Fastener stringer and method for recovering fastener element

Abstract

A fastener tape (3, 3') includes one or more water-soluble yarns (6). According to the dissolution of the one or more water-soluble yarns (6), the fastener tape (3, 3') can be divided into at least: a first tape part (3a) including a first side-edge section (31, 31'); and a second tape part (3b) including a second side-edge section (32, 32').

Description

Method for recovering fastener stringers and fastener elements

[0001] The present disclosure relates to a method for retrieving fastener stringers and fastener elements.

[0002] In recent years, in connection with the Sustainable Development Goals (SDGs), there has been a demand for promoting recycling in the field of slide fasteners as well. Patent Document 1 discloses a method for recycling an article in which two components are joined by a joint, in which the joint is irradiated with electromagnetic waves to reduce the mechanical properties.

[0003] Patent Document 2 discloses forming a weakened portion in a fastener tape and using this as a base point to break the fastener tape (see Figures 1 and 2 of the document). Patent Document 3 discloses connecting left and right fastener tapes with a connecting thread (soluble thread) (see Figures 2 and 4 of the document). The connecting thread eventually dissolves, and therefore the left and right fastener tapes become separated (column 2, lines 24-26 of the document). Therefore, the connecting thread does not form part of the fastener tape.

[0004] U.S. Patent No. 10,125,452 Registered Utility Model No. 3192377 Japanese Utility Model Publication No. 59-25216

[0005] One obstacle to promoting slide fastener recycling is that slide fasteners are firmly attached to the article (e.g., clothing, bag, or shoe). That is, at the stage of recycling a slide fastener, the slide fastener does not exist as a standalone unit but is attached to the article and forms part of the article. Furthermore, slide fasteners are firmly attached to the article by any method, including (but not limited to) sewing with a sewing machine, thermocompression bonding with a thermocompression bonding machine, or adhesive bonding. Ensuring the strength of the attachment of the slide fastener to the article is a priority, and therefore, it is difficult to separate the slide fastener from the article at the attachment point. In fact, the attachment of the slide fastener to the article is performed after the slide fastener is sold and is outside the control of the slide fastener manufacturer.

[0006] As is clear from the above non-limiting exemplary description, the inventors of the present application have discovered a new problem of promoting the recycling of slide fasteners based on the structure of the slide fasteners themselves.

[0007] A fastener stringer according to one aspect of the present disclosure includes a fastener tape having first and second side edges extending in a longitudinal direction of the fastener tape, and a plurality of fastener elements attached to the first side edge. The fastener tape includes one or more water-soluble threads. In response to dissolution of the one or more water-soluble threads, the fastener tape is separable into a first tape portion including the first side edge and a second tape portion including the second side edge.

[0008] A fastener stringer according to another aspect of the present disclosure includes a fastener tape having first and second side edges extending in a longitudinal direction of the fastener tape, and a plurality of fastener elements attached to the first side edge. The fastener tape includes one or more water-soluble threads. In response to dissolution of the one or more water-soluble threads, a tape portion including the first side edge with the plurality of fastener elements attached thereto is separable from the remainder of the fastener tape.

[0009] A method for recovering a plurality of fastener elements attached to a fastener tape of a fastener stringer according to another aspect of the present disclosure includes a step of exposing at least a portion of the fastener tape to hot water or high-temperature steam to dissolve one or more water-soluble threads contained in the fastener tape, and a step of separating a tape portion of the fastener tape to which a plurality of fastener elements are attached from the remainder in response to the dissolution of the one or more water-soluble threads.

[0010] The following features, or any combination thereof, may be applicable to the above or other aspects of the present disclosure.

[0011] In some embodiments, the fastener tape further comprises a plurality of water-insoluble threads, and the number of the one or more water-soluble threads is less than 1 / 2, less than 1 / 3, or less than 1 / 4 of the number of the plurality of water-insoluble threads.

[0012] In some embodiments, the one or more water-soluble yarns are soluble in hot water or high-temperature steam. The water-soluble yarns may be made of one material selected from the group consisting of water-soluble polyvinyl alcohol (PVA) synthetic fibers, alkali-soluble copolyester yarns, and alkali-soluble yarns such as polylactic acid yarns, or any combination thereof.

[0013] In some embodiments, the one or more water-soluble threads include all threads that cross a dividing line relating to the boundary between the first tape section and the second tape section.

[0014] In some embodiments, one or more water-soluble threads are locally incorporated into the ground structure of the fastener tape.

[0015] In some embodiments, the one or more water-soluble yarns comprise ground yarns of the ground structure of the fastener tape.

[0016] In some embodiments, the one or more water-soluble yarns comprise a plurality of ground yarns of the ground structure of the fastener tape.

[0017] In some embodiments, the fastener tape comprises a knitted fabric.

[0018] In some embodiments, one or more water soluble yarns are incorporated within the total width of a predetermined number of adjacent wales of the knitted fabric.

