WO2024084669A1

WO2024084669A1 - Fastener tape and method for manufacturing same, and fastener stringer

Info

Publication number: WO2024084669A1
Application number: PCT/JP2022/039176
Authority: WO
Inventors: 祐一宮崎; 弘樹東谷; 誠人有沢
Original assignee: Ykk株式会社
Priority date: 2022-10-20
Filing date: 2022-10-20
Publication date: 2024-04-25

Abstract

A core section (5) is provided to a side edge section (31) of a fastener tape (3) to which a fastener element (4) is attached. The core section (5) includes at least one core thread (51) and a tubular section (52) that surrounds the at least one core thread (51). The at least one core thread (51) includes a crimped thread that is crimped due to a difference between thermal shrinkage rates of different polymeric materials.

Description

Fastener tape, its manufacturing method, and fastener stringer

This disclosure relates to a fastener tape and a manufacturing method thereof, as well as a fastener stringer.

When the fastener tape of a fastener stringer is sewn to the fabric of a garment or the like with sewing thread, the fastener tape may ripple, resulting in uneven spacing between the fastener elements and resulting in poor meshing of the fastener elements. In order to avoid or suppress this problem, it is desirable to set the fastener stringer in a state in which the stringer bias is positive before sewing to the fabric. In a fastener stringer in a state in which the stringer bias is positive, the fastener tape takes an arch shape in which the side edge to which the fastener elements are attached is curved concavely and the opposite side edge is curved convexly (see Figure 4 of the present application). For convenience of explanation, the degree of the arch shape of the fastener tape in Figure 4 of the present application is exaggerated to a greater extent than in reality. Also, the fastener tape is observed by viewing its main surface (e.g., its upper surface or lower surface) from the front.

In Patent Document 1, which addresses the above-mentioned issue, a thread having a higher elongation recovery rate than other warp threads is arranged adjacent to the outside of the core cord. Even if the fastener tape stretches when the fastener element is attached, the side edge portion tends to return to its original length, and the stringer bias is maintained in a positive state. Patent Document 2 discloses making the length of the warp threads on one side edge portion of the fastener tape relatively longer in order to form an arch shape of the fastener tape (see Figure 4 in the same document).

Unrelated to the above-mentioned problem, Patent Document 3 discloses weaving a braided cord into the woven portion of a fastener tape and bonding the two together by thermal shrinkage of the woven portion. In this document, the braided cord is formed by knitting an outer circumferential knit layer consisting of multiple warp knitted yarns around a core yarn. False twisted yarn and spun yarn are given as examples of the core yarn, and it is described that it is preferable to reduce the stretch in the warp direction (page 6, lines 7-10). Patent Document 4 discloses using a latent shrink-producing polyester fiber as the weft yarn.

JP 2004-229729 A China Utility Model No. 212590695 Japanese Utility Model Application Publication No. 55-422 JP 2006-175129 A

The inventors of this application have discovered a new problem: how to bring the fastener stringer into a positive stringer bias state using a different approach than conventional methods.

A fastener tape according to one embodiment of the present disclosure has a core portion provided at a side edge portion of the fastener tape to which a fastener element is attached, the core portion including at least one core thread and a tubular portion surrounding the at least one core thread, and the at least one core thread includes a shrinkable thread that shrinks in response to the difference in the thermal shrinkage rates of different polymeric materials.

In some embodiments, the core portion includes a total of N (N is a natural number equal to or greater than 2) core yarns as the at least one core yarn, and each of the total N core yarns is the crimpable yarn.

In some embodiments, the shrinkable yarn is a composite yarn formed by bonding together threads made of at least two types of polymeric materials having different thermal shrinkage rates.

In some embodiments, the shrinkable yarn is a composite yarn in which at least two types of polymeric materials with different thermal shrinkage rates are spun together.

In some embodiments, the crimpable yarn crimps in a spiral and/or wavy manner.

In some embodiments, the core portion is a core cord woven into the fastener tape.

In some embodiments, the tubular portion includes a knitted structure in which multiple leather threads are woven.

