Elastic hair band and method for producing elastic hair band

Abstract

[Problem] To provide an elastic hair band that is highly biodegradable even when discarded and that will not be broken even when a large tensile strength acts during use thereof. [Solution] The present invention comprises: a base material preparation step for preparing a base material by weft knitting using covering threads; and a heat treatment step for causing the base material to shrink through a heat treatment on the base material.

Description

Hair tie and method for manufacturing the hair tie

[0001] The present invention relates to a hair tie and a method for manufacturing a hair tie.

[0002] Hair ties are now widely used to hold hair in place. These hair ties have traditionally been manufactured by wrapping a string-like core material made of synthetic or natural rubber in a nylon or polyester fabric, forming it into a ring shape, and adhesively securing both ends of the core material.

[0003] In this case, synthetic rubber and nylon polyester are synthetic resins, and adhesives are often made of synthetic resins such as synthetic polyvinyl acetate and epoxy resin. Because synthetic resins are derived from petroleum, discarded conventional hair ties are less biodegradable and cannot be decomposed by bacteria or fungi, leading to environmental pollution. As a result, discarded hair ties have traditionally been a source of environmental pollution. This issue is likely to continue as environmental awareness grows. Furthermore, conventional hair ties are formed by bonding both ends of a string-like hair tympanic base material with an adhesive. If a large axial pulling force is applied depending on how the hair tympanic is used, the bonded portion may come off, rendering the hair tympanic unusable. Furthermore, the adhesive at the bonded portion of the hair tympanic hardens, making it hard and uncomfortable to the touch when wrapped around the wrist, for example. Based on this perspective, the applicant searched prior patent documents and identified the following documents:

[0004] Patent Document 1: Japanese Patent No. 3560602 Patent Document 2: Utility Model Registration No. 3061177

[0005] The invention described in Patent Document 1 is a method for manufacturing a ring-shaped or string-shaped elastic band by joining the end faces of one or more rubber-cored strings, which have a rubber core covered with an elastic fiber cover.The method includes the steps of: applying a solidifying agent, which is mixed with water and has the effect of solidifying the rubber-cored string, water, and an expander such as sodium bicarbonate or yeast powder, directly to the end face, including the end face of the rubber core, of the rubber-cored raw string, solidifying the end face of the rubber core and the end face of the elastic cover together and forming the solidified portion into a porous shape through the action of the expander; cutting the solidified portion of the raw string flat to obtain the rubber-cored string; and butting the cut end faces of the rubber-cored string together with a water-insoluble adhesive, penetrating the adhesive into the holes exposed on the cut end faces to bond the end faces together and connect the rubber-cored strings.

[0006] This invention aims to improve the tensile strength of the adhesive joint, but does not meet the above-mentioned demands for biodegradability or the discomfort felt at the joint when worn. Furthermore, the invention described in Patent Document 2 is a far-infrared emitting ceramic inner packaging accessory in which porous ceramic particles with high far-infrared emissivity are enclosed in an accessory such as a bracelet, hair band, or waist belt, at least a portion of which is formed into a pouch-shaped band, and similarly does not meet the above-mentioned demands.

[0007] The problem to be solved by the present invention is to provide a hair tie that is highly biodegradable and naturally recyclable, even when discarded, so that environmental pollution can be avoided, and that will not break even when subjected to a large tensile strength during use, and a method for manufacturing the same.

[0008] The invention of claim 1 is a hair tie made by heat-treating a base material made by weft-knitting a covering yarn and shrinking it. Unlike conventional methods, where both ends of a string-like hair tie base material are joined with adhesive, the hair tie made by this method is made by weft-knitting the entire base material as a single unit. Therefore, even if a large tensile force is applied in the longitudinal direction during use, the lack of a joint as in conventional methods prevents breakage at the joint.

[0009] As a result, it is possible to provide a hair tie with greater tensile strength than conventional hair ties and able to withstand heavy use. Furthermore, because there are no adhesive joints, even when worn on the hand, the hard, solidified joints do not come into contact with the skin as in conventional cases, providing a comfortable fit. Furthermore, because the hair tie is formed simply by subjecting a weft-knitted substrate to a heat treatment to shrink the substrate, there is no need for the conventional adhesive bonding process, making it possible to easily and quickly produce hair ties.

[0010] The invention of claim 2 is a hair tie characterized in that the covering yarn is composed of a core yarn that is both biodegradable and stretchable, and a biodegradable sheath yarn that covers the core yarn. Therefore, the core yarn and sheath yarn used to make the hair tie are both made of biodegradable materials, and the entire base material is integrally formed by weft knitting with the covering yarn made of the core yarn and sheath yarn, so even if it is discarded, it exhibits good biodegradability and prevents environmental pollution.

[0011] The invention of claim 3 is a hair elastic characterized in that the core yarn is made of natural rubber or biodegradable polyurethane, and the sheath yarn is made of cotton or rayon. Therefore, since the core yarn and sheath yarn that make up the covering yarn are both made of biodegradable materials, they exhibit good biodegradability even when discarded, preventing environmental pollution. Furthermore, since the natural rubber core yarn is covered by the cotton or rayon sheath yarn, the core yarn does not come into direct contact with the user's skin or scalp, and even if the user has a rubber allergy, they can use the hair elastic without developing a rubber allergy.

[0012] The invention of claim 4 is a hair tie characterized in that the weft knitting is a plain knitting using a plain stitch method, and curling sections that turn up toward the back side are formed on both ends of the width of the base material. Since plain knitting is a flat knitting method that is highly stretchable in the lateral direction, it is possible to provide a hair tie with even greater stretchability in addition to the effects of the invention of claim 9.