[0019] In some embodiments, the predetermined number of wales is no more than 1 / 2, or no more than 1 / 3, or no more than 1 / 4 of the total number of wales included in the knitted fabric.

[0020] In some embodiments, the one or more water-soluble yarns include N (N is a natural number greater than or equal to 2) water-soluble yarns, and each of the N water-soluble yarns extends in the course direction of the knitted fabric to connect M (M is a natural number greater than or equal to 2) wales included in the knitted fabric.

[0021] In some embodiments, the N water-soluble yarns include at least one satin yarn or weft-insertion yarn.

[0022] In some embodiments, the N water soluble yarns include at least one tricot yarn.

[0023] In some embodiments, the mathematical formula: M−N=1 is satisfied.

[0024] In some embodiments, the one or more water soluble threads do not cross a centerline for the fastener tape that extends longitudinally at a central location across the width of the fastener tape.

[0025] In some embodiments, the fastener tape comprises a woven fabric.

[0026] In some embodiments, the one or more water-soluble threads are sutures that suture the ground tissue of the first tape section and the ground tissue of the second tape section.

[0027] In some embodiments, each fastener element of the plurality of fastener elements is made of metal.

[0028] According to one aspect of the present disclosure, recycling of slide fasteners can be promoted based on the structure of the fastener tape itself.

[0029] FIG. 1 is a schematic front view of a slide fastener according to one embodiment of the present disclosure. FIG. 2 is a schematic perspective view of a fastener element. FIG. 3 is a schematic diagram showing an engaged state of left and right fastener elements. FIG. 4 is a schematic diagram showing that a fastener tape of a slide fastener can be separated into first and second tape portions. FIG. 5 is a schematic diagram showing the knitted structure of a fastener tape, showing a state in which the water-soluble yarn is not dissolved. FIG. 6 is a schematic diagram showing the knitted structure of a fastener tape, showing a state in which the water-soluble yarn has dissolved. FIG. 7 is a schematic diagram showing another knitted structure of a fastener tape. FIG. 8 is a schematic diagram showing a state in which the water-soluble yarn has dissolved in the knitted structure shown in FIG. 7. FIG. 9 is a schematic diagram showing the woven structure of a fastener tape. FIG. 10 is a schematic partial front view of a fastener stringer according to another embodiment. FIG. 11 is a schematic partial front view of a fastener stringer according to yet another embodiment. FIG. 12 is a schematic front view of a slide fastener according to yet another embodiment. FIG. 13 is a schematic diagram showing yet another knitted structure of a fastener tape. FIG. 14 is a schematic diagram showing the structure of yet another knitted fabric of the fastener tape.

[0030] Various embodiments and features will be described below with reference to the drawings. Those skilled in the art will be able to combine the embodiments and / or features without the need for excessive explanation, and will also be able to understand the synergistic effects of such combinations. Duplicate descriptions between embodiments will be omitted as a general rule. The reference drawings are primarily intended to describe the invention, and are simplified for ease of illustration. Each feature is not only effective for the fastener stringer disclosed in this application, but is understood as a universal feature that can also be applied to various other fastener stringers not disclosed in this specification.

[0031] With respect to the slide fastener 1, the movement direction of the slider 5 coincides with the front-to-rear direction. One direction perpendicular to the movement direction of the slider 5 is the left-to-right direction, which is parallel to the fastener tapes 3, 3' (or the tape surface defining the thickness thereof). Another direction perpendicular to the movement direction of the slider 5 is the up-to-down direction, which is perpendicular to the fastener tapes 3, 3' (or the tape surface defining the thickness thereof). The front-to-rear direction, left-to-right direction, and up-to-down direction may alternatively be interpreted as the longitudinal direction, width direction, and thickness direction, respectively. Directions may also be defined in other ways in light of the contents of this disclosure.

[0032] The configuration and function of the slide fastener 1 will be outlined with reference to Figure 1. As shown in Figure 1, the slide fastener 1 has a pair of left and right fastener stringers 2, 2' and a slider 5 attached to the pair of left and right fastener stringers 2, 2' so as to be movable in the front-to-rear direction. Each fastener stringer 2, 2' includes fastener tapes 3, 3' and multiple fastener elements 4, 4'. When the slider 5 moves forward, the left and right fastener elements 4, 4' are engaged with each other, resulting in engagement of the left and right fastener stringers 2, 2' (in a range rearward of the slider 5). When the slider 5 moves backward, the left and right fastener elements 4, 4' are disengaged from each other, resulting in disengagement of the left and right fastener stringers 2, 2' (in a range forward of the slider 5).

[0033] The fastener tapes 3, 3' are highly flexible strips having a predetermined width and extending in a predetermined direction. Specifically, the fastener tapes 3, 3' have first side edges 31, 31' and second side edges 32, 32' extending in the longitudinal direction (i.e., the front-to-back direction) of the fastener tapes 3, 3', and tape main bodies 33, 33' extending in the same direction (i.e., the front-to-back direction) between the first side edges 31, 31' and the second side edges 32, 32'. In some cases, the first side edges 31, 31' are first ears of the fastener tapes 3, 3' to which the fastener elements 4, 4' are attached, and the second side edges 32, 32' are second ears of the fastener tapes 3, 3' to which the fastener elements 4, 4' are not attached. The ears may have a different structure (e.g., a woven structure or a knitted structure) from the tape main body.

