A method for fabricating an air curtain hook ear piece structure for a safety system and its integrated sewing process.

Abstract

This invention relates to the field of airbag manufacturing technology, and discloses a curtain airbag loop structure and an integrated sewing method for a safety system. The structure includes a loop and a curtain airbag. A dry high-friction coefficient coating is applied to the contact surfaces of the loop and the curtain airbag. This dry high-friction coefficient coating is formed by applying and drying a coating liquid, which consists of a friction enhancer, a temporary binder, and a volatile solvent carrier. The processing method includes: loop pretreatment; applying the coating liquid to the loop surface and drying to form a dry high-friction coefficient coating; and loop placement, curtain airbag placement, temporary fixing, and sewing steps. This invention, by constructing a dry high-friction interface at the contact surface, enhances the static friction between components, suppressing relative sliding. Simultaneously, its non-sticky characteristics avoid interference with the movement of the sewing needle, thereby ensuring the stability and accuracy of high-speed sewing and improving the product qualification rate.

Description

Technical Field

[0001] This invention relates to the field of airbag manufacturing technology, specifically to an air curtain hanger ear piece structure for a safety system and a method for integral sewing. Background Technology

[0002] Side curtain airbags are an important component of a vehicle's occupant restraint system. During the production of side curtain airbags, multiple mounting brackets are sewn onto the main curtain fabric to allow the airbag assembly to be installed on the vehicle's roof, A-pillars, B-pillars, or other similar locations. The positioning accuracy and stitching strength of the mounting brackets directly affect whether the side curtain airbag can deploy accurately during a collision.

[0003] In existing processing techniques, sewing equipment such as small pattern sewing machines are typically used to sew and fix the ear loops and safety curtains one by one. This single-piece processing method requires frequent repositioning and material handling when dealing with large-sized safety curtains with multiple ear loops, resulting in cumbersome procedures, low overall production efficiency, and difficulty in ensuring the consistency of positional accuracy among multiple ear loops.

[0004] To improve efficiency, the industry has attempted to use tooling in conjunction with a large-stroke template machine, hoping to clamp and sew multiple hanging tabs in one go. However, new technical challenges have arisen in implementing this process: the hanging tabs and the safety curtain fabric are two separate components, initially stacked only by positioning posts on the tooling. During the transport of the tooling loaded with materials within the workshop or its movement to the template machine's worktable, unavoidable vibrations cause slight relative displacement between the hanging tabs and the safety curtain fabric. Once this displacement occurs, it leads to misalignment of the preset positioning holes or limit grooves. Even with subsequent clamping of the tooling cover plate, the positioning deviation cannot be corrected, resulting in sewing stitches deviating from the intended path and causing batches of defective products.

[0005] To address the aforementioned relative displacement issue, an adhesive coating or temporary fixing glue was applied between the hanging tab and the fabric, bonding them together before sewing. While this method suppressed displacement to some extent, it introduced more serious process compatibility problems. During high-speed sewing, the sewing needle inevitably adheres to these sticky substances as it repeatedly punctures the fabric. The accumulation of these sticky substances increases the resistance of the sewing needle's movement, easily leading to skipped stitches, thread breakage, and contamination of the sewing needle tip and template machine equipment. This forces frequent production interruptions for cleaning, severely hindering the smoothness and high-speed operation of automated production processes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a structure for the air curtain hanging ear piece of a safety system and a method for integrated sewing. This solves the problem that when using tooling and a template machine to integrate the safety air curtain with multiple hanging ear pieces, lateral misalignment between components caused by tooling movement affects sewing accuracy and stability.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] The first aspect of this invention provides a curtain airbag hanger structure for a safety system, comprising a hanger and a safety airbag. The contact surface between the hanger and the safety airbag is coated with a dry high-friction coefficient coating. This dry high-friction coefficient coating is formed by applying and drying a coating liquid, which is composed of the following components by weight percentage:

[0009] Friction enhancer: 3.0wt%-8.0wt%;

[0010] Temporary adhesive: 0.5wt%-2.0wt%;

[0011] Volatile solvent carrier: 90.0wt%-96.5wt%.

[0012] By adopting the above technical solution, this invention aims to solve the positioning accuracy problem in automated sewing processes, where components are positioned on the tooling and then moved to the template machine. In existing technologies, temporary fixation relies solely on the vertical pressure applied by the cover plate. Under the vibration or inertia of the tooling movement, lateral shear displacement (misalignment in the XY axis direction) can easily occur between the hanging ear and the safety air curtain, causing the first limiting groove and the second limiting groove to not be accurately aligned, thus affecting the sewing quality.

[0013] The innovative principle of the structure provided by this invention lies in utilizing the aforementioned dry high-friction coefficient coating to effectively convert the vertical pressure (Z-axis) of the cover plate into extremely high lateral static friction force (XY-axis). Its working mechanism is as follows:

[0014] Preparation and drying of coating liquid: A volatile solvent carrier (such as isopropanol) is used to dissolve the temporary binder and uniformly disperse the insoluble friction enhancer (such as fumed silica particles).

[0015] Dry coating formation: After the coating liquid is applied to the surface of the ear loop and dries, the volatile solvent carrier is completely removed. The temporary adhesive then acts as a film-forming agent, forming an extremely thin, dry, and non-sticky polymer matrix on the surface of the ear loop.