[0013] Furthermore, a characteristic of jersey knitting is that the widthwise edges of the substrate tend to curl up toward the backside, a phenomenon known as "curling." As a result, this curling phenomenon can be used to appropriately prevent fraying of the yarn at both ends of the substrate, while simultaneously treating the side edges for use as a hair tie by curling both widthwise edges of the substrate inward. This allows the finished hair tie to be quickly obtained after a heat treatment process.

[0014] In the invention described in claim 5, the hair tie is characterized in that it is produced by turning the base material over so that the curling portion is positioned on the inner side.

[0015] Therefore, it is possible to create a hair tie by turning the substrate that has been shrunk by the heat treatment over and positioning the curling portion that was located on the outside of the substrate on the inside.

[0016] According to the invention of claim 6, the covering yarn is composed of a core yarn that is both biodegradable and stretchable and a biodegradable sheath yarn that covers the core yarn, the weft knitting is flat knitting or circular knitting, the base material is an elongated base material, and the hair tie is produced by cutting the elongated base material in the width direction to produce cut base material and then subjecting the cut base material to the heat treatment. Therefore, the hair tie can be produced by heat treating the cut base material formed by cutting the elongated base material along the width direction.

[0017] The invention of claim 7 is a hair tie characterized in that the core thread is made of natural rubber or biodegradable polyurethane, and the sheath thread is made of cotton or rayon. Therefore, since both the core thread and sheath thread that make up the covering thread are made of biodegradable materials, they exhibit good biodegradability even when discarded, preventing environmental pollution. Furthermore, because the natural rubber core thread is covered by the cotton or rayon sheath thread, the core thread does not come into direct contact with the user's skin or scalp, and even if the user has a rubber allergy, they can use the hair tie without developing a rubber allergy.

[0018] The eighth aspect of the present invention provides a hair tie made using plain knitting, with curled sections formed on both widthwise ends of the cut substrate, which turn toward the backside. Plain knitting is a flat knitting method that provides excellent lateral stretch, making it possible to provide a hair tie with even greater stretch. Furthermore, a characteristic of plain knitting is that both widthwise edges of the substrate curl toward the backside, creating curled sections due to the "curling phenomenon." These curled sections effectively prevent fraying of the yarn at both ends of the substrate, and simultaneously process the side edges of the substrate by curling inward at both widthwise ends. Heat treatment allows for the finished hair tie to be quickly produced.

[0019] The invention of claim 9 is a hair tie that is made by turning the base material over so that the curling part is positioned on the inside. Therefore, the hair tie can be made by turning the base material that has been shrunk by the heat treatment over so that the curling part that was positioned on the outside of the base material is now positioned on the inside.

[0020] The invention of claim 10 is a hair tie that is colored with a dye derived from natural sources. Therefore, even when coloring a hair tie, the dyes used are naturally derived, and unlike common synthetic (chemical) dyes, the dyes themselves have natural reducing properties, making it possible to provide a hair tie that is kind to the human body and the environment, even when colored.

[0021] The invention described in claim 11 is a method for manufacturing a hair tie, characterized by comprising a base material creation step of creating a base material by weft knitting using covering yarn, and a heat treatment step of heat treating the base material to shrink it.

[0022] The hair ties produced using this manufacturing method are not formed by joining both ends of a string-like hair tie base material with adhesive as in conventional methods, but rather the entire base material is formed as a single unit through weft knitting.As a result, even if a large tensile force is applied in the longitudinal direction depending on the usage conditions, the hair ties do not have a joint like in conventional methods, and therefore the situation where they break at the joint can be avoided.

[0023] As a result, it is possible to provide a hair tie with greater tensile strength than conventional hair ties and able to withstand heavy use. Furthermore, because there are no adhesive joints, even when worn on the hand, the hard, solidified joints do not come into contact with the skin as in conventional cases, providing a comfortable fit. Furthermore, because the hair tie can be manufactured simply by subjecting the weft-knitted substrate to a heat treatment to shrink the substrate, eliminating the need for the conventional adhesive process, making it possible to easily and quickly produce hair ties. As a result, hair ties can be easily produced using only the substrate production process and heat treatment process.

[0024] In the invention described in claim 12, there is provided a method for manufacturing a hair tie, characterized in that the covering yarn is made by covering a core yarn that is both biodegradable and stretchable with a sheath yarn that is also biodegradable.

[0025] Therefore, the core yarn and sheath yarn that make up the covering yarn used in this manufacturing method are both made of biodegradable materials, and the entire base material is integrally formed by weft knitting, so even if it is discarded, it exhibits good biodegradability and prevents environmental pollution. Furthermore, by using a covering yarn with a core material made of a stretchy material, the stretch and strength required for a hair tie can be obtained.

[0026] According to the invention of claim 13, there is provided a method for manufacturing a hair tie, in which the core yarn is made of natural rubber or biodegradable polyurethane, and the sheath yarn is made of cotton or rayon, and the hair tie is produced by flat knitting. Because the natural rubber core yarn is covered with the cotton or rayon sheath yarn, the core yarn does not come into direct contact with the user's skin or scalp, making it possible to provide a hair tie that can be used without causing an allergic reaction even if the user is allergic to rubber.

[0027] The invention of claim 14 is a method for manufacturing a hair tie, wherein the flat knitting is plain knitting, and curling occurs at the edge of the base material in the base material preparation step.

