Thermal bonding braid
A hot melt adhesive film bonds ultrasonic-welded segments of elastic bands, addressing the issues of dense stitching and fiber damage in existing elastic woven bands, resulting in a comfortable and durable product with improved user experience.
Patent Information
- Application Number
- CN202422242387.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-12
- Publication Date
- 2025-07-15
- Estimated Expiration
- 2034-09-12
AI Technical Summary
The stitches at the existing webbing joints are too dense, resulting in a hard and rough feel at the stitching area, which is uncomfortable when fitting on the skin, and may be scratched. The sewing machine's stitching will damage the internal spandex yarn, which will have a high defect rate, affecting the wearing experience and service life.
Ultrasonic sewing technology is used to paste the outer and inner branches of the webbing on both sides of the hot melt adhesive film, so that the connection is thinner and smoother. The hot melt adhesive film of high reduction ability is used to enhance the connection firmness and avoid damage to spandex wire.
It achieves improved comfort and firmness at the connection, improves the wearing experience and yield rate, avoids spandex wire damage, and extends service life.
Smart Images
Figure CN223102917U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of webbing, and particularly relates to a thermally bonded webbing. Background Art
[0002] With the rapid development of underwear garment technology, people's demands for wearing comfort and functionality are increasing day by day. Elastic webbing, as an essential accessory category for clothing, especially for sportswear and underwear, is very commonly used. Currently, the most widely used elastic shuttle woven webbing on the market is mainly woven and produced with polyester or nylon materials combined with elastic latex silk or spandex.
[0003] When it is necessary to connect two incisions, it is usually completed by an overlock sewing machine. Sewing requires 4 - 6 sewing threads to sew at high speed simultaneously to improve the strength of the interface part. For the webbing of the prior art, due to the overly dense stitch at the connection, the sewn part feels stiff and rough, and there will be discomfort caused by friction when it touches the skin, and even abrasions or sports injuries may occur during human movement. Using a sewing machine to sew will also damage and break the spandex filaments inside the elastic webbing, resulting in a high defective rate. During the wearing process, the spandex filaments will run to the surface of the webbing, with poor quality, shortened service life and affecting the wearing experience.
[0004] Therefore, it is necessary to provide a thermally bonded webbing to solve the above technical problems. Summary of the Utility Model
[0005] The utility model provides a thermally bonded webbing, which can still feel comfortable when touching the skin, improves the wearing experience, and has a firm connection.
[0006] The technical solution of the utility model is as follows:
[0007] A thermally bonded webbing, the thermally bonded webbing is annular, and it includes a first main body band and a first hot melt adhesive film. The first main body band includes a first band body, a first outer branch, a first inner branch, a second outer branch and a second inner branch. One ends of the first outer branch and the first inner branch are integrally woven and formed with one end of the first band body, and one ends of the second inner branch and the second outer branch are integrally woven and formed with the other end of the first band body. The other end of the first outer branch is ultrasonically sewn and connected to the other end of the second outer branch, and the other end of the first inner branch is ultrasonically sewn and connected to the other end of the second inner branch. The outer surface of the first hot melt adhesive film is bonded to the first outer branch and the second outer branch, and the inner surface of the first hot melt adhesive film is bonded to the first inner branch and the second inner branch, and the first outer branch and the second inner branch have an overlapping part.
[0008] In the heat-bonding webbing of the present utility model, the length of the first hot-melt adhesive film is equal to the sum of the lengths of the first outer branch and the second outer branch, and is also equal to the sum of the lengths of the first inner branch and the second inner branch.
[0009] In the heat-bonding webbing of the present utility model, the lengths of both the first inner branch and the second outer branch are 18 mm - 22 mm.
[0010] In the heat-bonding webbing of the present utility model, the lengths of both the first inner branch and the second outer branch are 20 mm.
[0011] In the heat-bonding webbing of the present utility model, the first hot-melt adhesive film is made of TPU material with high reduction ability.
