Copper wire sewing thread ultra-high frequency antenna and manufacturing method

Abstract

The present invention discloses a copper wire sewing line UHF antenna material and a method for making an UHF antenna with a sewing machine in the field of UHF radio frequency antenna technology. The copper wire sewing line UHF antenna includes a copper wire sewing line, which is formed by twisting bare copper wire and sewing line. The copper wire sewing line is sewn on a label cloth substrate to form a copper wire sewing line UHF antenna; the manufacturing method includes twisting the copper wire sewing line, determining the sewing type, determining the stitch track, stitch pitch, and sewing length of the sewing, and sewing copper on the label cloth substrate. The copper wire sewing line UHF antenna of the present invention has good electrical conductivity, small diameter, large tensile strength, and good softness. The high-speed sewing machine sews the UHF antenna on the cloth material, which has the advantages of water resistance, folding resistance, ironing resistance, and high manufacturing efficiency. The manufacturing cost is low, which is conducive to promoting the wide application of radio frequency technology in the footwear, clothing, and handbag industries, and improving the level of information management.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-high frequency antennas, in particular to a copper wire sewing thread ultra-high frequency antenna material and a method for manufacturing an ultra-high frequency antenna using a sewing machine. Background Art

[0002] The market for ultra-high frequency (UHF) tags in the footwear and apparel industry is booming, with global annual usage approaching 10 billion units. The mainstream RFID tags used in the industry are paper labels and hangtags, with a smaller number of washable RFID tags. However, all RFID tags have numerous drawbacks.

[0003] 1. Current application and shortcomings of ultra-high frequency paper labels and tags in the footwear and apparel industry

[0004] A: Paper labels and hang tags are not suitable for washing products in the footwear and apparel industry. They can only be used in warehousing, logistics, and sales. Consumers will immediately throw away the radio frequency paper labels after purchasing the shoes and apparel. Moreover, paper labels and hang tags cannot be used in the washing process of shoes and apparel. Therefore, they cannot provide product information tracking and tracing for the footwear and apparel industry. The footwear and apparel industry has not achieved full product tracking services.

[0005] B: UHF paper labels have a four-layer structure: a face paper layer, an inlay layer, a pressure-sensitive adhesive layer, and a release paper layer. Due to the high manufacturing cost, they are currently only affordable to large apparel companies. Many footwear and apparel companies, considering the cost, have not adopted UHF labels or hangtags on their products, failing to manage information related to each item.

[0006] C: The need to reduce the cost of UHF paper labels: The chip, paper, and glue of UHF paper labels are the basic costs that cannot be changed by label manufacturers. The only material and process that can be improved are the materials and processes of UHF antennas. Traditional PET aluminum foil composite films undergo multiple processes such as optical plate making, chemical etching, and water washing. This is not only costly but also produces a large amount of waste liquid and wastewater, polluting the environment. An innovative UHF antenna material and antenna manufacturing process are urgently needed.

[0007] D: The way the UHF antenna is mounted on the tag substrate determines the RFID tag's practicality in specific scenarios. For the footwear and apparel industry, UHF tags must be washable and ironable, requiring the label substrate to be replaced with heat-resistant cloth instead of paper. The traditional inlay process, which uses a pressure-sensitive adhesive layer attached to paper, is not suitable for washing and ironing scenarios. Therefore, an innovative method for mounting the UHF antenna on the fabric tag substrate is urgently needed.

[0008] 2. Application status and defects of washable UHF cloth laundry labels

[0009] Unlike paper RFID tags, the UHF antenna in washable cloth laundry tags is made of multiple strands of carbon fiber. Because the diameter of the carbon fiber antenna material is larger than 0.5 mm, it can only be formed using a coiling process on the label cloth substrate to create a near-sinusoidal UHF antenna, which is then secured to the label cloth with sewing thread. Therefore, it must be washable, foldable, pressure-resistant, and durable, as well as durable to washing and ironing. However, the high cost of carbon fiber and the complex process of coiling the antenna into a near-sinusoidal antenna contribute to the high price of laundry tags, hindering their widespread application.