[0028] "Jersey knitting" is a flat knitting method that is highly stretchable in the horizontal direction, and in addition to the effect of the invention of claim 2, it is possible to provide a hair tie with even greater stretch. Furthermore, a characteristic of jersey knitting is that substrates made with jersey knitting experience a "curling phenomenon," in which both widthwise edges of the substrate curl up toward the backside. Therefore, by utilizing this curling phenomenon, it is possible to appropriately prevent fraying of the yarn at both ends of the substrate, and simultaneously process the side edges for use as a hair tie by curling both widthwise edges of the substrate inward. This allows for a quick production of a finished hair tie after a heat treatment process.

[0029] According to the invention of claim 15, there is provided a method for manufacturing a hair tie, which comprises turning the base material created in the pre-heating process over so that the curling portion is positioned on the inside. Therefore, by turning the base material created in the pre-heating process over so that the curling portion is positioned on the inside, it is possible to easily create a finished hair tie.

[0030] The invention described in claim 16 is a method for manufacturing a hair tie, characterized in that the base material is created to a size that will result in a finished product with the diameter and height dimensions, assuming the diameter and height dimensions of the finished product, after being thermally shrunk by a heat treatment process.

[0031] Although an accurate molecular explanation for this "thermal shrinkage of fibers" has not yet been established, it is believed that it is often caused by the release of internal residual strain in the fibers. It is generally understood that this is due not only to dimensional changes in the fibers themselves, but also to changes in fiber morphology. Therefore, by using a flat knitting machine, simply by inputting the diameter and width dimensions of the finished product, it is possible to create a base material that will undergo thermal shrinkage during the heat treatment process, and then quickly and easily manufacture a hair tie through the heat treatment process.

[0032] The invention described in claim 17 is a method for manufacturing a hair tie, wherein the hair tie is made by flat knitting or circular knitting, the core yarn is made of natural rubber or biodegradable polyurethane, and the sheath yarn is made of cotton or rayon, and the base material is an elongated base material, and the method further comprises a step of cutting the base material to a predetermined width dimension along the width direction to produce a plurality of cut base materials, and a heat treatment step of heat treating the cut base materials to shrink them.

[0033] In the present invention, the substrate to be produced is an elongated substrate, and in the cutting process, the elongated substrate is cut in the width direction to produce the cut substrate, and in the heat treatment process, the cut substrate is subjected to heat treatment to produce the hair tie.

[0034] The invention of claim 18 is a method for manufacturing a hair tie, characterized in that the flat knitting is a jersey knit, and curling occurs at the widthwise edges of the cut substrate after cutting in the cutting process. Plain knitting is a flat knitting method that is highly stretchable in the widthwise direction, making it possible to provide a hair tie with even greater stretchability in addition to the invention of claim 5. Furthermore, when knitted using jersey knitting in the heat treatment process, the edges of the substrate tend to curl up toward the back side along the width of the substrate. By utilizing this curling phenomenon, it is possible to appropriately prevent fraying of the yarn at both ends of the substrate, roll both ends of the substrate inward, and simultaneously process the side edges into a hair tie, allowing the finished hair tie to be produced instantly.

[0035] The nineteenth aspect of the present invention is a method for manufacturing a hair tie, further comprising a coloring step using a dye derived from natural sources. Therefore, even when coloring hair ties, the dyes used are naturally derived, and unlike common synthetic (chemical) dyes, the dyes themselves have natural reducing properties, making it possible to provide hair ties that are gentle on the human body and the environment, even when colored.

[0036] Therefore, the present invention provides a hair tie that will not break even when subjected to a large tensile strength during use, and that is highly biodegradable and naturally recyclable, even when discarded, thereby preventing environmental pollution.

[0037] 1 is a block diagram showing one embodiment of a method for manufacturing a hair tie according to the present invention; FIG. 2 is an explanatory diagram showing an example of a process for producing a covering yarn in the method for manufacturing a hair tie according to the present invention; FIG. 3 is a diagram showing a knitting structure of flat jersey knitting, which is an example of weft knitting used in the method for manufacturing a hair tie according to the present invention, where (a) is a conceptual diagram showing the knitting structure of the front side of the knitted fabric, and (b) is a conceptual diagram showing the knitting structure of the back side of the knitted fabric; FIG. 4 is a perspective view showing an example of a flat knitting machine used in manufacturing a hair tie according to the present invention; FIG. 5 is a diagram showing an example of a substrate produced by a flat knitting machine in the method for manufacturing a hair tie according to the present invention; FIG. 6 is a perspective view showing a state in which the shape of the substrate produced by the method for manufacturing a hair tie according to the present invention has been adjusted; FIG. 7 is a perspective view showing a state in which the shape of the substrate produced by the method for manufacturing a hair tie according to the present invention has been adjusted, subjected to a heat treatment to cause thermal shrinkage, and turned over to produce the hair tie according to the present invention; FIG. 8 is a block diagram showing another embodiment of a method for manufacturing a hair tie according to the present invention; FIG. 9 is a diagram showing a substrate according to another embodiment produced by a flat knitting machine in the method for manufacturing a hair tie according to the present invention.

[0038] An embodiment of the present invention will now be described with reference to the accompanying drawings. As shown in Figures 2, 5 to 7, the hair tie 100 according to this embodiment is manufactured by heat-treating a base material made by weft-knitting a covering yarn 10 to cause it to shrink. The covering yarn 10 is composed of a core yarn 11 that is biodegradable and stretchable, and a sheath yarn 12 that covers the core yarn 11 and is also biodegradable. The core yarn 11 is made of natural rubber, and the sheath yarn 12 is made of cotton or rayon.

[0039] In this embodiment, the "weft knitting" is a weft knitting using a plain stitch method, and curling portions 25, 25 that turn up toward the back side are formed on both ends of the width of the base material 18. The base material 18 is then turned over so that the curling portions 25, 25 are positioned on the inward side.