[0034] The fastener tapes 3, 3' include water-soluble yarns and water-insoluble yarns. Typically, water-soluble yarns are insoluble in room temperature water but soluble in hot water. Water-insoluble yarns are insoluble in both room temperature water and hot water. The hot water has a temperature equal to or higher than the dissolution temperature of the material of the water-soluble yarns (e.g., 80°C, 85°C, or 95°C or higher). The hot water may be acidic, neutral, or alkaline, but is typically neutral or weakly alkaline. Additives for promoting dissolution of the water-soluble yarns and / or other types of additives (e.g., pH adjusters) can be added to the hot water.

[0035] In some cases, the number of water-soluble threads is less than 1 / 2, 1 / 3, or 1 / 4 of the number of water-insoluble threads. Additionally or alternatively, the mass or total mass of the water-soluble threads in the fastener tapes 3, 3' is less than the total mass of the water-insoluble threads in the fastener tapes 3, 3'. In some cases, the mass or total mass of the water-soluble threads in the fastener tapes 3, 3' is 1 / 5 or less or 1 / 10 or less of the total mass of the water-insoluble threads in the fastener tapes 3, 3'. By adjusting the amount of water-insoluble threads in the fastener tapes 3, 3' in this way, it is possible to prevent the price of the slide fastener 1 from increasing while promoting recycling of the slide fastener 1.

[0036] In the recycling process, the water-soluble yarn dissolves in hot water and disappears from the fastener tapes 3, 3'. By not introducing excessive or unnecessary water-soluble yarn into the fastener tapes 3, 3', it is possible to achieve both increased recycling efficiency and avoid an increase in the cost of the slide fastener 1. Preferably, the number of water-soluble yarns contained in the fastener tapes 3, 3' is only two, three, four, or five. Note that water-soluble yarns are usually more expensive than water-insoluble yarns.

[0037] The fastener tapes 3, 3' include a knitted fabric (knitted structure) and / or a woven fabric (woven structure). The knitted fabric of the fastener tapes 3, 3' is knitted from water-soluble yarn and water-insoluble yarn (i.e., not all of the constituent yarns of the knitted fabric are water-soluble yarn). The woven fabric of the fastener tapes 3, 3' is knitted from water-soluble yarn and water-insoluble yarn (i.e., not all of the constituent yarns of the woven fabric are water-soluble yarn). Specific examples of the knitted fabric and woven fabric of the fastener tapes 3, 3' will be described later.

[0038] Water-soluble threads do not dissolve in room temperature water but do dissolve in hot water; specifically, they dissolve when immersed in hot water at a temperature equal to or higher than the dissolution temperature of the material of the water-soluble thread (e.g., 95°C). Water-soluble threads dissolve immediately or only slightly when immersed in water at a temperature lower than the dissolution temperature of the material of the water-soluble thread (e.g., room temperature water). Therefore, even if the fastener tapes 3, 3' contain water-soluble threads, the mechanical strength of the fastener tapes 3, 3' is not impaired during normal use. Specifically, even if a garment to which the slide fastener 1 is attached is washed in a washing machine, the mechanical strength of the slide fastener 1 can be maintained as long as hot water exceeding a predetermined temperature (e.g., 95°C) is not used.

[0039] Naturally, water-insoluble yarns do not dissolve in either room temperature water or hot water; more specifically, they do not dissolve even when immersed in hot water at a temperature equal to or higher than the melting temperature of the water-soluble yarn material (e.g., 95°C). If the water-insoluble yarn is a thermoplastic resin, the water-insoluble yarn melts when heated to the melting temperature of the thermoplastic resin (e.g., for polyester, the melting temperature is 200°C or higher). However, as mentioned above, the water-insoluble yarn does not dissolve or melt when immersed in hot water at a temperature equal to or higher than the melting temperature of the water-soluble yarn material (e.g., 95°C). Therefore, "water-insoluble yarn" can be said to be a yarn that does not dissolve or melt under the dissolving conditions of "water-soluble yarn." Furthermore, when immersed in hot water at a temperature equal to or higher than the melting temperature of the water-soluble yarn material (e.g., 95°C), physical, chemical, or structural changes (e.g., thermal shrinkage) may occur in the water-insoluble yarn, but this is not a problem because it is in the recycling stage. The material of the water-insoluble yarn is not limited to a thermoplastic resin, but may also be a thermosetting resin. In this specification, the maximum temperature of the hot water is assumed to be 100°C, but the use of high-temperature steam exceeding 100°C is not excluded. The high-temperature steam is set to a temperature below the temperature at which the water-insoluble yarn melts. Generally speaking, the water-soluble yarn is dissolved by exposure to hot water or high-temperature steam.