[0012] Another technical solution of the present utility model is as follows:
[0013] A heat-bonding webbing, the heat-bonding webbing is strip-shaped, and it includes a plurality of second main belts and a plurality of second hot-melt adhesive films. The plurality of second main belts are arranged along the length direction of the heat-bonding webbing, and the length direction of the second main belt is consistent with the length direction of the heat-bonding webbing. The second main belt includes a second belt body, a first upper branch, a first lower branch, a second upper branch, and a second lower branch. One ends of the first upper branch and the first lower branch are integrally woven and formed with one end of the second belt body, and one ends of the second lower branch and the second upper branch are integrally woven and formed with the other end of the second belt body. The other end of the first upper branch is ultrasonically stitched and connected to the other end of the second upper branch of the adjacent second main belt, and the other end of the first lower branch is ultrasonically stitched and connected to the other end of the second lower branch of the adjacent second main belt. The upper surface of the second hot-melt adhesive film is bonded to the first upper branch and the second upper branch of the adjacent second main belt, and the lower surface of the second hot-melt adhesive film is bonded to the first lower branch and the second lower branch of the adjacent second main belt, and there is an overlapping part between the first lower branch and the second upper branch of the adjacent second main belt.
[0014] In the heat-bonding webbing of the present utility model, the length of the second hot-melt adhesive film is equal to the sum of the lengths of the first upper branch and the second upper branch of the adjacent second main belt, and is also equal to the sum of the lengths of the first lower branch and the second lower branch of the adjacent second main belt.
[0015] In the heat-bonding webbing of the present utility model, the lengths of both the first upper branch and the second lower branch are 18 mm - 22 mm.
[0016] In the heat-bonding webbing of the present utility model, the lengths of both the first upper branch and the second lower branch are 20 mm.
[0017] In the heat-bonded webbing of the present utility model, the second hot melt adhesive film is made of TPU material with high reduction ability.
[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows:
[0019] For the heat-bonded webbing of the present utility model, the first outer branch and the second outer branch sewn by ultrasonic waves, and the first inner branch and the second inner branch sewn by ultrasonic waves are respectively pasted on both sides of the first hot melt adhesive film, so that both ends of the first main belt can be connected to form a ring. The connection part is thinner and smoother, and it is still comfortable to wear close to the skin. The first outer branch and the second outer branch have an overlapping part, which can make the contact area between the two and the first hot melt adhesive film larger and the connection firm. The heat-bonded webbing of the present utility model is still comfortable to wear close to the skin, improving the wearing experience, and the connection is firm. During the processing, the spandex filaments inside the first main belt will not be damaged, improving the yield rate.
[0020] For the heat-bonded webbing of the present utility model, the first lower branch and the second lower branch sewn by ultrasonic waves, and the first upper branch and the second upper branch sewn by ultrasonic waves are respectively pasted on both sides of the second hot melt adhesive film, so that one end of two adjacent second main belts can be connected to form a strip. The connection part is thinner and smoother, and it is still comfortable to wear close to the skin. The first lower branch and the second lower branch have an overlapping part, which can make the contact area between the two and the second hot melt adhesive film larger and the connection firm. The heat-bonded webbing of the present utility model is still comfortable to wear close to the skin, improving the wearing experience, and the connection is firm. During the processing, the spandex filaments inside the second main belt will not be damaged, improving the yield rate. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following briefly introduces the drawings required to be used in the embodiments. The drawings in the following description are only the corresponding drawings of some embodiments of the present utility model.
[0022] Figure 1 It is a schematic structural diagram of the heat-bonded webbing provided by the first preferred embodiment of the present utility model.
[0023] Figure 2 It is a schematic structural diagram of the heat-bonded webbing provided by the second preferred embodiment of the present utility model.
[0024] Among them, Figure 1 the identifications are as follows:
[0025] 11. First main belt,
[0026] 111. First belt body, 112. First outer branch, 113. First inner branch, 114. Second outer branch, 115. Second inner branch,
[0027] 12. The first hot melt adhesive film.
[0028] Figure 2 The identification is as follows:
[0029] 21. The second main body belt,
[0030] 211. The second belt body, 212. The first upper branch, 213. The first lower branch, 214. The second upper branch, 215. The second lower branch,
[0031] 22. The second hot melt adhesive film.