[0040] Such a hair tie 100 is manufactured by the following manufacturing method. As shown in Figure 1, the manufacturing method of the hair tie according to this embodiment includes a step S1 in which a core yarn that is both biodegradable and stretchable is covered with a biodegradable sheath yarn to create a covering yarn, a base material creation step S2 in which a base material is created using a weft knitting machine using the covering yarn, and a heat treatment step S3 in which the base material is heat-treated to shrink it. Unlike conventional hair ties, the hair tie according to this embodiment is formed by knitting. Each step will be explained below.

[0041] [Covered Yarn Production Process] As shown in Figure 2, the covered yarn 10 is a composite textured yarn constructed by twisting a sheath yarn 12 clockwise and counterclockwise around a core yarn 11 to cover it. In this embodiment, the core yarn 11 is made of natural rubber. When producing the covered yarn 10, a core yarn roll 11a wound in a roll shape is set horizontally so as to be rotatable on a horizontally disposed rotation shaft 14, and the core yarn 11 is pulled out via a pre-draft roller 13 by a drive device (not shown).

[0042] In this embodiment, the sheath yarn 12 is made of cotton or rayon, and the sheath yarn roll 12a wound in a roll shape is set vertically on a hollow spindle 16 having a rotation axis 15 arranged perpendicular to the rotation axis 14 of the core yarn 11. The core yarn 11 is inserted and passes continuously through the interior of the hollow spindle 16, and the hollow spindle 16 rotates in synchronization with the rotation axis 14 of the core yarn roll 11a. In this embodiment, organic cotton is used as the cotton material for the sheath yarn 12. "Organic cotton" refers to cotton produced through organic cultivation, which meets global standards set by the government and is certified as organic cotton. Therefore, the health and environmental impacts caused by the use of chemical products are minimized.

[0043] In conventional cotton cultivation, many chemicals and pesticides, such as those used for pest control and defoliants, are used during the cultivation process, placing a significant burden on the soil and water quality. In contrast, organic cotton is cultivated with due consideration given to environmental safety, significantly reducing the possibility of soil and water contamination. Furthermore, organic cotton cultivation standards include regulations on worker safety and health during the cultivation process, as well as child labor, making it a material that is friendly to both humans and the earth, not just in terms of the safety of the finished product, but also of the people involved. In this state, the core yarn 11, pulled out from the core yarn roll 11a, is twisted with the sheath yarn roll to produce the covered yarn 10. Twisting means "twisting different types of yarn together," and in this embodiment, a core yarn 11 made of natural rubber is continuously twisted with a sheath yarn 12 made of cotton or rayon, and the sheath yarn 12 is wound around the core yarn 11 to cover the core yarn 11, thereby forming a covering yarn 10. The covering yarn 10 is stored as a covering yarn roll 10a.

[0044] [Substrate Creation Process] In the substrate creation process S2, the covering yarn 10 produced in the covering yarn creation process S1 is used by a computer-controlled flat knitting machine to create a substrate for producing the final product, the hair tie 100.

[0045] In this embodiment, the base material 13 from which the hair tie 100 is made is knitted by a computer-controlled flat knitting machine. In this embodiment, for example, a Shima Seiki "WHOLEGARMENT (registered trademark) flat knitting machine SWG041" is used. With this flat knitting machine, the covering yarn 10 is set, and the covering yarn 10 is used to "flat knit" with multiple needles provided in the knitting section. <Regarding flat knitting>

[0046] A flat knitting machine is basically configured to knit a single knitting yarn in a reciprocating motion. Compared to a circular knitting machine that is also capable of weft knitting, which will be described in other embodiments, it is possible to knit knitted structures with very complex structures. A flat knitting machine can knit knit products that require complex knitting structures, highly fashionable sweaters, etc. Therefore, the substrate 18 according to this embodiment can be produced by a flat knitting machine.

[0047] "Weft knitting" is a knitting method in which stitches of yarn are knitted back and forth horizontally, resulting in high stretchability in the left-right direction. As shown in Figure 3, in "weft knitting," horizontal stitches (called "courses" or "loops") are formed by a single weft yarn 17. These are formed along the width and width directions of the fabric being made, with one "course" (or "loop") being formed at a time. A knitted fabric is formed by creating stitches horizontally and connecting the completed course vertically. Vertical stitches are called "wales." The knitted fabric in this embodiment is "plain knit," with the same stitches continuing horizontally. In plain knit, the knitting structure is different between the front and back sides of the knitted fabric, as shown in Figures 3(a) and 3(b). Therefore, the difference between the front and back sides of the knitted fabric is clear, with vertical streaks visible on the knitted fabric and the purl knit appearing somewhat rough. <Knitting Machine>

[0048] To produce the substrate 18 according to this embodiment as described above, a "WHOLEGARMENT (registered trademark) flat knitting machine SWG041 (manufactured by Shima Seiki Mfg. Co., Ltd.)" 19 shown in Figure 4 is used. The flat knitting machine 19 includes a knitting section 20 having a number of knitting needles arranged in a horizontal direction that engage and knit a supplied knitting yarn, a yarn carrier section 21 that appropriately positions the knitting yarn along the length of the device, a drive section and a control section (not shown), a touch panel operation section 23 consisting of a 10.4-inch LCD display, and a yarn stand section 22. The flat knitting machine 19 also includes CAD software for creating design drawings for producing knitted products using the flat knitting machine 19. This CAD software is installed separately on a dedicated personal computer, and design condition data such as the diameter and length of the substrate to be produced, the yarn to be used, the color, the knitting speed, the front stitch, the back stitch, and the coarseness of the stitches can be appropriately set in advance on the CAD software.

