A monofilament having, in cross section, a first width and a second width being orthogonal to the first width and being greater than the first width is helically wound about the circumference surface of the mandrel. Each helical unit included in the configured helix of the monofilament includes a pair of legs, a first coupling portion coupled between said pair of legs, and a second coupling portion coupled between one leg of said pair of legs and the other leg of a pair of legs in an adjacent helical unit. The second width of said first coupling portion is oriented along the axial direction of the mandrel. The first coupling portion in each helical unit in the helix is pressed such that the second width of the first coupling portion is widened in its width direction, thereby forming an engagement head.

A molded-teeth slide fastener tape for use in a slide fastener assembly includes a woven portion and a plurality of resin-based teeth. The woven portion includes a cord arranged along an edge thereof and a plurality of spaced-apart perforations, disposed adjacent to the cord, which pass completely through the woven portion. Each of the plurality of resin-based teeth is integrally molded to the woven portion along the cord. Each molded tooth encompasses at least a portion of at least one of the spaced-apart perforations so that each molded tooth extends through the at least one of the spaced-apart perforations and fully around a cross-sectional shape of the cord.

A method for manufacturing a watertight zipper includes forming a waterproof tape by extruding a polymeric material in a melted state wrapping around a cloth tape, cutting a side of the waterproof tape that is covered by the thick waterproof layer to form a side surface of the thick waterproof layer as an abutting surface, forming a plurality of apertures in the waterproof tape that extends through the cloth tape and the thick waterproof layer, and forming a plurality of scoops spaced from the thin waterproof layer and corresponding to the apertures. The waterproof tape includes a thick waterproof layer and a thin waterproof layer both formed by the polymeric material. The thick waterproof layer covers an upper surface, a lower surface and an edge of the cloth tape. The thin waterproof layer connects with the thick waterproof layer. An end of each scoop extends beyond the abutting surface.

A fastener element has a central land portion and first and second bulging portions bulging from the central land portion toward the tape front surface side and the tape rear surface side in the element thickness direction. The first and second bulging portions respectively have a bulging end surface facing to the element thickness direction. The bulging end surface has a quadrilateral base end surface which is long in the element length direction and a tapered protrusion end surface protruding from the base end surface in the element width direction. Thus, it is possible to make the fastener element look like a single-sided metal element and to make a slide fastener which is formed by using the fastener elements lighter than a conventional slide fastener having single-sided metal elements.

A fastener element for a slide fastener includes: a coupling portion; and one single root portion either including, or being plastically bendable to include, a bent portion and a distal end portion which extends from the bent portion towards a side of the coupling portion which is closer to the fastener tape. Each face of the coupling portion includes an engaging protrusion protruding in a lengthwise direction, and an engaging recess recessed in a lengthwise direction with respect to the face, and is configured for receiving an engaging protrusion of a fastener element on the opposite stringer in a closed condition of the slide fastener.

There is provided a slide fastener. A pair of fastener element rows are respectively sewn to opposing tape side edge portions of a pair of fastener tapes with sewing threads. Each of the fastener element rows has a plurality of fastener elements. A slider is configured to engage and disengage the pair of fastener element rows. The pair of fastener tapes and the pair of fastener element rows are colored in different colors. The slide fastener is used such that the fastener element rows are at a back side. A width dimension of a gap between the pair of fastener tapes is set to be 10 to 25% of a width dimension of the pair of fastener element rows that are engaged with each other. The color of the fastener element rows is visible through the gap from a front side of the slide fastener.

There is provided a slide fastener. A pair of fastener element rows are respectively sewn to opposing tape side edge portions of a pair of fastener tapes with sewing threads. Each of the fastener element rows has a plurality of fastener elements. A slider is configured to engage and disengage the pair of fastener element rows. The pair of fastener tapes and the pair of fastener element rows are colored in different colors. The slide fastener is used such that the fastener element rows are at a back side. A width dimension of a gap between the pair of fastener tapes is set to be 10 to 25% of a width dimension of the pair of fastener element rows that are engaged with each other. The color of the fastener element rows is visible through the gap from a front side of the slide fastener.

A monofilament having, in cross section, a first width and a second width being orthogonal to the first width and being greater than the first width is helically wound about the circumference surface of the mandrel. Each helical unit included in the configured helix of the monofilament includes a pair of legs, a first coupling portion coupled between said pair of legs, and a second coupling portion coupled between one leg of said pair of legs and the other leg of a pair of legs in an adjacent helical unit. The second width of said first coupling portion is oriented along the axial direction of the mandrel. The first coupling portion in each helical unit in the helix is pressed such that the second width of the first coupling portion is widened in its width direction, thereby forming an engagement head.

A wide top narrow bottom type double-layer zipper that the width of the interlocked bottom interlocking coils is smaller than the width of the interlocked top interlocking coils; the top interlocking coils and the bottom interlocking coils have the same spiral pitch; the top and bottom layers of the wide top narrow bottom type double-layer zipper are vertically aligned and sewed; the diameter of the polyester coils extend spirally around the respective filler cords of the respective bottom interlocking coils monofilament is about 0.02 mm0.1 mm smaller than the diameter of the polyester coils monofilament that extend spirally around the respective filler cords of the respective top interlocking coils; the engaged tooth line of the top interlocking coils at the top cover panel of the zipper slider and the engaged tooth line of the bottom interlocking coils at the bottom cover panel of the zipper slider exhibit a non-superimposed relationship.

A mechanism and method for easily replacing a zipper of a zippered hardside luggage, wherein one side of a zipper is fixed to an upper case body by an upper zipper fastener, and the other side of the zipper is fixed to a lower case body by a lower zipper fastener; the upper zipper fastener and the lower zipper fastener have a respective notch; a removable notch fastener is arranged at the joint between the upper case body and the lower case body at the notch; and the replacement method comprises: firstly removing the notch fastener, pulling out the old zipper from the notches of the upper zipper fastener and the lower zipper fastener, then passing a new zipper through the notches of the upper zipper fastener and the lower zipper fastener, and finally mounting the notch fastener.