[0040] There are no particular limitations on the materials of the water-soluble and water-insoluble yarns. In some cases, the water-soluble yarn is a thermoplastic fiber with water-soluble properties. Specifically, the water-soluble yarn is made of a material selected from the group consisting of water-soluble polyvinyl alcohol (PVA) synthetic fibers, alkali-soluble copolymer polyester yarns, and alkali-soluble yarns such as polylactic acid yarns, or any combination thereof. In some cases, the water-insoluble yarn is made of a material selected from the group consisting of polyester, nylon, cotton, and rayon, or any combination thereof. Of course, the water-soluble yarn described herein can also include blended yarns of water-soluble and water-insoluble fibers. Blended yarns of water-soluble and water-insoluble fibers may be partially dissolved by immersion in hot water and may no longer be able to maintain their shape as a yarn. In some cases, the water-soluble fiber is included in a higher ratio than the water-insoluble yarn.

[0041] There are no particular limitations on the yarn properties and / or yarn structure of the water-soluble yarn and the water-insoluble yarn. In some cases, the water-soluble yarn and / or the water-insoluble yarn is a multifilament yarn formed by twisting together monofilament yarns, but this type is not intended to be limiting. The water-soluble yarn may be a yarn that loses weight by 50% by mass or more when left standing for 10 minutes in water at 95°C with a bath ratio (yarn weight:liquid weight) of 1:50. The water-soluble yarn preferably loses weight by 50% by mass or more when left standing for 10 minutes in water at 95°C with a bath ratio (yarn weight:liquid weight) of 1:50. More preferably, the water-soluble yarn loses weight by 80% by mass or more when left standing for 10 minutes in water at 95°C with a bath ratio (yarn weight:liquid weight) of 1:50.

[0042] The tensile strength of the water-soluble thread can be 3 cN / dtx or more, for example, 3 to 5 cN / dtx. When used as a suture, the water-soluble thread preferably has a high tensile strength, such as a seam tensile strength of 350 N or more, for example, 350 to 500 N. The tensile strength of the thread refers to the single yarn tensile strength (standard time) measured by the JIS method specified in JIS L1095:2010. The seam tensile strength refers to the grab method (seam horizontal method, standard time seam tensile strength) specified in JIS L1093:2011.

[0043] A plurality of fastener elements 4, 4' are attached to the first side edge portions 31, 31' of the fastener tapes 3, 3'. The fastener elements 4, 4' are typically metal elements, but are not limited thereto. They may be resin elements or elements containing at least a portion of a ceramic material. When the fastener elements 4, 4' are metal elements, separating the fastener elements 4, 4' from the fastener tapes 3, 3' enables recycling of the metal material. Furthermore, for the fastener tapes 3, 3' from which the fastener elements 4, 4' have been removed, recycling of the constituent material of the fastener tapes 3, 3' (typically, the resin material of the constituent threads) becomes possible. From the viewpoint of recycling the metal material, the constituent material (e.g., resin) of the fastener tapes 3, 3' may be ineligible for recycling (although, of course, this is not limited thereto). From the viewpoint of recycling the constituent material (e.g., resin) of the fastener tapes 3, 3', the metal material of the fastener elements 4, 4' may be ineligible for recycling (although, of course, this is not limited thereto).

[0044] FIG. 2 shows an embodiment in which the fastener elements 4, 4' are metal elements. As shown in FIG. 2, the fastener elements 4, 4' have a head 41 and a pair of legs 42, 43 connected to the head 41. The first side edge 31, 31' of the fastener tape 3, 3' is inserted between the pair of legs 42, 43, and the pair of legs 42, 43 are crimped to sandwich the first side edge 31, 31'. As a result, the attachment of the fastener elements 4, 4' to the first side edge 31, 31' is completed. A core cord (not shown) may be provided to the first side edge 31, 31'. In either case, the first side edge 31, 31' is firmly sandwiched between the pair of legs 42, 43, so that the fastener elements 4, 4' do not easily fall off the first side edge 31, 31'. The head 41 has an engaging protrusion 41a (see FIG. 1) and an engaging recess 41b, but this embodiment is not limited to this. It is also possible for the head 41 to have a pair of engaging projections projecting in opposite directions.

[0045] 3 shows a schematic diagram of the engagement state of the left and right fastener elements 4, 4'. As shown in a partial cross section in the figure, the engagement convex portion 41a of the left fastener element 4 is loosely fitted into the engagement concave portion 41b of the mating right fastener element 4'. Such engagement between the left and right fastener elements 4, 4' occurs continuously in the front-to-rear direction, thereby achieving engagement between the left and right fastener stringers 2, 2'. It is also assumed that the left and right fastener elements 4, 4' have other engagement structures and are engaged in a manner different from that shown in the figure.