[0032] In the figure, units with similar structures are denoted by the same reference numerals. Detailed implementation manners
[0033] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present utility model.
[0034] The directional terms mentioned in the present utility model, such as "upper", "lower", "front", "rear", "left", "right", "inner", "outer", "side", "top" and "bottom", etc., are only references to the orientation of the accompanying drawings. The directional terms used are for explaining and understanding the present utility model, rather than for limiting the present utility model.
[0035] The terms "first", "second", etc. in the terms of the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying relative importance, nor as a limitation on the sequence.
[0036] In the present utility model, unless otherwise clearly defined and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.
[0037] In the prior art, due to the overly dense stitch at the connection, the feel of the stitched part is stiff and rough. When it touches the skin, there will be discomfort caused by friction, and even abrasions or sports injuries may occur during human movement. Using a sewing machine to sew will also damage and break the spandex filaments inside the elastic webbing, resulting in a high defective rate. During the wearing process, the spandex filaments will run to the surface of the webbing, with poor quality, shortened service life and affected wearing experience.
[0038] The following is a preferred embodiment of a heat-bonded webbing provided by the present invention that can solve the above technical problems.
[0039] Please refer to Figure 1 , a first preferred embodiment of the present invention provides a heat-bonded webbing. The heat-bonded webbing is annular and includes a first main body band 11 and a first hot melt adhesive film 12. The first main body band 11 includes a first band body 111, a first outer branch 112, a first inner branch 113, a second outer branch 114 and a second inner branch 115. One ends of the first outer branch 112 and the first inner branch 113 are integrally woven and formed with one end of the first band body 111, and one ends of the second inner branch 115 and the second outer branch 114 are integrally woven and formed with the other end of the first band body 111. The other end of the first outer branch 112 is ultrasonically stitched and connected to the other end of the second outer branch 114, and the other end of the first inner branch 113 is ultrasonically stitched and connected to the other end of the second inner branch 115. The outer surface of the first hot melt adhesive film 12 is bonded to the first outer branch 112 and the second outer branch 114, and the inner surface of the first hot melt adhesive film 12 is bonded to the first inner branch 113 and the second inner branch 115, and the first outer branch 112 and the second inner branch 115 have an overlapping part, that is, the length of the first outer branch 112 is greater than the length of the second outer branch 114, and the length of the second inner branch 115 is greater than the length of the first inner branch 113.
[0040] For the heat-bonded webbing of the present invention, the ultrasonically stitched first outer branch 112 and second outer branch 114, and the ultrasonically stitched first inner branch 113 and second inner branch 115 are respectively pasted on both sides of the first hot melt adhesive film 12, so that the two ends of the first main body band 11 can be connected to form an annular shape. The connection part is thinner and smoother, and it still feels comfortable when touching the skin. The first outer branch 112 and the second outer branch 114 have an overlapping part, which can make the contact area between the two and the first hot melt adhesive film 12 larger and the connection firm. The heat-bonded webbing of the present invention still feels comfortable when touching the skin, improves the wearing experience, and has a firm connection. During the processing, it will not damage the spandex filaments inside the first main body band 11, and improves the qualified rate.
[0041] Please continue to refer to Figure 1, the length of the first hot melt adhesive film 12 is equal to the sum of the lengths of the first outer branch 112 and the second outer branch 114, as well as the sum of the lengths of the first inner branch 113 and the second inner branch 115. With this structure, the first outer branch 112 and the second outer branch 114, and the first inner branch 113 and the second inner branch 115 can be completely bonded to the first hot melt adhesive film 12, making the connection at both ends of the first main body band 11 more firm.
[0042] Please continue to refer to Figure 1 , the length d1 of the first outer branch 112 and the length d2 of the second inner branch 115 are both 18 mm - 22 mm. In the above structure, the lengths of the first outer branch 112 and the second inner branch 115 are both 18 mm - 22 mm, which is the minimum size to meet the requirements of ultrasonic sewing. When the perimeter of the heat-bonded webbing is fixed, the sum of the lengths of the first inner branch 113 and the second inner branch 115 is fixed, and the sum of the lengths of the first outer branch 112 and the second outer branch 114 is fixed, and the lengths of the first outer branch 112 and the second inner branch 115 are the minimum size to meet the requirements of ultrasonic sewing, the lengths of the first inner branch 113 and the second outer branch 114 can be longer, making the connection of the first main body band 11 more firm.
