A thermal plastic elastomer injection mold comprises: a mold base, formed with a platform having a top surface thereof formed with an arc-shaped surface adhered with a pair of support-tapes of a slide fastener and formed with an elongated arc-shaped ridge having a wedge-shaped tip thereby being able to be stably moved into a gap between the pair of support-tapes and a surface of the arc-shaped ridge is formed with a thermal plastic elastomer injection port connected to at least one extruder; and a thermal plastic elastomer, extruded out from the at least one extruder and passing the thermal plastic elastomer injection port so as to be injected into the gap and slits inside two rows of coupling elements disposed at inner edges of the pair of support-tapes, wherein the slide fastener is formed with a water impervious structure after the thermal plastic elastomer inside the gap is cut.

A thermal plastic elastomer injection mold comprises: a mold base, formed with a platform having a top surface thereof formed with an arc-shaped surface adhered with a pair of support-tapes of a slide fastener and formed with an elongated arc-shaped ridge having a wedge-shaped tip thereby being able to be stably moved into a gap between the pair of support-tapes and a surface of the arc-shaped ridge is formed with a thermal plastic elastomer injection port connected to at least one extruder; and a thermal plastic elastomer, extruded out from the at least one extruder and passing the thermal plastic elastomer injection port so as to be injected into the gap and slits inside two rows of coupling elements disposed at inner edges of the pair of support-tapes, wherein the slide fastener is formed with a water impervious structure after the thermal plastic elastomer inside the gap is cut.