[0046] In this embodiment, as shown in FIG. 4 , the fastener tape 3 can be divided into a first tape portion 3a and a second tape portion 3b at a dividing line SL. In short, the fastener tape 3 is divided into the first and second tape portions 3a, 3b as the water-soluble thread contained in the fastener tape 3 dissolves. In other words, the first tape portion 3a, including the first side edge portions 31, 31′ with multiple fastener elements 4, 4′ attached, can be separated from the remaining portions of the fastener tape 3, 3′ as the water-soluble thread dissolves. Thus, recycling of the slide fastener 1 can be promoted based on the structure of the fastener tape 3 itself. The same applies to the fastener tape 3′. Note that, depending on the manner in which the water-soluble thread is introduced in the fastener tapes 3, 3′, the dividing line SL can be formed as a wide line like a dividing band. A non-linear dividing line SL is also conceivable.

[0047] When the fastener tapes 3, 3' are immersed in hot water with the slide fastener 1 attached to the article body, the water-soluble thread dissolves, and the first tape portion 3a to which the fastener elements 4 are attached separates from the second tape portion 3b and the article body. This promotes recycling of the material (e.g., metal) of the fastener elements 4, 4'. Because the individual fastener elements 4, 4' are attached to the first tape portion 3a, there is no need to laboriously collect the fastener elements 4, 4'. The second tape portion 3b can remain attached to the article body. In this regard, the second tape portion 3b does not have the fastener elements 4, 4' attached, thereby ensuring compatibility with the total or partial recycling of the article body. For example, if both the article body and the second tape portion 3b are made of the same or similar resin material, the second tape portion 3b can be considered part of the article body and recycled while attached to the article body.

[0048] In addition, when the fastener tapes 3, 3' are separated into the first tape portion 3a and the second tape portion 3b, the water-soluble thread contained in the fastener tapes 3, 3' has already dissolved. Therefore, it is not possible to reconstruct the fastener tape 3 from only the first tape portion 3a and the second tape portion 3b. Reconstruction of the fastener tape 3 requires not only the first tape portion 3a and the second tape portion 3b but also the water-soluble thread (which has disappeared from the fastener tapes 3, 3' due to dissolution).

[0049] The first tape portion 3a includes first side edge portions 31, 31' and a portion 33a of the tape main body portion 33. The second tape portion 3b includes second side edge portions 32, 32' and a remaining portion 33b of the tape main body portion 33. In some cases, the first tape portion 3a is narrower than the second tape portion 3b. This allows the amount of non-recyclable materials (e.g., resin) to be reduced when recycling the fastener elements 4, 4'. At the same time, the amount of recyclable materials (e.g., resin) to be increased when recycling the fastener tapes 3, 3'. In this regard, it is desirable to introduce the water-soluble yarn 6 at the center position of the width of the fastener tapes 3, 3' so as not to cross the center line of the fastener tapes 3, 3' extending in a predetermined direction.

[0050] In some cases, the division line SL is located closer to the first side edge 31, 31' than the center line TC of the fastener tape 3, 3', which extends in a predetermined direction at the center position of the width of the fastener tape 3, 3'. That is, the division line SL can be set at any position between the center line TC and the first side edge 31, 31' in the width direction of the fastener tape 3, 3'. Similarly, the division line SL can be set at any position between the center line TC and the fastener element 4, 4' in the width direction of the fastener tape 3, 3'. It should be noted that the number of division lines is not limited to one. Two division lines can also be set for one fastener tape 3, 3'.

[0051] The fastener tapes 3, 3' are sewn to the article body along a sewing line L9. The sewing line L9 is closer to the second side edges 32, 32' than the dividing line SL. In the case shown in Figure 4, the sewing line L9 is between the dividing line SL and the center line TC, which reduces the exposed area of ​​the fastener tapes 3, 3' when the slide fastener 1 is attached to the article body, but this is not necessarily limited to this. A sewing mode in which the sewing line L9 is closer to the second side edges 32, 32' than the center line TC is also conceivable.

[0052] Although it is possible to divide the fastener tapes 3, 3' into the first and second tape portions 3a, 3b using a single water-soluble thread, it is preferable to include multiple (e.g., two, three, four, or five) water-soluble threads in the fastener tapes 3, 3' in order to ensure the strength of the fastener tapes 3, 3' or from another perspective. By introducing multiple water-soluble threads, the connection between the first and second tape portions 3a, 3b (which separate as the water-soluble threads dissolve) can be strengthened. This also makes it possible to deal with unexpected situations in which the water-soluble threads of the fastener tapes 3, 3' are physically cut by contact with a sharp blade when the slide fastener 1 is in use.

[0053] It is preferable to introduce water-soluble yarn into the fastener tape 3, 3' as the ground yarn of the ground structure (e.g., knitted or woven fabric) of the fastener tape 3, 3'. This allows the water-soluble yarn to be embedded in the other water-insoluble ground yarns of the ground structure, making the appearance and texture of the fastener tape 3, 3' equivalent to those of a normal fastener tape 3, 3'. When the ground structure of the fastener tape 3, 3' contains multiple types of ground yarn, the ground yarn is not limited to being selected from one type of ground yarn, but can also be selected from multiple types of ground yarn and be water-soluble yarn. Preferably, the water-soluble yarn is introduced locally into the ground structure of the fastener tape 3, 3'. These features will be understood more specifically from the explanation below.