[0049] The appropriate knitting speed varies depending on the material. The sheath yarn constituting the covering yarn used in the base material according to this embodiment can be either organic cotton or rayon. When using rayon, the knitting speed can be set faster than when using organic cotton. Meanwhile, the coarseness of the stitches can be set finer when using organic cotton than when using rayon. Other than this, there are no other differences in the base material design stage depending on the yarn material. The knitting coarseness and knitting speed conditions are important points when producing the base material according to this embodiment. Furthermore, the size condition values ​​when producing the base material according to this embodiment can be set appropriately based on the intended size of a circular hair tie (e.g., as shown in Figure 7). Since the diameter of a hair tie is generally approximately 5 cm, the number of needles required to produce a hair tie of this size is set. In this embodiment, the diameter is set to 80 knitting needles, and the height of the hair tie body is set to 134 dots.

[0050] In this way, when the design condition data for the base material is determined separately on CAD software, the basic operation control conditions for the flat knitting machine 19 can be set by inputting the design data via a USB memory or a network, and subsequent operation corrections can be made by appropriately correcting the data using the touch panel operation unit 23, after which the base material is knitted.

[0051] In the knitting section 20, although not shown, a large number of sliding knitting needles are closely arranged along the horizontal direction of the main body of the flat knitting machine 19, and the yarn carrier section 21 is composed of a self-propelled carrier driven by an appropriate drive device, and is configured to appropriately supply knitting yarn consisting of the covering yarn 10 stretched by the yarn holding section 22 to the knitting needles.

[0052] In this embodiment, when knitting is performed by the flat knitting machine 19 using the covering yarn 10, a base material 18 is produced in accordance with the above-mentioned design condition data and is discharged from a discharge hole 24 provided on the front of the flat knitting machine 19. As shown in Fig. 5, the produced base material 18 is formed as a slightly twisted, rectangular fabric material in plan view. Note that Fig. 5 shows the case where two base materials 18 are produced. The base material 18 has a rectangular plan view in which two pieces of fabric material, which are continuous at both ends in the length direction, are continuous at both ends in the diameter direction and overlap in the thickness direction.

[0053] In this embodiment, the surface shown in the drawing is the back side 26. The reason for the twist in the longitudinal direction is that curled portions 25, 25 are formed at both ends of the substrate 18 in the width direction due to the "curling phenomenon." [Regarding the curling phenomenon]

[0054] Curling is a phenomenon that commonly occurs in "jersey knitting." Academically, it is understood that the reason for this phenomenon is due to the loops that form the jersey knitting. That is, in jersey knitting, curling occurs in the left-right direction (in this embodiment, the width direction of the base material 18), which is perpendicular to the knitting direction of the fabric knitted by jersey knitting. The cause of this curling is believed to be due to the mechanical characteristics resulting from the "loop structure" unique to jersey knitting, and although a clear academic theory has not yet been established, the occurrence of this phenomenon is empirically understood in the industry.

[0055] In this embodiment, as shown in Figure 5, the back side 26 of the base material 18, which is a knitted fabric, is exposed to the outside, and curling portions 25 are formed on the back side 26 along the length at both widthwise ends, and the main body of the base material 18 is twisted along the length due to the curling stress of these curling portions 25. In this state, the width dimension of the base material 18 is about 2 to 3 cm, and the length dimension is about 8 to 10 cm. [Heat Treatment Step]

[0056] Next, in the heat treatment step S3, the base material 13, which is the precursor material for the hair tie, is heat-treated. A known steam iron is used for the heat treatment, and heat and pressure are applied by combining the heat and pressure of the iron's ironing surface with steam heating. This heat treatment causes the base material 18 to shrink due to heat. Academically, the reason for this thermal shrinkage is understood to be a change in the knitted fiber morphology itself, i.e., the release of internal residual strain in the fibers, or a change in the supramolecular structure of the fibers.

[0057] In a specific work process, the substrate 18 discharged from the flat knitting machine 19 is transferred onto a work table. In this state, as shown in Fig. 5, the back side 26 of the substrate 18 is exposed to the outside, and the curled portions 25 are also exposed to the outside. In the heat treatment step S3, first, as shown in Fig. 6, the curled portions 25, 25 of the substrate 18 in the state shown in Fig. 5 are manually stretched in the width direction to unfold the entire substrate 18, and the substrate 18 is formed into a belt-like shape of a predetermined width. In this state, the substrate 18 is checked for holes or frayed knitting yarns due to imperfections in the knitting process.

[0058] 6, the substrate 18 is expanded radially into an ellipse and placed upright on a work table, and steam is supplied to the substrate 18 from above using a steam iron. The steam temperature is set to approximately 120 to 143°C. It is also possible to subject the substrate 18 to a heat treatment as is, without placing the substrate 18 upright on a work table in the expanded radially ellipse state, and then perform adjustment work such as shaping the substrate.

[0059] This heat treatment causes the substrate 18 to thermally shrink, and the curling portions 25, 25 curl inward in the width direction of the belt-like substrate 18, until they almost touch each other. The heat-shrunk substrate 18 is stretched radially to shape, and then the front and back of the substrate 18 are inverted radially. In this state, the front and back are inverted, so the curling portions 25, 25 are positioned on the inside and the front side of the substrate 18 appears on the outside. This inversion process completes the substrate 18 as a hair tie 100. As shown in Figure 7, when completed as a hair tie, the diameter of the approximately circular shape in plan view is approximately 5 to 6 cm, and it can be stretched to fit through a user's hand and worn by wrapping it around the wrist.