[0016] Construction of the friction interface: Micron- or nano-sized particles of the friction enhancer are firmly anchored to the surface of the lug by the polymer matrix, forming a physically roughened micro-interface.

[0017] Friction generation: When the airbag is placed on the coating and the cover is flipped to apply vertical pressure, the hard particles of the friction enhancer produce a physical engagement effect with the fabric fibers on the bottom surface of the airbag.

[0018] Positioning Achievement: This physical meshing effect increases the static friction coefficient between the two contact surfaces of the lug and the safety air curtain. Therefore, during the tooling movement, the high static friction coefficient provides sufficient shear resistance, effectively resisting vibration and inertia, preventing lateral misalignment between components, and ensuring that limiting groove one and limiting groove two always maintain precise overlap before sewing.

[0019] Meanwhile, since the coating is dry and non-sticky, it will not contaminate the sewing needle of the template machine in the subsequent S5 step, nor will it cause excessive adhesion between parts, thus ensuring the accuracy and efficiency of the processing.

[0020] Preferably, the friction enhancer is selected from one of the following: having a specific surface area of ​​150 m². 2 / g-300m 2 The mixture consists of fumed silica ( / g) and hexagonal boron nitride with an average particle size of 1μm-10μm. By employing the above technical solution, fumed silica possesses a high specific surface area and an irregular agglomerated structure, while hexagonal boron nitride has a micron-sized plate-like structure. Both can provide more physical meshing points at the microscopic level, thereby improving the static friction coefficient.

[0021] Preferably, the temporary adhesive is high molecular weight polyvinylpyrrolidone. By adopting the above technical solution, high molecular weight polyvinylpyrrolidone has excellent film-forming ability and adhesion to the ear loop substrate, ensuring that the friction enhancer particles are firmly fixed on the surface after drying and will not easily fall off in subsequent processes.

[0022] Preferably, the volatile solvent carrier is selected from isopropanol and hydrofluoroether. By adopting the above technical solution, both isopropanol and hydrofluoroether have high evaporation rates and low surface tension, which is beneficial for the rapid wetting and spreading of the coating liquid on the ear-hanging substrate, and can achieve rapid drying, adapting to the pace of automated production.

[0023] Preferably, the thickness of the dry high-friction coefficient coating is 1μm-5μm. By adopting the above technical solution, the coating thickness is controlled at the micrometer level, which is sufficient to support the friction enhancer particles to achieve the friction function. On the other hand, the thickness is extremely thin and will not have a substantial impact on the total stacked thickness of the lugs and safety air curtain, nor will it interfere with the original positioning accuracy of the tooling and limiting post, while ensuring that the sewing needle can pass through without obstruction.

[0024] Secondly, the present invention provides a method for integrated sewing processing, comprising the following steps:

[0025] S1. Pretreatment of the ear piece: Coating the contact surface between the ear piece and the safety curtain with a layer of coating liquid, and forming a dry high friction coefficient coating by drying.

[0026] S2, Placement of the hanging piece: The hanging piece pre-treated in step S1 is placed on the fixture. The top of the fixture is fixedly connected with multiple positioning posts. Multiple limiting grooves are opened on the outer side of the hanging piece. The hanging piece passes through the limiting grooves through the positioning posts to complete the temporary fixation of the hanging piece.

[0027] S3. Placement of safety curtain: Place the safety curtain on the hanging ear piece. Multiple fixing ears are fixedly connected to the outside of the safety curtain. Multiple limiting grooves are opened on the outside of the fixing ears. The positioning post passes through the limiting groove to temporarily fix the safety curtain. The limiting groove and the limiting groove overlap.

[0028] S4. Temporary Fixing: A cover plate is rotatably connected to the top of the tooling. The cover plate is flipped onto the safety curtain. Multiple positioning grooves are provided on the outer side of the cover plate. The cover plate fixes the safety curtain and the hanging ear piece through the multiple positioning grooves.

[0029] S5. Sewing: Move the tooling to the template machine for sewing, and sew the safety air curtain and the hanging ear piece together through the sewing area opened on the outside of the cover plate.

[0030] By adopting the above technical solution, this method combines chemical pretreatment with mechanical positioning and automated sewing. In step S1, the dry, high-friction coefficient coating formed on the ear flaps allows the friction-enhancing agent particles within this coating to physically engage with the fabric surface of the safety air curtain when vertical pressure is applied by the cover plate in step S4. This physical engagement effect generates a high static friction coefficient, providing strong lateral shear resistance. Therefore, in step S5, when the tooling moves to the template machine, this shear resistance effectively prevents relative displacement between the ear flaps and the safety air curtain due to vibration or inertia, ensuring that the overlapping limiting grooves one and two from step S3 remain precisely aligned during sewing, thus improving processing stability and yield.

[0031] Preferably, the pretreatment step of the ear tab specifically involves: applying the coating liquid to the contact surface between the ear tab and the safety curtain using either precision spraying or dip coating; after applying the coating liquid, drying the coating liquid until the surface of the dry high-friction coefficient coating is non-sticky. By adopting the above technical solution, precision spraying or dip coating is a controllable application method suitable for industrial production, which helps to ensure the uniformity of the coating thickness. Drying to a non-sticky surface is a key technical feature to ensure the effectiveness of this method, ensuring that the components will not stick unexpectedly before pressure is applied, and that the dried coating will not contaminate the sewing needle of the template machine during sewing.

