In the past, we used umbrellas when it rained, but it was still easy to get wet. Then the witty people began to develop the road of waterproof series products. Up to now, waterproof materials have been gradually used in clothing, umbrellas, watches, luggage and other industries to make products. 
The Zipper is a convenient mechanism for clothing, shoes, luggage and other products. If all the parts have waterproof skills, but the zipper does not, it will fall short, so the zipper also admits defeat and adds new skills to himself. 
Waterproof Zipper is a kind of Nylon Zipper or Plastic Zipper with special coating. The special treatment of waterproof zipper includes: sticking PVC, sticking TPU film, soaking in waterproof agent, coating waterproof zipper. Among them, the waterproof zipper with TPU film is currently the most conventional and cost-effective waterproof zipper product. 
TPU waterproof zipper was born in the 1990s. Because TPU waterproof zipper is resistant to cold -40°C, high temperature of 100°C, waterproof, breathable, low temperature resistance and good softness, it has been well received by domestic and foreign customers. The properties of the coated waterproof zipper are: no falling off, no embrittlement, low temperature resistance -70°C, environmental protection, softness, and good water resistance. Waterproof Zippers are widely used in winter clothing, ski clothing, down jackets, sailing clothing, tents, car and boat covers, fishing clothing and other waterproof related products. 
However, it should be noted that since the back of the waterproof zipper is a nylon zipper or a plastic zipper, there are gaps between the elements of the zipper. When the zipper is completely immersed in water, the water will still pass through the elements. Therefore, the waterproof zipper can only be splash-proof, and cannot be immersed in water without leaking, so conventional waterproof Zippers cannot be used on wetsuits or raincoats.
So it's actually better to call this zipper as "water resistant zipper" than "waterproof zipper", the surface can resist waterdrop, but cannot be totally keep the zipper dry when soak it into water.