[0054] Fig. 5 shows a knitted structure in which the fastener tapes 3, 3' are knitted fabrics and some ground yarns of the knitted fabrics of the fastener tapes 3, 3' are water-soluble yarns 6 (shown by dotted lines). Fig. 6 shows the knitted structure after the water-soluble yarns 6 have dissolved. In Fig. 5, the first and second tape portions 3a, 3b are connected by the water-soluble yarns 6, but in Fig. 6, the water-soluble yarns 6 have dissolved in hot water and disappeared, so the first and second tape portions 3a, 3b are no longer connected and can be separated.

[0055] The fastener tape 3, 3' includes a plurality of wales W1 to W16 and a plurality of connecting yarns connecting the wales W1 to W16. The wales W1 to W16 are formed by chain stitch yarn 71. The connecting yarns include satin yarn 72 and weft insertion yarn 73. The chain stitch yarn 71 forming the wales W1 to W16 is connected in the course direction by the satin yarn 72 and weft insertion yarn 73. As a result, a warp knit having a two-dimensional spread is constructed. Other knitted fabrics can also be used. The satin yarn 72 extends in the wale direction while oscillating at a predetermined width, and forms loops at the reversal points in the course direction to intertwine with the wales (e.g., chain stitch yarn). The weft insertion yarn 73 extends in the wale direction while oscillating at a predetermined width without forming loops. All yarns other than the water-soluble yarn 6 are water-insoluble yarns 7.

[0056] In the non-limiting example shown in Figure 5, three of the twelve satin yarns 72 are water-soluble yarns 61, 62, and 63 that dissolve in hot water. The twelve satin yarns are configured as ground yarns for the ground structure to meet the strength required for the fastener tapes 3, 3'. Of the multiple types of ground yarns that make up the ground structure, namely, the chain stitch yarn 71, the satin yarn 72, and the weft-insertion yarn 73, it is not necessary to selectively use the water-soluble yarn 6 only for the satin yarn. For example, some additional chain stitch yarns can be used as the water-soluble yarn 6 (the chain stitch yarn 71 in wales W5 and W6 can also be used as the water-soluble yarn). In a structure that does not contain satin yarn, some weft-insertion yarns can be used as the water-soluble yarn instead of the satin yarn.

[0057] In particular, all yarns crossing the dividing line SL may be water-soluble yarns 6. With reference to Figure 5, the dividing line SL is set between wales W5 and W6, and therefore all connecting yarns (satin yarns in the illustrated example) extending in the course direction across wales W5 and W6 are water-soluble yarns. When the dividing line SL is set on a wale, the constituent yarns of that wale may also be water-soluble yarns, but this is not necessarily the case.

[0058] 5 and 6, the water-soluble yarn 6 is introduced locally into the knitted fabric, in short, within the total width of a predetermined number of adjacent wales. As a result, the water-soluble yarn 6 is embedded in a group of water-insoluble yarns 7, and the properties of the fastener tapes 3, 3' can be determined solely based on the properties of the water-insoluble yarns 7. The predetermined number mentioned here can be 1 / 2 or less, 1 / 3 or less, or 1 / 4 or less of the total number of wales included in the knitted fabric.

[0059] In the example shown in Figure 5, the water-soluble yarn 6 is introduced within a total of six wales, W3 to W8, between the imaginary line L1 and the center line TC. Specifically, the water-soluble yarn 6 includes a water-soluble satin yarn 61 that oscillates and extends in the wale direction across the total width of wales W3 to W6, a water-soluble satin yarn 62 that oscillates and extends in the wale direction across the total width of wales W4 to W7, and a water-soluble satin yarn 63 that oscillates and extends in the wale direction across the total width of wales W5 to W8. The total number of these water-soluble yarns 6 (=3) is one less than the number of wales (=4) corresponding to the amplitude width of each water-soluble yarn 6. In general terms, when yarns that oscillate and extend in the wale direction across a given width are adjacent in adjacent wales, M-N=1 is satisfied, where M is a natural number of 2 or greater indicating the number of wales, and N is a natural number of 2 or greater indicating the total number of water-soluble yarns 6. In the case shown in Figure 5, there are a total of 18 threads extending in the wale direction, of which three are water-soluble threads 6, and the number of water-soluble threads 6 is less than 1 / 4 of the number of threads extending in the wale direction.