In some embodiments, except for the at least one core yarn, there is no shrinkable yarn that shrinks in response to the difference in thermal shrinkage rate of different polymeric materials.

A fastener stringer according to another aspect of the present disclosure includes any of the fastener tapes described above and a fastener element attached to the side edge portion of the fastener tape.

A method for manufacturing a fastener tape according to another aspect of the present disclosure includes the steps of forming a fastener tape having a core portion provided on one side edge portion, the core portion including at least one core thread and a tubular portion surrounding the at least one core thread, the at least one core thread including a shrinkable thread that shrinks in accordance with the difference in thermal shrinkage rate of different polymeric materials, and heating the fastener tape so that the shrinkable thread shrinks.

In some embodiments, the method further includes, after the step of heating the fastener tape, a step of stretching the fastener tape along its longitudinal direction so as to reduce the degree of crimping of the crimpable yarn.

In some embodiments, the fastener tape is stretched by running along a path defined by a number of rollers while tension is applied in the longitudinal direction.

In some embodiments, the method further includes, after the step of stretching the fastener tape, a step of reheating the fastener tape to increase the degree of crimping of the crimpable yarn.

In some embodiments, the method further includes a step of dyeing the fastener tape, and the step of reheating the fastener tape is performed during the process of drying the fastener tape by heating.

In some embodiments, after the step of heating the fastener tape, at least one step of reducing the degree of crimp of the crimpable yarn and at least one step of increasing the degree of crimp of the crimpable yarn are performed simultaneously or in that order.

According to one aspect of the present disclosure, it is possible to promote a positive stringer bias for fastener stringers in a manner different from that used in the past.

1 is a schematic front view of a slide fastener according to one embodiment of the present disclosure. 4 is a schematic diagram showing a state in which a fastener element is attached to a side edge portion of a fastener tape. FIG. 1 is a schematic diagram showing the structure of a side edge portion of a fastener tape, in which fastener elements are omitted. FIG. 2 is a schematic front view of a fastener stringer with a positive stringer bias. FIG. 13 is a schematic front view of a fastener stringer showing a state in which the stringer bias has changed from a positive state to a zero state due to shrinkage associated with sewing. FIG. 4 is a schematic diagram showing that the tubular portion of the core is formed in a braided structure. FIG. 2 is an enlarged schematic view of one core yarn. FIG. 2 is a schematic diagram showing two crimped core yarns before heat setting. FIG. 9 is a schematic diagram showing two crimped core yarns after heat setting, which shows an increase in crimp per unit distance (e.g., number of helices per unit distance) compared to FIG. FIG. 2 is a schematic diagram showing a crimpable yarn that crimps in a wavy manner. FIG. 1 is a schematic diagram showing a procedure for carrying out a load test. 13 is a graph showing the results of a load test. 4 is a schematic flowchart showing a method for manufacturing a fastener tape. 4 is a schematic diagram showing a state in which a fastener tape runs along a running path determined by rollers. FIG. 10 is a schematic diagram showing another embodiment in which a crimpable yarn is enclosed as a core yarn in the hollow woven portion of the side edge of the fastener tape. FIG. FIG. 13 is a schematic diagram showing another example in which a core is woven into the fastener tape on the opposite side of the coiled element.

Various embodiments and features will be described below with reference to the drawings. Those skilled in the art will be able to combine the various embodiments and/or features without the need for excessive explanation, and will also be able to understand the synergistic effects of such combinations. In principle, overlapping explanations between embodiments will be omitted. The reference drawings are primarily intended to describe the invention, and have been simplified for the convenience of drawing. Each feature is not only effective for the fastener tape and manufacturing method thereof, and fastener stringer disclosed in this application, but is understood to be a universal feature that is also applicable to various other fastener tapes and manufacturing methods thereof, and fastener stringers not disclosed in this specification.