[0032] Preferably, the drying method in step S1 is a hot air circulating oven within an infrared drying channel, with a drying temperature of 40℃-70℃ and a drying time of 30 seconds-120 seconds. By adopting the above technical solution, this range of process parameters provides a balance. The lower limit of 40℃ ensures effective evaporation of volatile solvent carriers (such as isopropanol); the upper limit of 70℃ avoids excessively high temperatures that could cause thermal deformation or chemical degradation of the ear-mount substrate or temporary adhesive (such as PVP). The time range of 30 seconds-120 seconds is suitable for high-speed automated production cycles, achieving rapid drying.

[0033] Preferably, the preparation method of the coating liquid includes: placing a volatile solvent carrier in a stirring device; adding a temporary binder to the volatile solvent carrier and stirring to dissolve it, obtaining a binder solution; adding the friction enhancer to the binder solution to form a suspension; and subjecting the suspension to either high-shear or ultrasonic dispersion treatment to obtain the coating liquid. By adopting the above technical solution, this preparation step ensures the uniformity and stability of the coating liquid. The temporary binder is first dissolved to allow it to fully swell in the solvent to form a homogeneous solution; then the friction enhancer is added. High-shear or ultrasonic dispersion treatment is necessary to break up the agglomerates of the friction enhancer (especially fumed silica) in the raw material state, allowing it to be uniformly suspended in the binder solution with a smaller particle size. This is crucial for forming a uniform, high-friction dry coating in step S1.

[0034] Preferably, the stirring and dissolving speed is 300-500 rpm for 30-60 minutes; the high-shear and ultrasonic dispersion treatment time is 15-30 minutes, and the temperature is controlled at 20℃-25℃ during the treatment. By adopting the above technical solution, specific and repeatable process parameters are provided. A stirring speed of 300-500 rpm is sufficient to dissolve high molecular weight PVP, while excessively high speeds will introduce too many bubbles or excessive shear. A dispersion time of 15-30 minutes ensures sufficient particle dispersion. Dispersion treatment at 20℃-25℃ (room temperature) avoids the accumulation of heat generated by high shear or ultrasonic waves, preventing the volatile solvent carrier from evaporating excessively during the preparation process, thereby ensuring the accuracy and stability of the final component ratio of the coating liquid.

[0035] This invention provides a structure for the air curtain hanging ear piece of a safety system and a method for its integrated sewing process. It has the following beneficial effects:

[0036] 1. This invention solves the problems of low efficiency and inconsistent precision caused by sewing a single hanging piece in traditional small pattern sewing machines by using tooling fixation and a large-stroke template machine, and by using a dry high-friction coefficient coating pre-set on the hanging piece. It achieves one-time, integrated sewing of multiple hanging pieces, improving production efficiency and processing consistency.

[0037] 2. The present invention utilizes a dry high-friction coefficient coating formed on the contact surface between the ear piece and the safety air curtain. When vertical pressure is applied to the cover plate, the dry high-friction coefficient coating generates a high static friction coefficient to resist lateral shear force. This effectively prevents relative displacement between components during the process of the tooling moving to the template machine, ensuring that the first and second limiting grooves always maintain precise overlap before sewing, thereby improving the positioning accuracy and pass rate of the final product.

[0038] 3. The coating used in this invention is a dry, non-sticky coating, which avoids the coating material adhering to or contaminating the sewing needle of the template machine during subsequent sewing processes, ensuring smooth and high-speed operation of the sewing process, and does not interfere with the physical stacking of the ear loops and safety air curtains, thus having good process compatibility. Attached Figure Description

[0039] Figure 1 This is a perspective view of the present invention;

[0040] Figure 2 This is a schematic diagram of the cover plate of the present invention;

[0041] Figure 3 This is a schematic diagram of the explosion of the safety air curtain of the present invention;

[0042] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0043] Figure 5 for Figure 3 Enlarged diagram of point B in the middle.

[0044] Among them, 1. tooling; 2. positioning post; 3. cover plate; 4. positioning groove; 5. sewing area; 6. safety curtain; 7. fixing ear; 8. limit groove one; 9. hanging ear piece; 10. limit groove two. Detailed Implementation

[0045] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings, preparation examples, embodiments, comparative examples, and test examples. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0046] Preparation Examples 1-5:

[0047] Preparation Example 1:

[0048] This preparation example provides a coating liquid, which consists of 3.0 wt% of a friction enhancer (fumed silica, with a specific surface area of ​​150 m²). 2 The mixture was prepared by adding 0.5 wt% of a temporary binder (polyvinylpyrrolidone K90) and 96.5 wt% of a volatile solvent carrier (isopropanol), and included the following steps:

[0049] At 20°C, 96.5 parts by weight of isopropanol were placed in a reaction vessel equipped with a mechanical stirrer.

[0050] Start the mechanical stirrer at 300 rpm, slowly add 0.5 parts by weight of polyvinylpyrrolidone K90 to the isopropanol, and continue stirring for 30 minutes until completely dissolved to obtain the binder solution.

[0051] While stirring, slowly add 3.0 parts by weight of fumed silica to the binder solution to form a suspension;

[0052] The obtained suspension was transferred to an ultrasonic disperser and ultrasonically dispersed for 15 minutes under a water bath cooling condition at 20°C to obtain coating liquid A1.

