Double-Layered Watertight Zipper

A double-layered watertight zipper comprising first and second stringer tapes that can be engaged with each other, wherein each of the first and second stringer tapes comprises:

• a tape;
• a first leakproof layer arranged on an outer face of the stringer tape, wherein the first leakproof layer and the tape construct a waterproof tape, wherein the first leakproof layer comprises an inner face forming a first abutting face;
• a plurality of scoops arranged on the waterproof tape in intervals side by side adjacent to an inner lateral side of the waterproof tape;
• and
• a second leakproof layer arranged on the plurality of scoops and connected to the first leakproof layer, wherein the second leakproof layer comprises an inner face forming a second abutting face;
• wherein, when the plurality of scoops of the first stringer tape is engaged with the plurality of scoops of the second stringer tape, the first abutting face of the first stringer tape is in abutment with the first abutting face of the second stringer tape, and the second abutting face of the first stringer tape is in abutment with the second abutting face of the second stringer tape.