In this specification, the terms indicating directions, such as the front-rear direction, the left-right direction, and the up-down direction, are referred to. The front-rear direction corresponds to the direction of movement of the slider 9 for opening and closing the slide fastener 1, and corresponds to the longitudinal direction of the slide fastener 1 (or the fastener stringer 2 or the fastener tape 3). The left-right direction is a direction perpendicular to the front-rear direction, and corresponds to the width direction of the slide fastener 1 (or the fastener stringer 2 or the fastener tape 3). The up-down direction is a direction perpendicular to the front-rear and left-right directions, and corresponds to the thickness direction of the fastener tape 3. Of course, the up-down direction does not have to correspond to the vertical direction (direction of gravity). In other words, the terms indicating directions referred to in this specification are understood based on the slide fastener 1, and are unrelated to the vertical direction (direction of gravity).

The configuration of the slide fastener 1 will be described with reference to Figures 1 to 3. Figure 1 is a schematic front view of the slide fastener 1. Figure 2 is a schematic diagram showing the state in which a fastener element 4 is attached to a side edge portion 31 of a fastener tape 3. Figure 3 is a schematic diagram showing the structure of the side edge portion 31 of the fastener tape 3, and the fastener element is omitted in order to illustrate the structure.

The slide fastener 1 is typically a flexible, elongated member that extends in the front-rear direction with a substantially constant left-right width (the same goes for the fastener stringer 2 and fastener tape 3). The slide fastener 1 has a pair of left and right fastener stringers 2, each of which includes a fastener tape 3 and a fastener element 4, and a slider 9 for engaging and disengaging these fastener stringers 2. When the slider 9 advances, the left and right fastener elements 4 attached to the opposing side edges 31 of the left and right fastener stringers 2 mesh with each other, and the left and right fastener stringers 2 are engaged. When the slider 9 advances backwards, the left and right fastener elements 4 are disengaged, and the left and right fastener stringers 2 are disengaged. The slide fastener 1 shown in the figure has an upper stop 81 and a lower stop 82 as options, but both can be omitted. The slider 9 is made of, for example, metal or resin.

The fastener tape 3 is a woven or knitted fabric or a mixture of these, and has high flexibility. The fastener tape 3 has a side edge 31 close to the center line CL of the slide fastener 1 that coincides with the movement trajectory of the slider 9, another side edge 32 away from the center line CL, and a tape main portion 33 provided between these side edges 31, 32. The width W3 of the fastener tape 3 is equal to the sum of the width W31 of the side edge 31, the width W32 of the side edge 32, and the width W33 of the tape main portion 33.

The fastener element 4 comprises an array of resin elements affixed (e.g., via injection molding) to the side edge 31 of the fastener tape 3 (see Figures 1 and 2). Alternatively, the fastener element 4 comprises an array of metal elements crimped to the side edge 31 of the fastener tape 3. Alternatively, other types of fastener elements (e.g., coil elements formed by helically winding a resin monofilament) can be used.

The fastener tape 3 has two tape main surfaces, namely, the tape upper surface 3m and the tape lower surface 3n, which face opposite each other in the vertical direction to determine the thickness of the fastener tape 3 (see FIG. 2). Furthermore, the fastener tape 3 has a ground structure 37 constructed from a large number of tape threads (e.g., a plurality of warp threads 35 (35a, 35b, 35c, 35d, 35e, 35f, etc.) and at least one weft thread 36). The number of warp threads 35 is appropriately set according to the target tape width W3 of the fastener tape 3. The warp threads 35 are aligned in the warp direction, and the weft threads 36 extend in a meandering manner in the weft direction so as to rise and fall relative to the warp threads 35. Each warp thread 35 repeatedly straddles two parts of the weft threads aligned in the weft direction (i.e., running parallel in the weft direction) as one unit (see FIG. 3). Of course, the ground structure 37 is not limited to such a woven structure, and may be a knitted structure.

Note that two-dimensional unevenness is formed on the upper tape surface 3m and the lower tape surface 3n in response to the rise and fall of the weft thread 36. Although this is not necessarily the case, all of the tape threads constituting the fastener tape 3 are spun from polyethylene terephthalate (PET) resin and made of the same material. Advantageously, this PET resin is a plant-derived raw material.