[0053] Preparation Example 2:

[0054] This preparation example provides a coating liquid, which is prepared from 8.0 wt% of a friction enhancer (hexagonal boron nitride, average particle size 10 μm), 2.0 wt% of a temporary binder (polyvinylpyrrolidone K90), and 90.0 wt% of a volatile solvent carrier (hydrofluoroether HFE-7100), including the following steps:

[0055] At 25°C, 90.0 parts by weight of hydrofluoroether HFE-7100 were placed in a reactor equipped with a mechanical stirrer.

[0056] Start the mechanical stirrer at 500 rpm, slowly add 2.0 parts by weight of polyvinylpyrrolidone K90 to hydrofluoroether HFE-7100, and continue stirring for 60 minutes until completely dissolved to obtain the adhesive solution.

[0057] While stirring, slowly add 8.0 parts by weight of hexagonal boron nitride to the binder solution to form a suspension;

[0058] The obtained suspension was transferred to a high-shear disperser and subjected to high-shear dispersion treatment for 30 minutes under water bath cooling conditions at 25°C to obtain coating liquid A2.

[0059] Preparation Example 3:

[0060] This preparation example provides a coating liquid, which consists of 5.5 wt% of a friction enhancer (fumed silica, with a specific surface area of ​​220 m²). 2 The mixture was prepared by comprising the following steps: 1.25 wt% temporary binder (polyvinylpyrrolidone K90) and 93.25 wt% volatile solvent carrier (isopropanol).

[0061] At 22°C, 93.25 parts by weight of isopropanol were placed in a reactor equipped with a mechanical stirrer.

[0062] Start the mechanical stirrer at 400 rpm, slowly add 1.25 parts by weight of polyvinylpyrrolidone K90 to isopropanol, and continue stirring for 45 minutes until completely dissolved to obtain the binder solution.

[0063] While stirring, slowly add 5.5 parts by weight of fumed silica to the binder solution to form a suspension;

[0064] The obtained suspension was transferred to a high-shear disperser and subjected to high-shear dispersion treatment for 22 minutes under water bath cooling conditions at 22°C to obtain coating liquid A3.

[0065] Preparation Example 4:

[0066] This preparation example provides a coating liquid, which is prepared from 6.0 wt% of a friction enhancer (hexagonal boron nitride, average particle size 1 μm), 1.0 wt% of a temporary binder (polyvinylpyrrolidone K90), and 93.0 wt% of a volatile solvent carrier (hydrofluoroether HFE-7100), including the following steps:

[0067] At 23°C, 93.0 parts by weight of hydrofluoroether HFE-7100 were placed in a reactor equipped with a mechanical stirrer.

[0068] Start the mechanical stirrer at 350 rpm, slowly add 1.0 part by weight of polyvinylpyrrolidone K90 to hydrofluoroether HFE-7100, and continue stirring for 50 minutes until completely dissolved to obtain the adhesive solution.

[0069] While stirring, slowly add 6.0 parts by weight of hexagonal boron nitride to the binder solution to form a suspension;

[0070] The obtained suspension was transferred to an ultrasonic disperser and ultrasonically dispersed for 25 minutes under a water bath cooling condition of 23°C to obtain coating liquid A4.

[0071] Preparation Example 5:

[0072] This preparation example provides a coating liquid, which consists of 4.0 wt% of a friction enhancer (fumed silica, with a specific surface area of ​​300 m²). 2 The mixture was prepared by adding 1.5 wt% of a temporary binder (polyvinylpyrrolidone K90) and 94.5 wt% of a volatile solvent carrier (hydrofluoroether HFE-7100), and included the following steps:

[0073] At 24°C, 94.5 parts by weight of hydrofluoroether HFE-7100 were placed in a reactor equipped with a mechanical stirrer.

[0074] Start the mechanical stirrer at 450 rpm, slowly add 1.5 parts by weight of polyvinylpyrrolidone K90 to hydrofluoroether HFE-7100, and continue stirring for 40 minutes until completely dissolved to obtain the adhesive solution.

[0075] While stirring, slowly add 4.0 parts by weight of fumed silica to the binder solution to form a suspension;

[0076] The obtained suspension was transferred to an ultrasonic disperser and ultrasonically dispersed for 20 minutes under a water bath cooling condition of 24°C to obtain coating liquid A5.

[0077] Examples 1-5:

[0078] Example 1:

[0079] Reference Appendix Figure 1-5 This embodiment provides a method for integral sewing of the air curtain hook ear structure for a safety system. The dry high-friction coefficient coating used is formed by coating liquid A1, and includes the following steps:

[0080] S1. Pre-treatment of ear piece 9: Using a precision spraying method, the coating liquid A1 is evenly applied to the contact surface between the ear piece 9 and the safety curtain 6; then the sprayed ear piece 9 is placed in a hot air circulating oven and dried at 40°C for 30 seconds until the coating surface is no longer sticky, forming a dry high friction coefficient coating with a thickness of 1µm.

[0081] S2, Placement of hanging ear piece 9: Place the hanging ear piece 9, which has been pretreated in step S1, on the fixture 1. Multiple positioning posts 2 are fixedly connected to the top of the fixture 1. Multiple limiting grooves 10 are opened on the outer side of the hanging ear piece 9. The hanging ear piece 9 passes through the limiting grooves 10 through the positioning posts 2 to complete the temporary fixation of the hanging ear piece 9.

