Zip fastener
A zip includes: a pair of stringer tapes, each of which supports a row of teeth; the teeth on the two tapes being mutually opposing and capable of interdigitation thereby to fasten one stringer tape to another; a slider, adapted to move along and whose motion is guided by the rows of teeth, the slider being adapted to cause interdigitation of the teeth as a result of motion along the teeth in a first direction, and to disconnect the teeth by motion along the teeth in a second direction; wherein the first and second stringer tapes are formed of a matrix of threads interspersed with a waterproof material.
1. A zip fastener for use in conjunction with a material having a native characteristic being water-resistance or fire retardancy, the zip fastener comprising:
a pair of stringer tapes, each of which supports a row of teeth;
the teeth on each tape being mutually opposing and capable of interdigitation thereby to fasten one tape to another;
a slider, adapted to move along the rows of teeth and whose motion is guided by the teeth, the slider being adapted to cause interdigitation of the teeth as a result of motion along the teeth in a first direction, and to cause extradigitation of the teeth by motion along the teeth in a second direction;
wherein the first and second stringer tapes are formed of a matrix comprising warp and weft woven threads,
wherein the warp and weft woven threads are each formed of a combination yarn comprising at least two plies, one ply comprising filaments having the native characteristic of the material.
2. A zip according to claim 1 wherein the matrix is formed by weaving at least one combination yarn comprising a combination of native material which is fusible above a predetermined temperature (‘thermofusible material’) and material which is not fusible at the predetermined temperature (‘standard material’) and applying heat to the stringer tape above the predetermined temperature thereby to melt the thermofusible material.
3. A zip according to claim 1 wherein the matrix comprises a first region in which all warp yarns are combination yarns including native material and a second region in which warp yarns are made of filaments which include no native material.
4. A zip according to claim 3 wherein the warp yarns extend substantially parallel to the rows of teeth.
5. A zip according to claim 4 wherein the second region is located on the opposing side of the respective stringer tapes from the teeth.
6. A zip according to claim 1 wherein the zip teeth are provided by a pair of continuous elements coiled around the respective edges of the stringer tapes.
7. A zip according to claim 1 wherein the native material is waterproof material, provided by silicone.
8. A zip according to claim 1 wherein the native material is fire-retardant material.
9. A method of manufacturing a zip comprising the steps of:
creating a pair of stringer tapes by weaving a weft yarn being a combination yarn comprising a ply of thermofusible material with at least one warp yarn being a combination yarn comprising a ply of thermofusible material;
attaching a row of zip teeth to an edge of each stringer tape;
attaching a zip slider to the stringer tapes such that the zip teeth of the stringer tapes oppose each other and the slider moves along the zip teeth to fasten and unfasten the zip; and
applying heat to the stringer tapes thereby to melt the thermofusible filaments.
10. A method according to claim 9 wherein the individual yarns comprise a core yarn and a plurality of peripheral yarns wrapped around the core yarn, and wherein at least the core yarn comprises a core of standard material filaments in a sheath of native material.
11. A method according to claim 10 wherein the native material is thermofusible material.
12. A zip according to claim 1 wherein the matrix is formed of warp and weft combination yarns each having a ply comprising thermofusible filaments thereby to provide a waterproof characteristic to the stringer tapes.