[0043] Please continue to refer to Figure 1 , the length d1 of the first outer branch 112 and the length d2 of the second inner branch 115 are both 20 mm. With this structure, not only can the lengths of the first inner branch 113 and the second outer branch 114 be longer, but also it is convenient to perform ultrasonic sewing on the first inner branch 113 and the second inner branch 115, and the first outer branch 112 and the second outer branch 114.
[0044] Please continue to refer to Figure 1 , the first hot melt adhesive film 12 is made of TPU material with high reduction ability. With this structure, there is still good elasticity at the connection of both ends of the first main body band 11, improving the usage experience of the whole heat-bonded webbing.
[0045] The processing process of the heat-bonded webbing of the first preferred embodiment of the present utility model.
[0046] During processing, first, the raw materials of the first outer branch 112 and those of its second outer branch 114 are ultrasonically stitched together, and at the same time, the redundant parts of both are cut off to form the first outer branch 112 and the second outer branch 114, with their ends joined. Then, the release paper outside the first hot melt adhesive film 12 is torn off and pasted on the first outer branch 112 and the second outer branch 114 and pre-fixed at a temperature of 95°C - 100°C. Next, the raw materials of the first inner branch 113 and those of the second inner branch 115 are ultrasonically stitched together, and at the same time, the redundant parts of both are cut off to form the first inner branch 113 and the second inner branch 115, with their ends joined. Finally, the release paper on the inner surface of the first hot melt adhesive film 12 is torn off, and the first inner branch 113 and the second inner branch 115 are pasted on the inner surface of the first hot melt adhesive film 12 and hot-pressed for fixation. When the hot-pressing method is flat pressing, the temperature is 130°C - 165°C, the hot-pressing time is 20 - 30 seconds, and the pressure is 40 - 60 psi. When the hot-pressing method is continuous bonding, the temperature is 150°C - 200°C, the pressure is 29.0 psi, and the speed is 1.0 - 1.5 m / min.
[0047] This is the processing process of the heat-bonded webbing of the first preferred embodiment of the present utility model.
[0048] For the heat-bonded webbing of the present utility model, the first outer branch and the second outer branch stitched by ultrasonic waves, and the first inner branch and the second inner branch stitched by ultrasonic waves are respectively pasted on both sides of the first hot melt adhesive film, so that the two ends of the first main belt can be connected to form a ring. The connection part is thinner and smoother, and it is still comfortable to wear against the skin. The first outer branch and the second outer branch have an overlapping part, which can make the contact area between the two and the first hot melt adhesive film larger and the connection firm. The heat-bonded webbing of the present utility model is still comfortable to wear against the skin, improving the wearing experience, and the connection is firm. Also, the spandex filaments inside the first main belt will not be damaged during the processing, improving the yield rate.
[0049] Please refer to Figure 2, the second preferred embodiment of the present utility model provides a heat-bonded webbing. The heat-bonded webbing is strip-shaped and includes a plurality of second main bands 21 and a plurality of second hot-melt adhesive films 22. The plurality of second main bands 21 are arranged along the length direction of the heat-bonded webbing. The length direction of the second main band 21 is consistent with the length direction of the heat-bonded webbing. The second main band 21 includes a second band body 211, a first upper branch 212, a first lower branch 213, a second upper branch 214, and a second lower branch 215. One end of both the first upper branch 212 and the first lower branch 213 is integrally woven with one end of the second band body 211. One end of both the second lower branch 215 and the second upper branch 214 is integrally woven with the other end of the second band body 211. The other end of the first upper branch 212 is ultrasonically stitched and connected to the other end of the second upper branch 214 of the adjacent second main band 21. The other end of the first lower branch 213 is ultrasonically stitched and connected to the other end of the second lower branch 215 of the adjacent second main band 21. The upper surface of the second hot-melt adhesive film 22 is bonded to the first upper branch 212 and the second upper branch 214 of the adjacent second main band 21. The lower surface of the second hot-melt adhesive film 22 is bonded to the first lower branch 213 and the second lower branch 215 of the adjacent second main band 21. And the first lower branch 213 and the second upper branch 214 of the adjacent second main band 21 have an overlapping part, that is, the length of the first lower branch 213 is greater than the length of the second lower branch 215 of the adjacent second main band 21, and the length of the second upper branch 214 is greater than the length of the first upper branch 212 of the adjacent second main band 21.