[0082] S3. Placement of safety curtain 6: Place safety curtain 6 on the hanging ear piece 9. Multiple fixing ears 7 are fixedly connected to the outside of safety curtain 6. Multiple limiting grooves 1 8 are opened on the outside of the fixing ears 7. The positioning post 2 passes through the limiting grooves 1 8 to temporarily fix the safety curtain 6. The limiting grooves 1 8 and 2 10 overlap.

[0083] S4. Temporary fixing: The top of the tooling 1 is rotatably connected to the cover plate 3. The cover plate 3 is flipped onto the safety curtain 6. The multiple positioning grooves 4 on the outside of the cover plate 3 cooperate with the positioning column 2 to apply pressure to fix the safety curtain 6 and the hanging ear piece 9.

[0084] S5. Sewing: The moving fixture 1 is sewn to the template machine. The safety air curtain 6 and the hanging ear piece 9 are sewn together through the sewing area 5 opened on the outside of the cover plate 3 to form a whole.

[0085] Example 2:

[0086] Reference Appendix Figure 1-5 This embodiment provides a method for integral sewing of the air curtain hook ear piece structure for a safety system. The dry high-friction coefficient coating used is formed by coating liquid A2, and includes the following steps:

[0087] S1. Pretreatment of ear tab 9: The coating liquid A2 is applied to the contact surface between the ear tab 9 and the safety curtain 6 by dip coating. Then the dip-coated ear tab 9 is sent into the infrared drying channel and dried at 70°C for 120 seconds until the coating surface is no longer sticky, forming a dry high friction coefficient coating with a thickness of 3µm.

[0088] S2, Placement of hanging ear piece 9: Place the hanging ear piece 9, which has been pretreated in step S1, on the fixture 1. Multiple positioning posts 2 are fixedly connected to the top of the fixture 1. Multiple limiting grooves 10 are opened on the outer side of the hanging ear piece 9. The hanging ear piece 9 passes through the limiting grooves 10 through the positioning posts 2 to complete the temporary fixation of the hanging ear piece 9.

[0089] S3. Placement of safety curtain 6: Place safety curtain 6 on the hanging ear piece 9. Multiple fixing ears 7 are fixedly connected to the outside of safety curtain 6. Multiple limiting grooves 1 8 are opened on the outside of the fixing ears 7. The positioning post 2 passes through the limiting grooves 1 8 to temporarily fix the safety curtain 6. The limiting grooves 1 8 and 2 10 overlap.

[0090] S4. Temporary fixing: The top of the tooling 1 is rotatably connected to the cover plate 3. The cover plate 3 is flipped onto the safety curtain 6. The multiple positioning grooves 4 on the outside of the cover plate 3 cooperate with the positioning column 2 to apply pressure to fix the safety curtain 6 and the hanging ear piece 9.

[0091] S5. Sewing: The moving fixture 1 is sewn to the template machine. The safety air curtain 6 and the hanging ear piece 9 are sewn together through the sewing area 5 opened on the outside of the cover plate 3 to form a whole.

[0092] Example 3:

[0093] Reference Appendix Figure 1-5 This embodiment provides a method for integral sewing of the air curtain hook ear piece structure for a safety system. The dry high-friction coefficient coating used is formed by coating liquid A3, and includes the following steps:

[0094] S1. Pre-treatment of ear piece 9: Using a precision spraying method, the coating liquid A3 is evenly applied to the contact surface between the ear piece 9 and the safety curtain 6; then the sprayed ear piece 9 is placed in a hot air circulating oven and dried at 55°C for 75 seconds until the coating surface is no longer sticky, forming a dry high friction coefficient coating with a thickness of 2µm.

[0095] S2, Placement of hanging ear piece 9: Place the hanging ear piece 9, which has been pretreated in step S1, on the fixture 1. Multiple positioning posts 2 are fixedly connected to the top of the fixture 1. Multiple limiting grooves 10 are opened on the outer side of the hanging ear piece 9. The hanging ear piece 9 passes through the limiting grooves 10 through the positioning posts 2 to complete the temporary fixation of the hanging ear piece 9.

[0096] S3. Placement of safety curtain 6: Place safety curtain 6 on the hanging ear piece 9. Multiple fixing ears 7 are fixedly connected to the outside of safety curtain 6. Multiple limiting grooves 1 8 are opened on the outside of the fixing ears 7. The positioning post 2 passes through the limiting grooves 1 8 to temporarily fix the safety curtain 6. The limiting grooves 1 8 and 2 10 overlap.

[0097] S4. Temporary fixing: The top of the tooling 1 is rotatably connected to the cover plate 3. The cover plate 3 is flipped onto the safety curtain 6. The multiple positioning grooves 4 on the outside of the cover plate 3 cooperate with the positioning column 2 to apply pressure to fix the safety curtain 6 and the hanging ear piece 9.

[0098] S5. Sewing: The moving fixture 1 is sewn to the template machine. The safety air curtain 6 and the hanging ear piece 9 are sewn together through the sewing area 5 opened on the outside of the cover plate 3 to form a whole.

[0099] Example 4:

[0100] Reference Appendix Figure 1-5 This embodiment provides a method for integral sewing of the air curtain hook ear structure for a safety system. The dry high-friction coefficient coating used is formed by coating liquid A4, and includes the following steps:

[0101] S1. Pretreatment of ear tab 9: The coating liquid A4 is applied to the contact surface between the ear tab 9 and the safety curtain 6 by dip coating. Then the dip-coated ear tab 9 is sent into the infrared drying channel and dried at 60°C for 90 seconds until the coating surface is no longer sticky, forming a dry high friction coefficient coating with a thickness of 4µm.