[0060] FIG. 7 is a schematic diagram showing another knitted fabric structure of a fastener tape. FIG. 8 shows the knitted fabric structure shown in FIG. 7 in a state where the water-soluble yarn has dissolved. The knitted structure of FIG. 7 is knitted from a chain stitch yarn 71, a weft insertion yarn 73, and a tricot yarn 74. Of the 16 tricot yarns, one tricot yarn crossing the dividing line SL is a water-soluble yarn 64. Similarly, of the nine weft insertion yarns 73, one weft insertion yarn crossing the dividing line SL is a water-soluble yarn 65. The 16 tricot yarns and nine weft insertion yarns are configured as ground yarns of the ground structure to satisfy the strength required of the fastener tapes 3, 3′. All ground yarns crossing the dividing line SL are water-soluble yarns, and all other yarns are water-insoluble yarns. Therefore, when the water-soluble yarns 64, 65 dissolve, the fastener tapes 3, 3′ are separated into a first tape portion 3a and a second tape portion 3b (see FIG. 8). In the case shown in Figure 7, there are a total of 24 threads extending in the wale direction, of which two are water-soluble threads 6, and the number of water-soluble threads 6 is less than 1 / 12 of the number of threads extending in the wale direction.

[0061] FIG. 9 shows an embodiment in which the fastener tapes 3, 3' are woven fabrics. For example, one warp thread at a dividing line SL is a water-soluble thread 66, and all other warp threads are water-insoluble threads 7. One weft thread is a water-soluble thread 67. The water-soluble thread 66 and the portion of the water-soluble thread 67 intersecting it dissolve, dividing the fastener tapes 3, 3' into a first tape portion 3a and a second tape portion 3b. To dissolve the water-soluble thread 67 only at the portion intersecting the water-soluble thread 66 rather than the entirety, only a portion of the fastener tapes 3, 3' may be immersed in hot water. Even if the water-soluble thread 6 dissolves entirely, the fastener elements 4, 4' remain connected to the warp threads of the multiple water-insoluble threads 7, and the fastener elements 4, 4' do not scatter and require laborious collection. Generally, a woven fabric includes a single weft thread that alternately extends to one side and then the other in the weft direction. When the weft yarn is a water-soluble yarn, it is necessary to take note that the mass of the water-soluble yarn contained in the fastener tapes 3, 3' increases.

[0062] 10 and 11 show fastener tapes 3, 3' in which the first and second tape portions 3a, 3b are sewn together with a water-soluble thread 68. The first and second tape portions 3a, 3b may each be woven or knitted from a water-insoluble thread. The water-soluble thread 68 is a sewing thread that sews together the first and second tape portions 3a, 3b (e.g., their selvage portions). This configuration also provides the same effect as described above. The water-soluble thread 68 is typically a sewing thread. Note that in the case shown in FIG. 10, the water-soluble thread 68 does not intersect with the center line TC, whereas in the case shown in FIG. 11, the water-soluble thread 68 intersects with the center line TC. The configuration shown in FIG. 10 is preferred because the first tape portion 3a is narrower.

[0063] As shown in Fig. 12, the fastener elements 4, 4' may be resin elements. Even if recycling of the article body is difficult, recycling of the fastener elements 4, 4' can be promoted.

[0064] The knitted fabrics shown in Figures 13 and 14 can also be used. Figures 13 and 14 show the state of the fastener tapes 3, 3' before the water-soluble yarn dissolves. The knitted structure in Figure 13 is knitted from a chain stitch yarn 71, a weft insertion yarn 73, a tricot yarn 74, a warp insertion yarn 75, and a reverse insertion yarn 76. Of the 12 tricot yarns, one tricot yarn crossing the dividing line SL is a water-soluble yarn. Similarly, of the 10 weft insertion yarns 73, three weft insertion yarns 73 crossing the dividing line SL are water-soluble yarns. All ground yarns crossing the dividing line SL are water-soluble yarns, and all other yarns are water-insoluble yarns. Therefore, as described above, the fastener tapes 3, 3' are divided into a first tape portion 3a and a second tape portion 3b by the dissolution of the water-soluble yarn. There are a total of 14 yarns extending in the wale direction, of which four are water-soluble yarns, and the number of water-soluble yarns is less than one-third of the number of yarns extending in the wale direction.

[0065] The knitted structure of Figure 14 is knitted from chain stitch yarn 71, satin yarn 72, tricot yarn 74, and warp insertion yarn 75. Of the 11 tricot yarns, one tricot yarn crossing the dividing line SL is a water-soluble yarn, and similarly, of the nine satin yarns 72, three satin yarns crossing the dividing line SL are water-soluble yarns. All ground yarns crossing the dividing line SL are water-soluble yarns, and all other yarns are water-insoluble yarns. Therefore, as described above, the fastener tapes 3, 3' are separated into the first tape portion 3a and the second tape portion 3b by the dissolution of the water-soluble yarn. There are a total of 20 yarns extending in the wale direction, of which four are water-soluble yarns, which is less than one-quarter of the number of yarns extending in the wale direction.

[0066] In light of the above teachings, those skilled in the art can make various modifications to each embodiment and each feature. The reference numerals included in the claims are for reference purposes only and should not be used to limit the interpretation of the claims.