[0060] In Figure 7, as a result of the inversion, the curling portions 25, 25 formed on the back side 26 of the base material 18 are now positioned inside the annular hair tie 100 so that they are facing each other in the width direction, and the front side 27 of the base material 18 is positioned on the outside. In this state, the hair tie 100 can be used as it is.

[0061] Therefore, in the method of manufacturing a hair tie according to this embodiment, as described above, the base material 18 is made using plain knitting on the flat knitting machine 19, and during this production process, a curling phenomenon occurs, forming curled portions 25, 25 at both widthwise ends of the base material 18. Then, in the heat treatment step S3, the entire base material 18 is heated and shrunk, so that the curled portions 25, 25 also come into contact with each other in the widthwise direction, and in this state, by manually turning the base material 18 over, the front side 27 of the base material 18 is positioned on the outside and the curled portions 25, 25 are positioned on the inside, and therefore the hair tie 100 is produced without any need for sewing or other work as with conventional hair tie.

[0062] As a result, it is possible to quickly and easily create hair ties, overcome the conventional problem of the adhesive bonded areas hardening and coming into contact with the skin when worn, and provide a comfortable wearing experience for the user.

[0063] The hair tie 100 thus produced has a covering yarn 10 formed from a core yarn 11 made of natural rubber and a sheath yarn 12 made of rayon or organic cotton, making it highly biodegradable. Even when discarded after use, it is completely biodegraded and returned to the soil, making it environmentally friendly. In this respect, it is far more environmentally friendly than conventional hair ties made from synthetic rubber or nylon polyester materials and using adhesives made from synthetic resins such as synthetic polyvinyl acetate and epoxy resin.

[0064] In this embodiment, the core yarn 11 is made of natural rubber, but the present invention is not limited to this and may be made of biodegradable polyurethane. Even when a core yarn made of biodegradable polyurethane is used, it is possible to ensure a certain degree of good natural reducibility.

[0065] Furthermore, by using natural rubber or biodegradable polyurethane for the core yarn, it is possible to ensure the elasticity of the entire covering yarn, resulting in the same elasticity as conventional hair ties. Furthermore, since the core yarn is covered by twisting the sheath yarn, it is possible to ensure a certain level of strength and also to prevent the knitting yarn from fraying when the product is completed.

[0066] When biodegradable polyurethane is used for the core thread, it can ensure great elasticity, and like natural rubber, it can stretch 5 to 8 times its normal length when pulled. It also has the property of gradually returning to its original shape after being stretched. Furthermore, it is more resistant to ultraviolet rays and heat than natural rubber, and is stronger than natural rubber.

[0067] Furthermore, in this embodiment, the core thread 11 made of natural rubber is covered with the sheath thread 12 made of organic cotton or rayon, so that even when worn by a user with a rubber allergy, the onset of a rubber allergy can be prevented. Note that, although this embodiment has been described using organic cotton or rayon as the sheath thread, this is not limited to this embodiment, and natural materials such as hemp, flax, linen, ramie, ramie, wool, bamboo, goat hair, mohair, camel hair, alpaca hair, rabbit hair, and protein-derived threads (spider hair, bagworm hair, silk) may also be used.

[0068] [Experimental Example] The applicant of the present patent application requested a third-party testing organization (Nissenken Quality Evaluation Center, Chubu Branch, General Incorporated Foundation) to obtain test data on the hair tie 100 according to the present embodiment, mainly to compare the "tensile strength" with conventional products. The details and results are shown in Table 1 below.

[0069] 1. Test Details The "tensile strength" (unit: N) and "elongation" (%) of seven hair ties, including the hair tie 100 according to the present embodiment and a conventional hair tie, were measured before and after a hydrolysis-promoting treatment (jungle test). The "tensile strength test" measured the strength (N) and elongation (%) of the hair tie when it broke by pulling it with a testing machine. The hair ties 100 according to the present embodiment used in this test were Example Product 1 (trade name "Meriya") and Example Product 2 (trade name "Joker"). Data was collected for Example Product 1, Example Product 2, and Comparative Example 1 (trade name "NADOA") both before and after the jungle test. The "tensile strength" and "elongation" measurements were performed according to JIS L 1096 Method A. The grip width was set to 50 mm, and the pulling speed was set to 200 mm / min. The "hydrolysis promotion treatment (jungle test)" was carried out under conditions of 70°C and 95% humidity. Specifically, the hair tie 100 was left under these conditions for one week, and tests 1 to 10 were conducted to measure the "tensile strength" and "elongation" before and after leaving the hair tie. The "jungle test" is a test method in which a sample is left in an artificially conditioned space with high temperature and humidity to simulate aging. In this case, a one-week jungle test is said to replicate normal usage conditions for approximately one year.

[0070] [Table 1]

[0071] The above tests revealed the following facts: (1) Tensile strength <Product 1: Product name "Meriya" (Tests 1 and 2)> Product 1 is the hair tie 100 according to the present embodiment, which uses organic cotton for the sheath yarn. As shown in Table 1, the "tensile strength" was 205.0 N before the jungle test (Test 1) and 189.0 N after the jungle test (Test 2), demonstrating that there was almost no change in tensile strength before and after the jungle test.

[0072] <Product 2: Product Name "Joker" (Tests 3 and 4)> Product 2 is the hair tie 100 according to the present embodiment, which uses rayon for the sheath yarn. As shown in Table 1, the "tensile strength" was 122.0 N before the jungle test (Test 3) and 116.5 N after the jungle test (Test 4), demonstrating that there was almost no change in tensile strength before and after the jungle test.