[0102] S2, Placement of hanging ear piece 9: Place the hanging ear piece 9, which has been pretreated in step S1, on the fixture 1. Multiple positioning posts 2 are fixedly connected to the top of the fixture 1. Multiple limiting grooves 10 are opened on the outer side of the hanging ear piece 9. The hanging ear piece 9 passes through the limiting grooves 10 through the positioning posts 2 to complete the temporary fixation of the hanging ear piece 9.

[0103] S3. Placement of safety curtain 6: Place safety curtain 6 on the hanging ear piece 9. Multiple fixing ears 7 are fixedly connected to the outside of safety curtain 6. Multiple limiting grooves 1 8 are opened on the outside of the fixing ears 7. The positioning post 2 passes through the limiting grooves 1 8 to temporarily fix the safety curtain 6. The limiting grooves 1 8 and 2 10 overlap.

[0104] S4. Temporary fixing: The top of the tooling 1 is rotatably connected to the cover plate 3. The cover plate 3 is flipped onto the safety curtain 6. The multiple positioning grooves 4 on the outside of the cover plate 3 cooperate with the positioning column 2 to apply pressure to fix the safety curtain 6 and the hanging ear piece 9.

[0105] S5. Sewing: The moving fixture 1 is sewn to the template machine. The safety air curtain 6 and the hanging ear piece 9 are sewn together through the sewing area 5 opened on the outside of the cover plate 3 to form a whole.

[0106] Example 5:

[0107] Reference Appendix Figure 1-5 This embodiment provides a method for integral sewing of the air curtain hook ear structure for a safety system. The dry high-friction coefficient coating used is formed by coating liquid A5, and includes the following steps:

[0108] S1. Pretreatment of ear tab 9: The coating liquid A5 is applied to the contact surface between the ear tab 9 and the safety curtain 6 by dip coating. The lifting speed is controlled to allow more coating liquid to adhere. Then the dip-coated ear tab 9 is sent into the infrared drying channel and dried at 65°C for 100 seconds until the coating surface is no longer sticky, forming a dry high friction coefficient coating with a thickness of 5µm.

[0109] S2, Placement of hanging ear piece 9: Place the hanging ear piece 9, which has been pretreated in step S1, on the fixture 1. Multiple positioning posts 2 are fixedly connected to the top of the fixture 1. Multiple limiting grooves 10 are opened on the outer side of the hanging ear piece 9. The hanging ear piece 9 passes through the limiting grooves 10 through the positioning posts 2 to complete the temporary fixation of the hanging ear piece 9.

[0110] S3. Placement of safety curtain 6: Place safety curtain 6 on the hanging ear piece 9. Multiple fixing ears 7 are fixedly connected to the outside of safety curtain 6. Multiple limiting grooves 1 8 are opened on the outside of the fixing ears 7. The positioning post 2 passes through the limiting grooves 1 8 to temporarily fix the safety curtain 6. The limiting grooves 1 8 and 2 10 overlap.

[0111] S4. Temporary fixing: The top of the tooling 1 is rotatably connected to the cover plate 3. The cover plate 3 is flipped onto the safety curtain 6. The multiple positioning grooves 4 on the outside of the cover plate 3 cooperate with the positioning column 2 to apply pressure to fix the safety curtain 6 and the hanging ear piece 9.

[0112] S5. Sewing: The moving fixture 1 is sewn to the template machine. The safety air curtain 6 and the hanging ear piece 9 are sewn together through the sewing area 5 opened on the outside of the cover plate 3 to form a whole.

[0113] Comparative Examples 1-4:

[0114] Comparative Example 1:

[0115] Compared with Example 1, the difference is that the pretreatment of the ear loop 9 in step S1 is not performed, that is, no coating is applied to the ear loop 9, while the remaining steps S2 to S5 are the same.

[0116] Comparative Example 2:

[0117] Compared with Example 3, the difference is that the coating liquid used in step S1 is replaced with a coating liquid without friction enhancer (the coating liquid is prepared from 1.25 wt% polyvinylpyrrolidone K90 and 98.75 wt% isopropanol), and all other aspects are the same.

[0118] Comparative Example 3:

[0119] Compared with Example 3, the difference is that the coating liquid used in step S1 is replaced with an aqueous acrylic emulsion (40% solid content), which forms a viscous coating after drying. All other aspects are the same.

[0120] Comparative Example 4:

[0121] Compared with Example 2, the difference is that the coating liquid used in step S1 is replaced with a coating liquid without friction enhancer (the coating liquid is prepared by 2.0 wt% polyvinylpyrrolidone K90 and 98.0 wt% hydrofluoroether HFE-7100), and all other aspects are the same.

[0122] Test Example 1-2:

[0123] Test Example 1: Sewing Compatibility Test (Feasibility Test)

[0124] This test case aims to evaluate the performance of the dry high-friction coefficient coating at different sewing speeds during the integrated sewing process of the safety curtain 6 loops, in order to verify the practicality of this solution.