[0010] Therefore, there is an urgent need for conductive fiber materials that can replace carbon fiber, processes for making ultra-high frequency antennas, and solutions for the connection process between conductive fiber antennas and label cloth substrates. Summary of the Invention

[0011] In order to overcome the deficiencies of the existing technology, the present invention provides a copper wire sewing thread ultra-high frequency antenna and a manufacturing method thereof.

[0012] The technical solutions of the present invention are as follows:

[0013] A copper wire sewing thread ultra-high frequency antenna comprises a copper wire sewing thread, which is formed by twisting bare copper wire and sewing thread; the copper wire sewing thread is sewn on a label cloth substrate to form the copper wire sewing thread ultra-high frequency antenna.

[0014] Bare copper wire has a diameter of 0.06 mm to 0.07 mm. Annealed copper wire with a diameter of 0.06 mm is known for its flexibility. Sewing thread has a diameter of 0.12 mm. Copper sewing thread has a diameter of less than 0.2 mm. The twist of bare copper wire and sewing thread combined is greater than 400, ensuring a smooth and unbroken sewing process.

[0015] The resistance of the copper wire sewing thread per meter is less than 7.5 ohms, the resistance of the entire copper wire sewing thread UHF antenna is less than 2.5 ohms, and the tensile strength is greater than 10N.

[0016] The copper wire sewing thread can be sewn synchronously with the sewing bottom thread on the label cloth substrate, so that one side surface of the label cloth substrate has a sewing track of the copper wire sewing thread: if a straight sewing track is selected, the length of the sewing track of the copper wire sewing thread is 100 mm to 120 mm; if a zigzag or square wave sewing track is selected, the length of the sewing track of the copper wire sewing thread is 60 mm to 90 mm.

[0017] The copper wire sewing thread can also be sewn separately on the label cloth substrate, so that the upper and lower surfaces of the label cloth substrate have sewing tracks of the copper wire sewing thread: the length of the sewing track of the copper wire sewing thread with a straight sewing track is 80 mm to 90 mm.

[0018] A method for making a copper wire sewing thread ultra-high frequency antenna comprises the following steps: (1) selecting bare copper wire and sewing thread, twisting them together to form a copper wire sewing thread; (2) determining whether to use the copper wire sewing thread alone to sew the ultra-high frequency antenna, or to use the copper wire sewing thread and sewing bobbin thread together to sew the ultra-high frequency antenna; (3) determining the stitch trajectory (straight line, zigzag, wavy, sinusoidal, combined, etc.), stitch pitch, and sewing length; and (4) sewing the copper wire sewing thread on a label cloth substrate to form an ultra-high frequency antenna.

[0019] After sewing is completed, the steps also include determining the standard specifications for the UHF antenna manufacturing process: sewing UHF antennas with different parameters separately and performing sensitivity measurements; based on the measured recognition sensitivity of the UHF antenna, changing the stitch trajectory, stitch pitch, and sewing length to obtain the sewing parameters for the best recognition sensitivity, and formulating the process standards for sewing antennas.

[0020] The present invention according to the above scheme has the beneficial effect that the copper wire sewing thread ultra-high frequency antenna of the present invention has good conductivity, small diameter, high tensile strength and good flexibility. The ultra-high frequency antenna is sewn on the cloth material with a high-speed sewing machine, and has the advantages of being washable, foldable, and ironing-resistant, and having high production efficiency. Its production cost is only 1 / 6 of the cost of traditional PET aluminum foil chemical etching antennas and 1 / 120 of the cost of existing carbon fiber antennas. It is conducive to promoting the widespread application of radio frequency technology in the footwear, clothing, linen, and handbag industries, and improving the level of information management. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1a It is a schematic diagram of a UHF antenna with a bottom copper wire sewing thread;

[0022] Figure 1b This is a schematic diagram of a UHF antenna with copper sewing thread and no bottom line;

[0023] Figure 2 A schematic diagram comparing the diameter, conductivity and sewing adaptability of various wire materials;

[0024] Figure 3a It is a schematic diagram of a zigzag copper sewing thread UHF antenna;

[0025] Figure 3b Schematic diagram of a trapezoidal copper sewing wire UHF antenna;