A core portion 5 is provided on the side edge portion 31 of the fastener tape 3 to which the fastener element 4 is attached. The core portion 5 includes at least one (preferably multiple) core thread 51 and a (hollow) tubular portion 52 that surrounds or contains the at least one core thread 51. The core portion 5 protrudes upward from the tape upper surface 3m that defines the thickness of the fastener tape 3, and can protrude downward from the tape lower surface 3n (see Figure 2). The core portion 5 has a portion embedded in the fastener element 4, which increases the attachment strength of the fastener element 4.

In some cases, the core 5 is a core string woven into the fastener tape 3. That is, the core 5 is manufactured as a core string in advance before the fastener tape 3 is woven. The fact that the core 5 is a core string means that even after the core string has been woven into the fastener tape 3, it can be removed as a core string from the fastener tape 3 by releasing the restraint by the weft thread 36. The use of a core string as the core 5 facilitates more precise control of the degree of adhesion between the core thread 51 and the tube portion 52, or the degree of static friction that may occur between the two.

In some cases, a plurality of cores 5 (two in the example of Figures 2 and 3) are combined and provided on the side edge 31. For example, an upper core 5m and a lower core 5n are used as the two cores 5, which are combined in the vertical direction and protrude on both the top and bottom sides. Each of the upper core 5m and the lower core 5n is restrained by the weft thread 36 at a position between adjacent warp threads 35, but the method of fixing the cores in the fastener tape 3 is not limited to this embodiment.

In this embodiment, at least one core thread 51 includes a crimpable thread that has been crimped in response to the difference in the thermal shrinkage rate of different polymer materials. Generally, a thread that has a small elongation in the warp direction is used as a core thread. The inventors of the present application have discovered that, contrary to this common technical knowledge, the use of a crimpable thread as the core thread 51 makes it easier to adjust the stringer bias of the fastener stringer 2 to a positive state. Although the exact mechanism behind this has not been elucidated, one possible reason is that the degree of crimping of the crimpable thread (core thread 51) can be adjusted by stretching the fastener tape 3 after the crimpable thread (core thread 51) has been crimped by heat setting. Another possible reason is that the static friction between the crimpable thread (core thread 51) and the tube portion 52 becomes large, and the degree of crimping of the crimpable thread is difficult to change unless a force such as stretching the fastener tape 3 is applied.

When a shrinkable yarn is used as the core yarn and heat set, the core yarn shrinks to a degree according to (for example, proportional to) the difference in the thermal shrinkage rate of the different polymeric materials. This shrinkage of the core yarn 51 causes the fastener stringer 2 to have a positive stringer bias, and at the same time, the static friction between the core yarn 51 and the tubular portion 52 increases (because the degree of shrinkage of the shrinkable yarn (core yarn 51) increases). Although the stringer bias may become excessively positive when a shrinkable yarn is used as the core yarn 51, this can be adjusted by stretching the fastener stringer 2 along its longitudinal direction. Furthermore, due to the increased static friction between the core yarn 51 and the tubular portion 52, the fastener stringer 2 can maintain an appropriate stringer bias state after the adjustment.

Please note that depending on the degree of shrinkage of the shrinkable yarn due to heat setting, the process of stretching the fastener tape 3 may not be necessary. Also, the process of stretching the fastener tape 3 after heat setting can be carried out at any time and to any degree. It can also be carried out at the sewing stage where the fastener tape 3 of the fastener stringer 2 is sewn to the fabric of the garment after the slide fastener 1 is sold.

To reiterate, by using a crimpable yarn as the core yarn 51, the fastener stringer 2 can easily maintain its current stringer bias in a positive state (unless an external force is applied) based on the static friction between the core yarn 51 and the tubular portion 52. It can also prevent the fastener stringer 2 from changing from a state in which the stringer bias is positive to a state in which the stringer bias is zero during the period from the time of manufacture or sale of the slide fastener 1 to the time of sewing at the sewing factory.