[0073] <Comparative Products 1-5 (Tests 5-10)> Comparative Products 1-5 are all hair ties currently on the market and correspond to the conventional products in the "Background Art" section of this patent specification. That is, they are "hair ties made of a string-like core material made of synthetic or natural rubber, wrapped in a nylon or polyester cloth material in a circular shape, with both ends adhesively fixed."

[0074] "Comparative Product 1 (trade name "NADOA")" (Tests 5 and 6) For Comparative Product 1, the tensile strength before the jungle test (Test 5) was 99.0 N, which is much lower than that of Example Product 1 and Example Product 2. After the jungle test, the tensile strength was 87.5 N, which is significantly lower than that of Example Products 1 and 2.

[0075] "Comparative Product 2 (trade name "Annieu")" (Test 7) ​​Comparative Product 2 has a core made of natural rubber and is surrounded by organic cotton. As shown in Table 1, the "tensile strength" after the jungle test (Test 7) ​​was 58.5 N, which is significantly lower than the tensile strength values ​​of Example Product 1 and Example Product 2.

[0076] "Comparative Product 3 (Ring Hair Tie)" (Test 8) Comparative Product 3 has a core made of natural rubber and is surrounded by a polyester coating. As shown in Table 1, the "tensile strength" of the untreated jungle test (Test 8) was 50.5 N, which is significantly lower than the tensile strength values ​​of Example Products 1 and 2.

[0077] "Comparative Product 4 (Ring Hair Tie)" (Test 9) Comparative Product 4 has a core made of synthetic rubber and is covered with polyester. After the jungle test, the tensile strength was 61.0 N, which is significantly lower than the tensile strength values ​​of Products 1 and 2.

[0078] "Comparative Product 5 (Ring Hair Tie)" (Test 10) Comparative Product 5 has a core made of natural rubber and is covered with nylon. After the jungle test (Test 10), the strength was 99.5N, which is much lower than that of Example Product 1 and also lower than that of Example Product 2.

[0079] (2) Elongation Rate Regarding "elongation rate," the elongation rate for Example 1 (product name "Meriya") was 550.3% before the jungle test and 566.2% after the jungle test, and the elongation rate for Example 2 (product name "Joker") was 548.3% and 564.8% after the jungle test, indicating that there was almost no change in elongation rate before and after the jungle test. Therefore, by conducting this test, it was found that the hair tie 100 according to the present embodiment has a much greater tensile strength than conventional hair ties, and that the tensile strength and elongation rate do not change significantly before and after the jungle test. As a result, this test proves the superiority of the hair tie 100 according to the present embodiment over conventional hair ties.

[0080] [Other embodiments] As shown in Figure 8, a substrate 30 of another form can be produced by similar plain knitting using basically the same steps as in the above-described embodiment, using the same flat knitting machine 19. Unlike the substrate 18 according to the above-described embodiment, the substrate 30 is formed in an elongated rectangular shape that is generally long in plan view.

[0081] This substrate 30 is made up of a substrate body 31 and an end portion 32 formed at one longitudinal end portion of the substrate body 31. The substrate body 31 is knitted flat by plain knitting on a flat knitting machine 19 and has a rectangular shape in a plan view. When knitting this substrate 30, as in the case of the above embodiment, it can be created by appropriately setting the "number of knitting needles" and the "height dimension (length dimension) of the knitted product" at the design stage using CAD software for product design, and in the case of this embodiment, the set value of the "height dimension" is a larger value than in the case of the above embodiment.

[0082] As shown in Figure 8, when the substrate 30 according to this embodiment is produced using a flat knitting machine 19, the covering yarn production step S1, substrate production step S2, and heat treatment step S4a are the same as those in the above embodiment, but a cutting step S3a is required before the heat treatment step S4a. In the cutting step S3, the substrate body 31 is cut to an appropriate width by an appropriate means along the width direction to produce a cut substrate having the same shape as the substrate 18 according to the above embodiment, and then the cut substrate is manually stretched into a ring shape using the same method as the substrate 18 according to the above embodiment, and in this state is subjected to a heat treatment using a steam iron in the same manner as above to shrink it, thereby producing the hair tie 100 shown in Figure 5.

[0083] In this case, as in the case of the above embodiment, since the base material body 31 is knitted using the "jersey knit" method, curled portions are formed at both ends of the width of the cut base material when it is cut in the width direction. These curled portions are used to process the ends, and after heat treatment, the hair tie is turned over to create the hair tie, just like in the above embodiment.

[0084] In the manufacturing method according to the above embodiment, the substrates 18 are produced individually, but in the manufacturing method of the hair tie according to the present embodiment, substrates 30 of a predetermined length can be produced, so a large number of cut substrates can be produced in the cutting step S3a, which is advantageous for mass-producing hair ties. The substrate 30 according to the present embodiment can be produced not only by a flat knitting machine, but also by a circular knitting machine. Circular knitting machines are used to produce, for example, socks, gloves, knitted ties, T-shirts, polo shirts, etc. Meanwhile, as described above, flat knitting machines can knit knit products that require complex knitting structures, as well as fashionable sweaters, etc.

[0085] As mentioned above, circular knitting machines are knitting machines that perform "circular knitting" within the concept of "weft knitting," and in comparison with flat knitting machines, they are unable to knit items with complex knitting structures or knit products with small stitches. However, while flat knitting machines knit with a single knitting yarn in a reciprocating motion, circular knitting machines are configured to knit around 100 knitting yarns in a rotary motion, making them more advantageous than flat knitting machines in terms of production volume.