[0050] For the heat-bonded webbing of the present utility model, the ultrasonically stitched first lower branch 213 and second lower branch 215, and the ultrasonically stitched first upper branch 212 and second upper branch 214 are respectively pasted on both sides of the second hot-melt adhesive film 22, so that one end of two adjacent second main bands 21 can be connected, thus forming a strip shape. The connection part is thinner and smoother, and it is still comfortable to wear against the skin. The first lower branch 213 and the second upper branch 214 have an overlapping part, which can make the contact area between the two and the second hot-melt adhesive film 22 larger and the connection firm. For the heat-bonded webbing of the present utility model, it is still comfortable to wear against the skin, improving the wearing experience, and the connection is firm. During the processing, the spandex filaments inside the second main band 21 will not be damaged, improving the yield rate.
[0051] Please continue to refer to Figure 2 , the length of the second hot-melt adhesive film 22 is equal to the sum of the lengths of the first upper branch 212 and the second upper branch 214 of the adjacent second main band 21, and is also equal to the sum of the lengths of the first lower branch 213 and the second lower branch 215 of the adjacent second main band 21. Adopting this structure can make the first lower branch 213 and the second lower branch 215, and the first upper branch 212 and the second upper branch 214 completely bonded to the second hot-melt adhesive film 22, making the connection between one end of two adjacent second main bands 21 more firm.
[0052] Please continue to refer to Figure 2 wherein the length L1 of the first upper branch 212 and the length L2 of the second lower branch 215 are both 18 mm - 22 mm. When the perimeter of the heat-bonded webbing is fixed, the sum of the lengths of the first upper branch 212 and the second upper branch 214 is fixed, and the sum of the lengths of the first lower branch 213 and the second lower branch 215 is fixed, the lengths of the first upper branch 212 and the second upper branch 214 are the minimum sizes that meet the requirements of ultrasonic sewing. Then, the lengths of the first lower branch 213 and the second upper branch 214 can be longer, making the connection between two adjacent second main belts 21 more secure.
[0053] Please continue to refer to Figure 2 wherein the length L1 of the first upper branch 212 and the length L2 of the second lower branch 215 are both 20 mm. With this structure, not only can the lengths of the first lower branch 213 and the second upper branch 214 be longer, but also it is convenient to perform ultrasonic sewing on the first upper branch 212 and the second upper branch 214, and the first lower branch 213 and the second lower branch 215.
[0054] Please continue to refer to Figure 2 wherein the second hot melt adhesive film 22 is made of TPU material with high reduction ability. With this structure, there is still good elasticity at the connection between two adjacent second main belts 21, improving the usage experience of the whole heat-bonded webbing.
[0055] For the heat-bonded webbing of the present utility model, the first lower branch and the second lower branch sewn by ultrasonic, and the first upper branch and the second upper branch sewn by ultrasonic are respectively pasted on two sides of the second hot melt adhesive film, so that one end of two adjacent second main belts can be connected to form a strip. The connection part is thinner and smoother, and it still feels comfortable when contacting the skin. The first lower branch and the second lower branch have an overlapping part, which can make the contact area between the two and the second hot melt adhesive film larger and the connection more secure. The heat-bonded webbing of the present utility model still feels comfortable when contacting the skin, improving the wearing experience, and the connection is secure. During the processing, the spandex filaments inside the second main belt will not be damaged, improving the yield rate.