When the fastener tape 3 of the fastener stringer 2 is sewn to the fabric of clothing, etc., the stitching of the sewing thread shown by the dashed line in Figure 5 causes the fastener tape 3 to shrink along the stitching, but because the stringer bias is in a positive state, the side edge 31 of the fastener tape 3 changes from a concave, arc-shaped curved state (Figure 4) to a state extending in a straight line (Figure 5). Thus, the front-to-rear pitch of the fastener elements 4 falls within the allowable tolerance range. The state of the fastener stringer 2 shown in Figure 5 can also be called a state in which the stringer bias is zero.

It has also been confirmed that even when other types of yarn (e.g., false twisted yarn) that exhibit a similar thermal shrinkage rate as the crimpable yarn are used, the stringer bias of the zipper stringer 2 cannot be well controlled in a positive state (compared to the present disclosure). This supports the idea that the zipper stringer 2 can be well controlled to have its stringer bias in a positive state depending not only on the shortening due to thermal shrinkage but also on the shrinkage exerted by the crimpable yarn. Although an illustration of the stringer bias in a negative state is omitted, this refers to a state in which the zipper stringer 2 is warped in the opposite direction to that shown in FIG. 4.

The core 5 may include at least one core yarn 51, totaling N (N is a natural number of 2 or more). Each of the total N core yarns 51 may be a crimpable yarn. The total N core yarns 51 may be a doubled yarn drawn together in the warp direction, or a twisted yarn twisted along the warp direction. In some cases, the core 5 includes only a crimpable yarn as the core yarn 51, while in other cases, the core yarn 51 includes a non-crimpable yarn (e.g., a textured yarn). Note that the term "crimpable yarn" as used in this specification means a yarn that shrinks in response to the difference in the thermal shrinkage rate of different polymeric materials (i.e., does not mean the shrinkability exhibited by false twist textured yarn). False twist textured yarn is typically spun from a single polymeric material and made of a single polymeric material, and has a shrinkability in response to subsequent processing, but does not shrink in response to the difference in the thermal shrinkage rate of different polymeric materials. If non-crimping yarns are included, the number of crimping yarns should be greater than the number of non-crimping yarns.

In some cases, the tubular portion 52 includes a braided structure in which multiple skin threads 52a-52d are braided (see, for example, FIG. 6). Each skin thread 52a-52d is typically a non-shrinkable yarn spun from a single polymeric material. By forming the tubular portion 52 into a braided structure, contact between the core thread 51 and the tubular portion 52 can be ensured regardless of how the core thread 51 shrinks, and it is also possible to tighten the core thread with the skin thread by selecting a skin thread with an appropriate heat shrinkage rate.

Please note that FIG. 6 is a simplified diagram created for explanation purposes. In FIG. 6, a cylindrical virtual space R51 indicates a space in which multiple core threads 51 are arranged. Specific methods for forming a knitted structure in the tubular portion 52 are known to those skilled in the art. For example, four latch needles are arranged in the circumferential direction at equal intervals of 90°, and sheath threads are fed in an eight-shape to the latch needles that face each other at an angle of 180°. Needle loops are formed at positions corresponding to the latch needles. As shown in FIG. 6, the sheath threads with a phase difference of 180° in the circumferential direction are continuously entangled to form the knitted structure.

The shrinkable yarn used as the core yarn 51 is a composite yarn in which

threads

71 and 72 made of at least two types of polymeric materials with different heat shrinkage rates are bonded together, in other words, it can be a composite yarn 7 in which at least two types of polymeric materials with different heat shrinkage rates are spun together (see, for example, FIG. 7). In FIG. 7, the polymeric material of the thread 71 has a first heat shrinkage rate, and the polymeric material of the thread 72 has a second heat shrinkage rate different from the first heat shrinkage rate. The polymeric material of the thread 71 is, for example, PET (polyethylene terephthalate). The polymeric material of the thread 72 is, for example, PTT (polytrimethylene terephthalate). The

threads

71 and 72 are not limited to being bonded adjacent to each other, but may be bonded in a manner in which one is included in the other. It is also possible to spin a shrinkable yarn from three types of polymeric materials with different heat shrinkage rates.