[0086] Furthermore, after the heat treatment steps S3 and S4a in the above-described embodiment, a coloring step using a natural dye can be performed to color the hair tie 100 produced by the heat treatment steps S3 and S4a in an appropriate color. This coloring step may be performed by coloring the core yarn and sheath yarn before the heat treatment steps S3 and S4a, or may be performed at any stage in the manufacturing process.

[0087] "Dyes of natural origin" refers to dyes extracted from various animals or plants that exist in nature, and examples include carotenoids (yellow to orange) extracted from carrots and gardenias, flavonoids (yellow to brown, red to blue, red to purple) extracted from scutellaria, bayberry, red cabbage, and safflower, quinones (purple, red) extracted from safflower root, madder, and cochineal, polyphenols (brown to black) extracted from Chinese gallnut and areca nut, and indole (purple to blue) extracted from indigo and shellfish purple.

[0088] Therefore, when the hair tie 100 according to the present embodiment is colored with such dyes, unlike ordinary synthetic (chemical) dyes, the dyes themselves are naturally recyclable and do not impair the complete biorecyclability of the hair tie 100 according to the present embodiment. Even when colored, it is possible to provide a sustainable hair tie that is friendly to the human body and the environment and has 100% biorecyclability. The covering yarn production process and flat knitting machine model described in the above embodiment are merely examples and are not limited to the present embodiment. Appropriate modifications are possible within the scope of the invention according to the claims.

[0089] INDUSTRIAL APPLICABILITY The present invention relates to a method for manufacturing a hair tie and a hair tie, and therefore has wide industrial applicability. Explanation of symbols

[0090] DESCRIPTION OF SYMBOLS 10 Covering yarn 10a Covering yarn roll 11 Core yarn 11a Core yarn roll 12 Sheath yarn 12a Sheath yarn roll 13 Pre-draft roller 14 Rotating shaft 15 Rotating shaft 16 Hollow spindle 17 Weft yarn 18 Substrate 19 Flat knitting machine 20 Knitting section 21 Yarn carrier section 22 Yarn holding section 23 Touch panel type operation section 24 Discharge hole section 25 Curling section 26 Back side 27 Front side 30 Substrate 31 Substrate body 32 End 100 Hair tie S1 Covering yarn preparation process S2 Substrate preparation process S3 Heat treatment process S3a Cutting process S4a Heat treatment process

Claims

1. A hair tie that is produced by shrinking a base material made by weft knitting with covering yarn through heat treatment.

2. The hair tie according to claim 1, wherein the covering yarn is composed of a core yarn that is both biodegradable and stretchable, and a sheath yarn that is biodegradable and covers the core yarn.

3. The hair tie according to claim 2, wherein the core thread is made of natural rubber or biodegradable polyurethane, and the sheath thread is made of cotton or rayon.

4. The hair tie according to claim 1, characterized in that the weft knitting is a plain weft knitting, and curling sections that turn up towards the back side are formed on both ends of the width of the base material.

5. The hair tie according to claim 4, which is produced by turning the base material over so that the curling portion is positioned on the inner side.

6. The hair tie according to claim 1, characterized in that the covering yarn is composed of a core yarn that is both biodegradable and stretchable, and a biodegradable sheath yarn that covers the core yarn, the weft knitting is flat knitting or circular knitting, and the base material is an elongated base material that is produced by cutting the elongated base material in the width direction to create a cut base material and then subjecting the cut base material to the heat treatment.

7. The hair tie according to claim 6, wherein the core thread is made of natural rubber or biodegradable polyurethane, and the sheath thread is made of cotton or rayon.

8. The hair tie according to claim 6, which is made by plain stitch knitting and has curling sections that turn back toward the rear side on both ends of the width of the cut base material.

9. The hair tie according to claim 8, which is produced by turning the cut base material over so that the curling portion is positioned on the inner side.

10. The hair tie according to claim 1, characterized in that it is colored with a dye of natural origin.

11. A method for manufacturing a hair tie, comprising a base material preparation step of preparing a base material by weft knitting using covering yarn, and a heat treatment step of heat treating the base material to shrink it.

12. The method for manufacturing a hair tie according to claim 11, wherein the covering yarn is made by covering a core yarn that is both biodegradable and stretchable with a sheath yarn that is also biodegradable.

13. The method for manufacturing a hair tie according to claim 12, characterized in that the core yarn is made of natural rubber or biodegradable polyurethane, and the sheath yarn is made of cotton or rayon, and is produced by flat knitting.

14. The method for manufacturing a hair tie according to claim 13, wherein the flat knitting is plain knitting, and a curling portion is formed at the end of the base material in the base material preparation step.

15. The hair tie according to claim 14, wherein the base material is turned over so that the curling portion is positioned on the inner side.

16. A method for manufacturing a hair tie as described in claim 11, characterized in that the base material is created to a size that will result in a finished product with the diameter and height dimensions, assuming the diameter and height dimensions of the finished product, after shrinkage due to heat treatment in the heat treatment process.

17. A method for manufacturing a hair tie as described in claim 13, characterized in that the hair tie is manufactured by weft knitting or circular knitting, the core yarn is made of natural rubber or biodegradable polyurethane, and the sheath yarn is made of cotton or rayon, the base material is an elongated base material, and the method further comprises a cutting step of cutting the base material to a predetermined width dimension along the width direction to produce a plurality of cut base materials, and the cut base materials are heated and shrunk through a heat treatment step.

18. The method for manufacturing a hair tie according to claim 17, wherein the flat knitting is plain knitting, and after cutting in the cutting step, curling occurs at the widthwise ends of the base material.

19. The method for manufacturing a hair tie according to claim 11, further comprising a coloring step of coloring the hair tie with a dye of natural origin.

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