[0026] Figure 3c Schematic diagram of a square-wave copper sewing thread UHF antenna;

[0027] Figure 3d Schematic diagram of a UHF antenna made of copper sewing thread with a nearly sinusoidal waveform;

[0028] Figure 3eThis is a schematic diagram of a combined copper wire sewing thread UHF antenna;

[0029] Figure 4 Schematic diagram of a RFID tag with antenna wings, which is formed by coupling a copper sewing thread UHF antenna with a miniature dual-coil RF resonant cavity assembly;

[0030] Figure 5 Schematic diagram of a RFID tag with antenna wings, which is formed by coupling a copper wire sewing thread UHF antenna and a single-loop RF resonant cavity assembly.

[0031] In the drawings, the reference numerals are:

[0032] 1. Copper sewing thread; 2. Bottom sewing thread; 3. Upper label cloth; 4. Lower label cloth; 5-1. Micro dual-coil RF resonant cavity assembly; 5-2. Single-coil RF resonant cavity assembly. DETAILED DESCRIPTION

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] like Figures 1a to 5 As shown, in order to solve the defects of existing UHF radio frequency tags in the footwear industry and other industries, such as high cost and poor resistance to washing and ironing, the present invention proposes a copper wire sewing thread UHF antenna, which is sewn by copper wire sewing thread 1 on the tag cloth substrate to form a copper wire sewing thread UHF antenna.

[0035] The copper sewing thread 1 is formed by twisting bare copper wire and sewing thread. To ensure the basic performance of the copper sewing thread 1 for making ultra-high frequency antennas, the present invention uses bare copper wire with a diameter of 0.06 mm to 0.07 mm. The bare copper wire with a diameter of 0.06 mm is called annealed copper wire, which has better flexibility. The diameter of the sewing thread used in the present invention is 0.12 mm.

[0036] The label cloth substrate can be a single-layer cloth label or a double-layer cloth label (eg, an upper-layer label cloth 3 and a lower-layer label cloth 4).

[0037] During the production of the copper sewing thread 1, the twist of the bare copper wire and sewing thread is greater than 400, ensuring a smooth sewing process and preventing thread breakage. The copper sewing thread 1 has a resistance of less than 7.5 ohms per meter, and the resistance of the entire UHF antenna is less than 2.5 ohms. The copper sewing thread 1 has a diameter of less than 0.2 mm and a tensile strength greater than 10 N, meeting the basic performance requirements for making an UHF antenna.

[0038] like Figures 3a to 3eAs shown, in the present invention, the sewing trajectory of the copper wire sewing thread 1 to form the ultra-high frequency antenna can be: zigzag, trapezoidal, flat wave, approximate sine wave, and can also be a combination of the above various shapes. The specific shape can be selected according to different needs.

[0039] like Figure 1a As shown, the copper sewing thread 1 of the present invention can be sewn synchronously with the sewing bobbin thread 2 on the label fabric substrate, so that one side of the label fabric substrate has a sewing track of the copper sewing thread 1. During the sewing process, the copper sewing thread 1 located on the upper side of the label fabric substrate and the sewing bobbin thread 2 located on the lower side of the label fabric substrate are cross-wound inside the label fabric substrate. After winding, the copper sewing thread 1 and the sewing bobbin thread 2 are respectively routed forward.

[0040] Based on this routing method, the length of the sewing track of the copper wire sewing thread 1 with a straight sewing track is 100 mm to 120 mm; the length of the sewing track of the copper wire sewing thread 1 with a zigzag or square wave sewing track is 60 mm to 90 mm.

[0041] like Figure 1b As shown, the copper sewing thread 1 of the present invention can also be sewn separately onto the label fabric substrate, so that the upper and lower surfaces of the label fabric substrate have sewing tracks of the copper sewing thread 1. During the sewing process, the copper sewing thread 1 passes downward through the label fabric substrate at the current stitch position and the copper sewing thread 1 extending from the previous stitch, then winds forward, turns around to the next stitch position, and passes up at the current stitch position. After passing up, the copper sewing thread 1 runs on the upper surface to the next stitch position and passes downward, passes through the copper sewing thread 1 on the lower side of the label fabric substrate, and then winds forward.