The degree of crimping of a crimpable yarn changes before and after it is crimped. Figure 8 shows a crimpable core yarn before heat setting, and Figure 9 shows a crimpable core yarn after heat setting. As can be seen by comparing the two figures, heat setting increases the degree of crimping per unit distance (e.g., the number of spirals per unit distance). Furthermore, by bundling multiple core yarns 51, each of which is a crimpable yarn, they can be treated as a single composite yarn, as shown by the dotted lines in Figures 8 and 9.

The three-dimensional shape of the crimpable yarn is not limited to a regular helical shape as shown in Figure 8, but may be a random helical shape in which the helical density varies along the length of the yarn. Also, as shown in Figure 10, the crimpable yarn may be wavy rather than helical. It is also conceivable that a single crimpable yarn may have a shape that is helical in one section along its length and wavy in another section, i.e., where helical and wavy shapes appear randomly.

The degree of crimping of a crimpable yarn can be expressed by the number of spiral or wave convexities contained per unit distance (1 cm). When a crimpable yarn crimps in a spiral shape, one convexity corresponds to one turn of the spiral (see the dashed-dotted box in Figures 8 and 9). When a crimpable yarn crimps in a wave shape, one convexity corresponds to one wave (see the dashed-dotted box in Figure 10).

The shrinkable yarn may be limited to the core yarn 51 of the core portion 5. That is, all other yarns in the fastener tape 3 except for the core yarn 51 are non-shrinkable yarns and are spun from a single polymeric material and made of a single polymeric material. In other words, the fastener tape 3 does not contain shrinkable yarns that shrink in response to the difference in the thermal shrinkage rate of different polymeric materials, except for the core yarn 51. In this case, the degree of shrinkage can be easily adjusted by adjusting the number of shrinkable core yarns 51, that is, excessive or insufficient shrinkage can be easily avoided. Just to be clear, if only the core yarn 51 is a shrinkable yarn, the side edge portion 32 and the tape main portion 33 do not contain shrinkable yarns that shrink in response to the difference in the thermal shrinkage rate of different polymeric materials. The side edge portion 31 does not contain shrinkable yarns that shrink in response to the difference in the thermal shrinkage rate of different polymeric materials, except for the core yarn 51. In some cases, the side edge portion 32 is made of warp threads of the same thickness and density as the warp threads of the tape main portion 33, and does not include threads (commonly known as selvage threads) that are thicker than the warp threads of the tape main portion 33. Omitting the selvage threads promotes weight reduction and cost reduction of the fastener stringer.

The load test on the yarn bundle 6, which is a bundle of three heat-set crimped yarns, will be described with reference to Figures 11 and 12. Figure 11 is a schematic diagram showing the procedure for carrying out the load test. Figure 12 is a graph showing the results of the load test. As shown in Figure 11, the yarn bundle 6 is fixed at the upper end point P1 of the test section, hangs down vertically, and has a weight 61 attached to the lower end point P2 of the test section. The amount of displacement of the intermediate point P3, which is halfway between the upper end point P1 and the lower end point P2, was observed before and after the yarn bundle 6 was pulled toward the ground by the weight 61.

The dashed line L1 in Figure 12 shows the load curve when a non-shrinkable yarn is used as the core yarn. The dashed line L2 shows the load curve when a shrinkable yarn with a relatively small heat shrinkage rate is used as the core yarn. The solid line L3 shows the load curve when a shrinkable yarn with a relatively large heat shrinkage rate is used as the core yarn. As seen in L2 and L3, by using a shrinkable yarn as the core yarn, the fastener tape 3 can be stretched more. This means that the length of the side edge portion 31 of the fastener tape 3 after heat setting can be easily adjusted, which is a countermeasure against excessive shrinkage of the core yarn 51.

It is advisable to use a crimpable yarn with an elongation of 7% or more. For example, it is advisable to use a crimpable yarn with an elongation in the range of 7% to 10%. The elongation of the crimpable yarn is evaluated in the load test shown in Figure 11, and specifically, it is calculated as the elongation rate ((stretched length - original length) / original length) x 100 when a weight of a specified mass is attached to a bundle of three crimpable yarns.