[0067] 1: Slide fastener 2: Fastener stringer 2': Fastener stringer 3: Fastener tape 3': Fastener tape 3a: First tape portion 3b: Second tape portion 4: Fastener element 4': Fastener element 6: Water-soluble thread 31: First side edge portion 31': First side edge portion 32: Second side edge portion 32': Second side edge portion SL: Parting line

Claims

1. A fastener stringer (2, 2') comprising a fastener tape (3, 3') having first and second side edges (31, 31', 32, 32') extending in the longitudinal direction of the fastener tape (3, 3'), and a plurality of fastener elements (4, 4') attached to the first side edge (31, 31'), wherein the fastener tape (3, 3') comprises one or more water-soluble threads (6), and the fastener tape (3, 3') is divisible into a first tape portion (3a) including the first side edge (31, 31') and a second tape portion (3b) including the second side edge (32, 32') in response to dissolution of the one or more water-soluble threads (6).

2. The fastener stringer of claim 1, wherein the fastener tape (3, 3') further comprises a plurality of water-insoluble threads (7), and the number of the one or more water-soluble threads (6) is less than 1 / 2, 1 / 3, or 1 / 4 of the number of the plurality of water-insoluble threads (7).

3. A fastener stringer according to claim 1 or 2, wherein the one or more water-soluble threads (6) are soluble in hot water or high-temperature steam.

4. A fastener stringer as described in any one of claims 1 to 3, wherein the one or more water-soluble threads (6) include all threads that cross a dividing line (SL) relating to the boundary between the first tape portion (3a) and the second tape portion (3b).

5. A fastener stringer according to any one of claims 1 to 4, wherein the one or more water-soluble threads (6) are locally introduced into the ground weave of the fastener tapes (3, 3').

6. A fastener stringer according to any one of claims 1 to 5, wherein the one or more water-soluble threads (6) comprise ground threads of the ground structure of the fastener tapes (3, 3').

7. A fastener stringer according to any one of claims 1 to 6, wherein the one or more water-soluble threads (6) include a plurality of types of ground threads of the ground structure of the fastener tape (3, 3').

8. A fastener stringer according to any one of claims 1 to 7, wherein the fastener tape (3, 3') comprises a knitted fabric.

9. A fastener stringer according to claim 8, wherein the one or more water soluble yarns (6) are introduced within the total width of a predetermined number of adjacent wales of the knitted fabric.

10. A fastener stringer as described in claim 9, wherein the predetermined number of wales is 1 / 2 or less, 1 / 3 or less, or 1 / 4 or less of the total number of wales included in the knitted fabric.

11. A fastener stringer as described in any one of claims 8 to 10, wherein the one or more water-soluble yarns (6) include N (N is a natural number of 2 or more) water-soluble yarns, and each of the N water-soluble yarns extends in the course direction of the knitted fabric so as to connect M (M is a natural number of 2 or more) wales included in the knitted fabric.

12. The fastener stringer of claim 11, wherein the N water soluble yarns include at least one satin yarn or weft-insertion yarn.

13. The fastener stringer according to claim 11 or 12, wherein the N water soluble yarns include at least one tricot yarn.

14. A fastener stringer according to any one of claims 11 to 13, satisfying the formula: M-N=1.

15. A fastener stringer as claimed in any one of claims 1 to 14, wherein the one or more water-soluble threads (6) do not cross a centre line (TC) of the fastener tape (3, 3') extending in the longitudinal direction at a central position of the width of the fastener tape (3, 3').

16. A fastener stringer according to any one of claims 1 to 7, wherein the fastener tape (3, 3') comprises a woven fabric.

17. A fastener stringer as described in any one of claims 1 to 4, wherein the one or more water-soluble threads (6) are sewing threads that sew together the ground tissue of the first tape portion (3a) and the ground tissue of the second tape portion (3b).

18. A fastener stringer according to any one of claims 1 to 17, wherein each fastener element (4, 4') of the plurality of fastener elements (4, 4') is made of metal.

19. A fastener stringer (2, 2') comprising a fastener tape (3, 3') having first and second side edges (31, 31', 32, 32') extending in the longitudinal direction of the fastener tape (3, 3'), and a plurality of fastener elements (4, 4') attached to the first side edge (31, 31'), wherein the fastener tape (3, 3') includes one or more water-soluble threads (6), and a tape portion (3a) including the first side edge (31, 31') with the plurality of fastener elements (4, 4') attached thereto is separable from a remaining portion (3b) of the fastener tape (3, 3') in response to dissolution of the one or more water-soluble threads (6).

20. A method for recovering a plurality of fastener elements (4, 4') attached to a fastener tape (3, 3') of a fastener stringer (2, 2'), comprising: a step of exposing at least a portion of the fastener tape (3, 3') to hot water or high-temperature steam to dissolve one or more water-soluble threads (6) contained in the fastener tape (3, 3'); and a step of separating a tape portion (3a) of the fastener tape (3, 3') to which the plurality of fastener elements (4, 4') are attached from a remainder (3b) thereof in response to the dissolution of the one or more water-soluble threads (6).

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