[0042] This routing method results in a shorter sewing length than the previous embodiment, where the copper sewing thread 1 has a bobbin thread. Specifically, the copper sewing thread 1 with a straight sewing path has a length of 80 to 90 mm.

[0043] A method for manufacturing a copper wire sewing thread ultra-high frequency antenna, comprising:

[0044] S1. Select bare copper wire and sewing thread, and twist them together to form a copper wire sewing thread;

[0045] S2. Determine whether to use copper sewing thread alone to sew the UHF antenna, or to use copper sewing thread and bobbin thread together to sew the UHF antenna;

[0046] S3, determining the stitch track, stitch length, and sewing length;

[0047] S4. Sewing copper wire sewing thread on the label cloth base material to form an ultra-high frequency antenna.

[0048] After sewing is completed, the steps also include determining the standard specifications for the UHF antenna manufacturing process: first, sew UHF antennas with different parameters separately and perform sensitivity measurements; then, based on the measured recognition sensitivity of the UHF antenna, change the stitch trajectory, stitch pitch, and sewing length to obtain the sewing parameters for the best recognition sensitivity and formulate the process standards for sewing antennas.

[0049] like Figure 1a 、 Figure 1b 、 Figure 4 、 Figure 5 As shown, in the present invention, the UHF antenna made of copper sewing thread can be combined with different RF resonant cavities and RF chips to form a complete RF tag. In the specific implementation process, the UHF antenna can be coupled with the RF resonant cavity and the RF new product and then directly encapsulated between the upper label cloth and the lower label cloth 4 to form a RF tag. The RF resonant cavity can also be connected to the RF chip and then wrapped between the upper label cloth 3 and the lower label cloth 4, and then the upper label cloth 3 and the lower label cloth 4 are sewn with copper sewing thread, and the coupling of the UHF antenna and the RF resonant cavity is completed, thereby forming a RF tag.

[0050] Specifically, in Figure 4 In the embodiment, the sinusoidal UHF antenna is connected to the miniature dual-coil RF resonant cavity assembly 5-1 (including the dual-coil RF resonant cavity and the RF chip) to form an RF tag with antenna wings. Figure 5 In the figure, the sawtooth-shaped UHF antenna is coupled with the single-loop RF resonant cavity assembly 5-2 (including the single-loop RF resonant cavity and the RF chip) to form a RF tag with antenna wings.

[0051] In the process of making UHF antennas using sewing technology, the requirements for antenna materials include:

[0052] (1) Conductive properties

[0053] Meeting the electrical conductivity requirements of UHF antennas is one of the most important requirements for manufacturing UHF antenna materials. The performance of UHF antennas is evaluated by their quality factor. The quality factor of an UHF antenna is Q = 2πfL / R, where f is the frequency of the UHF signal, L is the equivalent inductance of the UHF antenna, and R is the resistance of the UHF antenna.

[0054] In practice, when the resistance of the UHF antenna is greater than 2.5 ohms, the sensitivity of the UHF antenna begins to decrease. Therefore, the resistance value of the UHF antenna is required to be less than 7.5 ohms per meter.

[0055] (2) Diameter

[0056] When sewing a UHF antenna onto a label substrate using a sewing process, the diameter of the conductive fiber or other thread must be less than 0.2mm. This must ensure that the sewing machine remains functional regardless of whether the thread is sewn with or without a bobbin thread.

[0057] (3) Tensile strength

[0058] The tensile strength of the UHF antenna material is greater than 9.5N, allowing it to remain unbroken on high-speed industrial sewing machines.

[0059] (4) Button adaptability

[0060] The smoothness of the antenna sewn on the label cloth is affected by the softness of the antenna material, requiring the softness of the conductive fiber to be similar to that of 402 / S fine sewing thread.