The manufacturing method of the fastener tape 3 will be described with reference to FIG. 13. First, the fastener tape 3 with the core 5 is formed (S1). Specifically, the fastener tape 3 is formed with the core 5 provided on the side edge 31. For this purpose, an automatic loom or an automatic knitting machine can be used. When the core 5 is a core string woven into the fastener tape 3, step S1 may include a step of forming the core 5 as a core string and a step of weaving the fastener tape 3 including the core 5. The step of forming the core 5 as a core string may include a step of drawing together a plurality of core threads 51 and a step of forming a tubular portion 52 on the outer periphery of the bundle of the plurality of core threads 51 (see FIG. 6). It is preferable to knit the tubular portion 52 as a knitted structure. In the step of weaving the fastener tape 3 including the core 5, the core 5 is bound by the weft yarn and woven into the fastener tape 3. As shown in FIG. 2 and FIG. 3, a pair of upper and lower cores 5 (core strings) can also be woven into the fastener tape 3.

Next, the fastener tape 3 is heat-set (i.e., heated) so that the shrinkable yarn shrinks (S2). The set temperature for heat-setting depends on the material of the shrinkable yarn, but for example, the set temperature of a heat source such as a heater is set to a temperature within the range of 160°C to 200°C. The heat source and the side edge portion 31 of the fastener tape 3 are placed facing each other at a close distance, and the side edge portion 31 of the fastener tape 3 is heated. Different polymer materials in the shrinkable yarn used as the core yarn 51 thermally shrink to different degrees. As a result, the shrinkable yarn shrinks, the length of the core portion 5 becomes shorter, and the stringer bias becomes positive. A heater can be placed along the transport path of the fastener tape 3. The heater is, for example, an electric heater that generates heat by electrical heating, but other types of heaters can also be used.

Next, a first post-treatment is carried out on the fastener tape 3 (S3). The first post-treatment may include a dyeing process for the fastener tape 3. The fastener tape 3 may be transported to a dyeing tank that stores a dye solution or to the outlet of an inkjet printer for dyeing using multiple rolls (for example,

rollers

101, 102 shown in FIG. 14). The fastener tape 3 travels along a path determined by multiple rollers while tension is applied in its longitudinal direction. This reduces the degree of crimping of the crimpable yarn and weakens the degree to which the stringer bias is positive.

Next, the second post-treatment is carried out on the fastener tape 3 (S4). The second post-treatment may include a drying process for the fastener tape 3. In the drying process, the fastener tape is reheated. A heater can be used for this purpose as described above. If dyeing is carried out in the first post-treatment process, the fastener tape 3 to which the dye solution has adhered or penetrated is dried. In either case, the degree of shrinkage of the shrinkable yarn used as the core yarn 51 is increased by the thermal shrinkage.

After step S2, at least one step of reducing the degree of crimping of the crimpable yarn and at least one step of increasing the degree of crimping of the crimpable yarn may be performed simultaneously or in this order to facilitate the fastener tape 3 being in a state of moderate stringer bias. The first and second post-treatment steps (S3, S4) include a process for reducing the degree of crimping of the crimpable yarn, and a process for increasing the degree of crimping of the crimpable yarn. As a result, even if the stringer bias of the fastener stringer 2 becomes excessively positive in the heat setting step (S2), it can be naturally transitioned to a state of moderate stringer bias through the first and second post-treatment steps.

Steps S3 and S4 are not limited to dyeing and drying steps. When the fastener tape 3 is placed in the cavity of the injection molding die, tension is applied to the fastener tape 3 in its longitudinal direction. The fastener tape 3 is also heated in response to the heat transferred from the molten resin or the die during injection molding. In this case, the first post-treatment step (stretching the fastener tape 3 in the die cavity) and the second post-treatment step (thermal shrinkage of the shrinkable yarn in response to the heat transferred from the die) are carried out simultaneously.

As shown in FIG. 15, it is also possible to form a tubular portion 52 as a hollow weave 38 in part of the ground structure 37 of the fastener tape 3, and introduce a core thread 51 into this tubular portion 52. In this case as well, the same effect as described above can be obtained.