[0125] Test method:

[0126] Prepare test samples: Select the ear loop 9 and the safety curtain 6 fabric that meet the production standards, and prepare the coated ear loop 9 according to the steps of Examples 1-5 and Comparative Examples 1-3. Temporarily fix the prepared coated ear loop 9 and the safety curtain 6 fabric according to the steps of their respective examples and comparative examples.

[0127] Sewing Operation: Place the temporarily fixed sample on the template machine worktable of the industrial sewing machine; set the sewing machine speed to: slow (800 rpm), medium (1200 rpm), and fast (1600 rpm); at each speed, perform sewing operations on each sample type, with the stitch length uniformly set to 50 mm. Observe whether the following abnormalities occur during the sewing process: skipped stitches during sewing, fabric displacement causing the stitch to deviate from the preset path during sewing, thread breakage during sewing, and uneven or overlapping stitches after sewing.

[0128] Results Record: Record any abnormalities that occurred for each sample at different sewing speeds.

[0129] Test data:

[0130] Table 1. Sewing compatibility test results

[0131]

[0132] Summarize:

[0133] The results of this test demonstrate that pretreatment of the ear loop 9 with the dry high-friction coefficient coating provided in this solution can improve the compatibility of the integrated sewing process of the safety curtain 6 ear loop structure. The coated ear loop 9 prepared in Examples 1-3 exhibited good sewing compatibility at different sewing speeds, with no observed abnormalities such as skipped stitches, fabric displacement, thread breakage, or uneven / stitched textures. This proves that the applied dry high-friction coefficient coating effectively enhances the friction between the ear loop 9 and the safety curtain 6 fabric, thereby providing a stable relative position during sewing and ensuring sewing quality and efficiency.

[0134] Comparative Example 1 (without coating) and Comparative Example 2 (with coating without friction enhancer) showed occasional fabric displacement and uneven stitches at lower sewing speeds. At higher sewing speeds, they exhibited frequent skipped stitches, fabric displacement, thread breakage, and severe stitch quality problems. This reflects that in the absence of sufficient friction, the fabric shifts relative to the sewing needle during piercing or during sewing due to sewing machine vibration, leading to inaccurate or interrupted sewing. Comparative Example 3 used a water-based acrylic emulsion coating, which became sticky after drying. This increased resistance during needle piercing, making skipped stitches and thread breakage more likely. Furthermore, the stickiness of the coating caused the fabric to tear or stick together during movement, severely affecting sewing compatibility.

[0135] This solution employs a dry, high-friction coefficient coating. By introducing a high-friction enhancer, this coating establishes a stable friction interface between the ear loop 9 and the safety curtain 6, avoiding problems such as needle sticking, increased resistance, and fabric damage caused by traditional adhesive coatings. By increasing the static friction coefficient of the contact surface, even under high-speed sewing and mechanical vibration conditions, the relative sliding between the ear loop 9 and the safety curtain 6 can be effectively suppressed, thus ensuring the accuracy, continuity, and stability of the sewing process. This achieves integrated and efficient sewing of the safety curtain 6's ear loop structure.

[0136] Test Example 2: Test on resistance to transverse shear displacement (effect comparison)

[0137] This test case aims to quantitatively evaluate the relative displacement between the lug 9 treated with different coatings and the fabric of the safety curtain 6 when subjected to a constant lateral shear force, in order to verify the technical effectiveness of this solution in suppressing relative slippage.

[0138] Test method:

[0139] Prepare test samples: Select the ear loop material 9 and the safety curtain 6 fabric that meet the production standards, and cut them into 50mm×50mm square samples respectively. According to the steps of Examples 1-5 and Comparative Examples 1-4, prepare coated ear loop samples and untreated ear loop samples respectively. Stack the ear loop samples and the safety curtain 6 fabric samples so that the coated surface is in contact with the fabric surface.

[0140] Test apparatus and loading: A universal testing machine equipped with a horizontal shearing fixture was used; the stacked samples (with the ear piece 9 sample at the bottom and the fabric sample at the top) were placed horizontally on the lower platform of the fixture; a vertical load of 50N was applied to the upper surface of the fabric sample to simulate the clamping pressure of the sewing fixture 1; the upper fixture of the testing machine was fixed to the fabric sample and the lower fixture was fixed to the ear piece 9 sample.

[0141] Test execution and data acquisition: Start the testing machine and apply a horizontal shear force to the lower clamp at a speed of 0.5 mm / min until the shear force reaches 5 N; maintain a constant transverse shear force of 5 N for 30 seconds; use a laser displacement sensor to measure and record the maximum transverse displacement of the fabric sample relative to the ear tab 9 sample during this 30-second period; repeat the test 5 times for each sample type and record its displacement data.

[0142] Test data:

[0143] Table 2. Test results of resistance to transverse shear displacement

[0144]

[0145] Summarize:

[0146] Test data clearly show that the relative displacement between the lug 9 treated with the dry high-friction coefficient coating provided by this solution and the safety curtain 6 fabric is effectively suppressed when subjected to lateral shear force. The lateral displacement of the samples in Examples 1 to 5 is less than 0.1 mm, lower than all comparative sample samples. In contrast, the displacement of Comparative Example 1 without any treatment and Comparative Example 3 using water-based acrylic emulsion reached 3.82 mm and 4.55 mm respectively, exhibiting an extremely unstable contact interface, objectively quantifying the technical effect of this solution in improving the resistance to lateral shear displacement.