[0061] Figure 2 The comparison of sewing thread, copper wire, copper wire sewing thread, yarn-covered wire, conductive fiber, carbon fiber, and multi-strand carbon fiber in terms of diameter, conductor performance, and sewing adaptability is given respectively. As can be seen from the figure:

[0062] like Figure 2 As shown by the solid dots in the middle, in terms of electrical conductivity: copper wire, copper wire sewing thread, yarn-covered thread, and multi-strand carbon fiber can all meet the standards; Figure 2 As shown by the solid triangle in the middle, in terms of diameter: the diameters of copper wire, copper sewing thread, conductive fiber, and single-strand carbon fiber are all less than 0.2 mm; Figure 2 As shown in the hollow circles, in terms of sewing adaptability: sewing thread, copper wire sewing thread, and conductive fiber have better sewing properties.

[0063] After comparison, we can see that:

[0064] (1) The conductive fiber produced by electroplating or coating the conductive layer on the fiber surface has poor conductivity: Since the resistivity of the vacuum-plated layer on the fiber surface and the single-strand carbon fiber is very large, the resistance value per meter is much greater than 7.5 ohms. Therefore, it is suitable for making anti-static fabrics and electromagnetic shielding fabrics, but cannot be used to sew ultra-high frequency antennas.

[0065] (2) The thin copper wire with a diameter of 0.06 mm has poor tensile strength: The conductivity and softness of the thin copper wire with a diameter of 0.06 mm meet the standards, but its tensile strength is less than 1N, which makes it very easy to break during sewing. It is impossible to use high-speed sewing machines to mass-produce ultra-high frequency antennas on fabrics.

[0066] (3) The yarn-wrapped copper wire has poor sewing properties: The yarn-wrapped copper wire has good electrical conductivity and tensile strength, but its diameter is greater than 0.2 mm and its softness is poor. The surface of the sewn UHF antenna is obviously raised, making it impossible to mass-produce UHF antennas on a high-speed sewing machine.

[0067] In summary, the present invention uses copper sewing thread to manufacture the UHF antenna of the UHF tag in the footwear and clothing industry.

[0068] The copper wire sewing thread UHF antenna of the present invention has the following application characteristics and advantages:

[0069] (1) Ultra-high frequency performance

[0070] The copper wire sewing thread ultra-high frequency antenna of the present invention has high radio frequency identification sensitivity, and its bandwidth can be greater than 100 MHz under a -2dB bandwidth.

[0071] (2) Cost

[0072] 402 high-speed sewing thread costs 3 yuan for 10,000 yards, or 0.0004 yuan per meter. 0.06mm bare copper wire costs 0.005 yuan per meter. The cost of twisting the bare copper wire with the sewing thread is 50% of the price of the sewing thread and copper wire. Therefore, the material and twisting costs per meter of copper sewing thread are 0.0054 x 1.5 = 0.0081 yuan (this price fluctuates with market prices and is provided for illustrative purposes only).

[0073] Taking into account losses, the material cost for each meter of sewing thread used to make three UHF antennas is 0.0027 yuan, or 2.7 cents per UHF antenna. This cost is 1 / 6 of the cost of traditional UHF antennas made by chemically etching PET composite aluminum foil and 1 / 120 of the cost of carbon fiber UHF antennas.

[0074] (3) Environmental protection and efficiency

[0075] Compared with the chemical etching process of PET aluminum foil UHF antenna and multi-strand carbon fiber UHF antenna, the copper wire sewing thread UHF antenna of the present invention has five major advantages: (1) environmental protection, no chemical etching process, no waste liquid and wastewater; (2) the antenna is sewn on the label cloth, which is resistant to water washing, folding, pressing and ironing; (3) high production efficiency; (4) it is more convenient and quick to change the pattern and size of the UHF antenna; (5) companies with sewing machines can make UHF antennas and corresponding radio frequency tags on their products by themselves.

[0076] The copper wire sewing thread UHF antenna of the present invention contributes to the application of radio frequency tags in the laundry industry, footwear industry, handbag industry, home textile industry, cloth packaging industry, etc.:

[0077] A. This invention replaces the carbon fiber UHF antenna of the radio frequency laundry tag with a copper sewing thread UHF antenna, significantly reducing production costs. This promotes the adoption of radio frequency laundry tags in the laundry and linen industries, enabling automatic identification, error correction, and statistics at various process nodes, including receiving, washing, ironing, sorting, and delivery. This reduces staff, lowers costs, increases efficiency, and eliminates errors, allowing the labor-intensive laundry and linen industries to improve their information management.