As shown in FIG. 16, a coil-shaped element can also be used as the fastener element 4. The coil-shaped element is sewn to the main tape surface (e.g., the bottom surface) of the fastener tape 3. A core portion 5 is provided on the opposite side of the fastener tape 3. Specifically, one of the core portions in FIGS. 2 and 3 (e.g., only the upper core portion 5m) is woven into the fastener tape 3 (the lower core portion 5n in FIGS. 2 and 3 is omitted). Other configurations are also envisioned.

In light of the above teachings, those skilled in the art may make various modifications to each embodiment. The reference symbols included in the claims are for reference purposes only and should not be used to interpret the claims in a limited manner.

1: Slide fastener 2: Fastener stringer 3: Fastener tape 4: Fastener element 5: Core 7: Composite thread 9: Slider

31: Side edge portion 32: Side edge portion 33: Main portion of tape

35: Warp thread 36: Weft thread 37: Ground weave

51: core thread 52: cylinder portion 52a-52d: skin thread

Claims

A fastener tape in which a core portion (5) is provided on the side edge portion (31) of a fastener tape (3) to which a fastener element (4) is attached, the core portion (5) includes at least one core thread (51) and a tubular portion (52) surrounding the at least one core thread (51), and the at least one core thread (51) includes a shrinkable thread that shrinks in response to the difference in the thermal shrinkage rates of different polymeric materials.
The fastener tape according to claim 1, wherein the core portion includes a total of N (N is a natural number equal to or greater than 2) core yarns as the at least one core yarn, and each of the total N core yarns is the crimpable yarn.
The fastener tape according to claim 1 or 2, wherein the shrinkable yarn is a composite yarn in which threads made of at least two types of polymeric materials with different thermal shrinkage rates are bonded together.
The fastener tape according to any one of claims 1 to 3, wherein the shrinkable yarn is a composite yarn in which at least two types of polymeric materials having different thermal shrinkage rates are spun together.
The fastener tape according to any one of claims 1 to 4, wherein the crimpable yarn crimps in a spiral and/or wavy shape.
The fastener tape according to any one of claims 1 to 5, wherein the core portion is a core cord woven into the fastener tape.
The fastener tape according to any one of claims 1 to 6, wherein the tubular portion includes a braided structure in which multiple leather threads are woven.
The fastener tape according to any one of claims 1 to 7, which does not contain any shrinkable yarn that shrinks in response to the difference in the thermal shrinkage rate of different polymeric materials, except for the at least one core yarn.
The fastener tape according to any one of claims 1 to 8,
A fastener stringer including a fastener element attached to the side edge of the fastener tape.
A process for forming a fastener tape having a core portion provided on one side edge portion, the core portion including at least one core thread and a tubular portion surrounding the at least one core thread, the at least one core thread including a crimpable thread that is crimped in accordance with a difference in thermal shrinkage rate between different polymer materials;
A method for producing a fastener tape, comprising the step of heating the fastener tape so that the crimpable yarn is crimped.
The method for producing a fastener tape according to claim 10, further comprising the step of stretching the fastener tape along its longitudinal direction so as to reduce the degree of crimping of the crimpable yarn after the step of heating the fastener tape.
The method for manufacturing a fastener tape according to claim 11, wherein the fastener tape is stretched by running along a running path defined by a plurality of rollers while tension is applied in the longitudinal direction of the fastener tape.
The method for producing a fastener tape according to claim 11 or 12, further comprising a step of reheating the fastener tape after the step of stretching the fastener tape so as to increase the degree of crimping of the crimpable yarn.
The method for producing a fastener tape according to claim 13, further comprising a step of dyeing the fastener tape, and the step of reheating the fastener tape is carried out during the process of drying the fastener tape by heating.
The method for producing a fastener tape according to claim 10, wherein after the step of heating the fastener tape, at least one step of reducing the degree of crimp of the crimpable yarn and at least one step of increasing the degree of crimp of the crimpable yarn are carried out simultaneously or in this order.