasion resistance and a slider that is easier to grab. It suits outerwear, backpacks, luggage and childrenswear where a chunky, colorful chain is acceptable. Resin also tolerates repeated washing without the plating loss that affects metal.

Choose coil when the seam is curved, the fabric is light, or the zipper should disappear. Choose molded resin when the zipper is a visible design element, the item is abused, or the opening needs a firm edge. Metal remains the choice when perceived quality and maximum pull strength dominate. Cost, repairability and recycling also differ, so confirm the full specification before switching materials mid-program.