[0147] The mechanism by which this technical effect is achieved lies in the fact that the friction enhancer (e.g., fumed silica, hexagonal boron nitride) in the dry high-friction coefficient coating forms a micro-rough structure on the surface of the lug 9. When these microstructures come into contact with the fibers of the safety curtain 6 fabric, they significantly increase the static friction coefficient of the contact interface through the combined action of mechanical engagement and van der Waals forces. Therefore, even when an external shear force sufficient to cause macroscopic sliding is applied, this high-friction interface still provides sufficient resistance to maintain the relative stillness of the components. Comparative Examples 2 and 4, containing only a temporary binder without the friction enhancer, exhibited displacements (2.15 mm and 2.31 mm, respectively) far greater than those in the examples, demonstrating that the friction enhancer is a key element in achieving high shear resistance.

[0148] This solution solves the problem of minute displacement between the ear loop 9 and the safety curtain 6 fabric caused by vibration and needle thrust during sewing by constructing a dry, non-adhesive coating with a high coefficient of friction on the surface of the ear loop 9. The extremely low lateral displacement measured in Test Example 2 directly corresponds to the high stability of the component position during sewing. This stability is a technical prerequisite for ensuring accurate sewing stitches, avoiding skipped stitches and thread breaks, and ultimately achieving high-quality integrated sewing of the safety curtain 6 ear loop structure. This method does not rely on adhesive for fixation, thus avoiding the problem of the adhesive coating interfering with the movement of the sewing needle that occurred in Comparative Example 3, ensuring the smoothness and reliability of the process.

Claims

1. A structure for an air curtain hanger in a safety system, characterized in that, include: The ear loops (9) and the safety curtain (6) are coated with a dry high-friction coefficient coating on their contact surfaces. The dry high-friction coefficient coating is formed by applying and drying a coating liquid, which is composed of the following components by weight percentage: Friction enhancer: 3.0wt%-8.0wt%; Temporary adhesive: 0.5wt%-2.0wt%; Volatile solvent carrier: 90.0wt%-96.5wt%; The friction enhancer is selected from materials with a specific surface area of ​​150 m². 2 / g-300m 2 / g of fumed silica or hexagonal boron nitride with an average particle size of 1μm-10μm; The temporary adhesive is high molecular weight polyvinylpyrrolidone; The volatile solvent carrier is selected from isopropanol and hydrofluoroether.

2. The air curtain hanger ear plate structure for a safety system according to claim 1, characterized in that, The thickness of the dry high friction coefficient coating is 1μm-5μm.

3. A method for integrated sewing processing, characterized in that, The air curtain hanger ear plate structure for a safety system according to any one of claims 1-2 includes the following steps: S1. Pretreatment of ear loop (9): Coating the contact surface of the ear loop (9) and the safety curtain (6) with a layer of coating liquid and drying to form a dry high friction coefficient coating. S2, Placement of the ear piece (9): The ear piece (9) pretreated in step S1 is placed on the fixture (1). The fixture (1) is fixedly connected to a number of positioning posts (2) on the top. The ear piece (9) is provided with a number of limiting grooves (10) on the outside. The ear piece (9) passes through the limiting grooves (10) through the positioning posts (2) to complete the temporary fixation of the ear piece (9). S3, Safety curtain (6) placement: Safety curtain (6) is placed on the hanging ear piece (9). Multiple fixing ears (7) are fixedly connected to the outside of the safety curtain (6). Multiple limiting grooves (8) are opened on the outside of the fixing ears (7). The positioning column (2) passes through the limiting groove (8) to complete the temporary fixation of the safety curtain (6). The limiting groove (8) and the limiting groove (10) overlap. S4. Temporary fixing: The tool (1) is rotatably connected to a cover plate (3). The cover plate (3) is flipped onto the safety curtain (6). Multiple positioning grooves (4) are provided on the outer side of the cover plate (3). The cover plate (3) fixes the safety curtain (6) and the hanging ear piece (9) through the multiple positioning grooves (4). S5. Sewing: Move the tool (1) to the template machine for sewing. The safety curtain (6) and the hanging ear piece (9) are sewn together through the sewing area (5) opened on the outside of the cover plate (3).

4. The method for integrated sewing processing according to claim 3, characterized in that, The specific steps for pre-treating the ear loop (9) are as follows: The coating liquid is applied to the contact surface between the ear piece (9) and the safety curtain (6) using either precision spraying or dip coating. After the coating liquid is applied, it is dried until the surface of the dry high-friction coefficient coating is non-sticky.

5. The method for integrated sewing processing according to claim 4, characterized in that, The drying method in step S1 is a hot air circulating oven in the infrared drying channel, with a drying temperature of 40℃-70℃ and a drying time of 30 seconds-120 seconds.

6. The method for integrated sewing processing according to claim 3, characterized in that, The preparation method of the coating liquid includes: Place the volatile solvent carrier in the stirring device; A temporary binder is added to the volatile solvent carrier and stirred to dissolve, thereby obtaining a binder solution; The friction enhancer is added to the adhesive solution to form a suspension; The coating liquid is obtained by subjecting the suspension to either high-shear or ultrasonic dispersion treatment.

7. The method for integrated sewing processing according to claim 6, characterized in that, The stirring and dissolving speed is 300-500 rpm, and the time is 30-60 minutes; The high shear and ultrasonic dispersion treatment takes 15-30 minutes, and the temperature is controlled at 20℃-25℃ during the treatment.

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