Generally defined as ipx8 waterproof zipper, it is called airtight zipper. There are three kinds of airtight zippers: Nylon airtight, injection airtight and metal airtight. The inner teeth of the two tapes are meshed by an independent pull head of the air tight zipper, and the elastic tape is compressed by the outer teeth to form a complete air tight state. On the basis of maintaining the softness and operability of the traditional waterproof zipper, the external liquid, air, gas, water vapor, dust and light are isolated.