[0056] For the heat-bonded webbing of the present utility model, the first lower branch and the second lower branch sewn by ultrasonic, and the first upper branch and the second upper branch sewn by ultrasonic are respectively pasted on two sides of the second hot melt adhesive film, so that one end of two adjacent second main belts can be connected to form a strip. The connection part is thinner and smoother, and it still feels comfortable when contacting the skin. The first lower branch and the second lower branch have an overlapping part, which can make the contact area between the two and the second hot melt adhesive film larger and the connection more secure. The heat-bonded webbing of the present utility model still feels comfortable when contacting the skin, improving the wearing experience, and the connection is secure. During the processing, the spandex filaments inside the second main belt will not be damaged, improving the yield rate.
[0057] In summary, although the present utility model has been disclosed above with preferred embodiments, the protection scope of the present utility model is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present utility model, according to the concept of the technical solution of the present utility model, makes equivalent substitutions or changes, and should be covered within the protection scope of the present utility model.
Claims
1. A heat-bonded webbing, characterized in that, The heat-bonded webbing is annular and includes a first main body band and a first hot melt adhesive film. The first main body band includes a first band body, a first outer branch, a first inner branch, a second outer branch, and a second inner branch. One ends of the first outer branch and the first inner branch are integrally woven and formed with one end of the first band body. One ends of the second inner branch and the second outer branch are integrally woven and formed with the other end of the first band body. The other end of the first outer branch is ultrasonically stitched and connected to the other end of the second outer branch. The other end of the first inner branch is ultrasonically stitched and connected to the other end of the second inner branch. The outer surface of the first hot melt adhesive film is bonded to the first outer branch and the second outer branch. The inner surface of the first hot melt adhesive film is bonded to the first inner branch and the second inner branch, and the first outer branch and the second inner branch have an overlapping portion.
2. The heat-bonded webbing according to claim 1, wherein The length of the first hot melt adhesive film is equal to the sum of the lengths of the first outer branch and the second outer branch, and is also equal to the sum of the lengths of the first inner branch and the second inner branch.
3. The heat-bonded webbing according to claim 2, wherein The lengths of both the first outer branch and the second inner branch are 18 mm - 22 mm.
4. The heat-bonding webbing according to claim 3, wherein The lengths of both the first outer branch and the second inner branch are 20 mm.
5. The heat-bonded webbing according to claim 1, wherein, The first hot melt adhesive film is made of TPU material with high reduction ability.
6. A heat-bonded webbing, characterized in that, The heat-bonded webbing is strip-shaped and includes a plurality of second main body bands and a plurality of second hot melt adhesive films. The plurality of second main body bands are arranged along the length direction of the heat-bonded webbing. The length direction of the second main body band is the same as the length direction of the heat-bonded webbing. The second main body band includes a second band body, a first upper branch, a first lower branch, a second upper branch, and a second lower branch. One ends of the first upper branch and the first lower branch are integrally woven and formed with one end of the second band body. One ends of the second lower branch and the second upper branch are integrally woven and formed with the other end of the second band body. The other end of the first upper branch is ultrasonically stitched and connected to the other end of the second upper branch of the adjacent second main body band. The other end of the first lower branch is ultrasonically stitched and connected to the other end of the second lower branch of the adjacent second main body band. The upper surface of the second hot melt adhesive film is bonded to the first upper branch and the second upper branch of the adjacent second main body band. The lower surface of the second hot melt adhesive film is bonded to the first lower branch and the second lower branch of the adjacent second main body band, and the first lower branch and the second upper branch of the adjacent second main body band have an overlapping portion.
7. The heat-bonded webbing according to claim 6, wherein, The length of the second hot melt adhesive film is equal to the sum of the lengths of the first upper branch and the second upper branch of the adjacent second main body band, and is also equal to the sum of the lengths of the first lower branch and the second lower branch of the adjacent second main body band.
8. The heat-bonded webbing according to claim 7, wherein The lengths of both the first upper branch and the second lower branch are 18 mm - 22 mm.
9. The heat-bonded webbing according to claim 8, wherein, The lengths of both the first upper branch and the second lower branch are 20 mm.
10. The heat-bonded webbing according to claim 6, wherein, The second hot melt adhesive film is made of TPU material with high reduction ability.