[0078] B. The method for making the copper sewing thread UHF antenna of the present invention has created a new way for manufacturers in the clothing, footwear, home textiles, and handbag industries to make their own cloth radio frequency tags. This allows all companies with sewing machines to use copper sewing thread to make UHF antennas, which are then coupled with radio frequency resonant cavity assemblies to make cloth radio frequency tags. This significantly reduces the cost of making radio frequency tags and promotes the application and promotion of radio frequency identification technology.

[0079] C. The price of the cloth RFID tags used in this invention is lower than that of paper RFID tags, which is conducive to upgrading the RFID tags in the footwear and clothing industry from paper tags to cloth RFID tags. It allows the application of RFID technology to be expanded from warehousing and sales to washing and use process tracking services, promotes the footwear and clothing industry, linen industry, and handbag industry to adopt RFID technology and improve information management.

[0080] D. Some industries that provide cloth packaging, such as long-haul and logistics, as well as manufacturers of ton bags, express and postal container bags, and tobacco strapping, are unable to provide RFID tags for cloth packaging due to the high price of traditional cloth RFID tags. However, this invention, which uses copper sewing thread to create an UHF antenna, allows these companies to manufacture low-cost UHF tags on their products, promoting the informatization of management in the transportation and logistics industries.

Claims

1. A copper wire sewing line UHF antenna, characterized in that: The invention comprises a copper wire sewing thread, wherein the copper wire sewing thread is formed by twisting a bare copper wire and a sewing thread; The copper wire sewing thread is sewn on the label cloth substrate to form a copper wire sewing thread ultra-high frequency antenna.

2. The copper wire sewing line UHF antenna according to claim 1, characterized in that: The diameter of the sewing thread is 0.12 mm.

3. The copper wire sewing line UHF antenna according to claim 1, characterized in that: The electrical resistance of the copper wire sewing thread is less than 7.5 ohms per meter.

4. The copper wire sewing line UHF antenna according to claim 1, characterized in that: The copper wire sewing thread and the sewing bottom thread are synchronously sewn on the label cloth substrate, so that a sewing track of the copper wire sewing thread is formed on one side surface of the label cloth substrate.

5. The copper wire sewing thread UHF antenna according to claim 4, characterized in that: The length of the sewing track of the copper wire sewing thread of the straight sewing track is 100 mm to 120 mm.

6. The copper wire sewing thread UHF antenna according to claim 4, characterized in that: The sewing track length of the copper wire sewing thread with a zigzag or square wave sewing track is 60 mm to 90 mm.

7. The copper wire sewing line UHF antenna according to claim 1, characterized in that: The copper wire sewing thread is sewn separately on the label cloth substrate, so that the upper and lower surfaces of the label cloth substrate both have sewing tracks of the copper wire sewing thread.

8. The copper wire sewing thread UHF antenna according to claim 7, characterized in that: The length of the sewing track of the copper wire sewing thread of the straight sewing track is 80 mm to 90 mm.

9. A method for manufacturing a copper wire sewing thread ultra-high frequency antenna, characterized in that: include: S1. Select bare copper wire and sewing thread, and twist them to form copper wire sewing thread; S2, determining whether to use the copper wire sewing thread alone to sew the UHF antenna, or to use the copper wire sewing thread and the sewing bottom thread simultaneously to sew the UHF antenna; S3, determining the stitch track, stitch length, and sewing length of the sewing; S4, sewing copper wire sewing thread on the label cloth substrate to form an ultra-high frequency antenna.

10. The method for manufacturing the copper wire sewing thread UHF antenna according to claim 9, characterized in that: After the sewing is completed, it also includes the steps of determining the standard specifications of the UHF antenna manufacturing process: sewing UHF antennas with different parameters respectively and making sensitivity measurements; According to the measured recognition sensitivity of the UHF antenna, the stitch trajectory, stitch pitch, sewing length, and bare copper wire size are changed to obtain the sewing parameters with the best recognition sensitivity and formulate the process standards for the sewing antenna.

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