Sandwich type weather stripping and method of making same

Abstract

The application discloses a sandwich type windproof sealing strip and a preparation method thereof, and belongs to the technical field of windproof sealing strips of the roll-back / roll-on type product, and the sandwich type windproof sealing strip comprises a sealing strip body in the form of a long flexible belt, the sealing strip body is a multilayer sandwich structure, the multilayer sandwich structure comprises a hydrophobic thermoplastic plastic sheet in the middle and an upper layer waterproof functional fabric belt arranged on the plastic sheet, the plastic sheet is a flexible sheet and is provided with pre-punched holes with a hole diameter smaller than the diameter of a sewing needle; the upper layer fabric belt and the plastic sheet are penetrated and locked by a sewing thread coated by hot melt glue, the sewing thread is fused by hot pressing and fills the pre-punched holes and is solidified, a mechanical lock catch that mutually embeds the sewing thread and the plastic sheet is formed in the pre-punched holes, and a stitch hole gap leakage channel is eliminated; a mounting end of the sealing strip body is provided with a clamping groove matched with a roll-back circular tube, and a free end is in the form of a flat straight edge, a soft plastic sheet sandwich structure is adopted, and the sealing strip is flexible, self-recoverable, sealing and anti-seepage, and does not damage a track.

Description

Technical Field

[0001] This invention relates to the field of windproof sealing strip technology, and in particular to a sandwich-type windproof sealing strip and its preparation method. Background Technology

[0002] With the continuous upgrading of building energy efficiency and window airtightness standards, roll-up sunshades are widely used in home decoration, sunrooms, curtain walls, and outdoor sunshade applications. The gaps between the sides of the curtain and the track are the main channels for cold air penetration, rainwater backflow, and mosquito entry. The side windproof sealing strip has become a core component determining the windproof, waterproof, soundproof, and light-blocking performance of the sunshade. At present, the industry mainly uses three traditional processes for side sealing of roll-up sunshades: direct sewing of fabric, hot-melt zipper composite, and hot-melt metal strip wrapped with fabric. However, all three existing structures have insurmountable structural and usage defects, and cannot meet the diverse needs of lightweight narrow frame profiles, waterproof sealing, smooth rolling, and long-term weather resistance, as detailed below.

[0003] Traditional sewing solutions involve directly stitching plastic sheets or webbing to the fabric, leaving numerous gaps where the threads pass through. The annular gaps between the sewing thread and the needle hole create leakage channels. When breathable mesh fabrics are stretched by external forces, the fabric surface is prone to separation from the sealing sheet, failing to achieve effective water and wind protection. Under outdoor rain and strong wind conditions, air leakage and water seepage problems are prominent, resulting in poor sealing and protection performance.

[0004] Hot-melt zipper bonding involves hot-melt welding of the coated zipper to the fabric. To ensure a strong weld, different zippers use different webbing and processes. During rewinding, the material has a large springback, and the zipper teeth accumulate after rewinding, which can easily cause deformation of easily deformable fabrics or deformation when rewinding or opening, severely hindering the round tube winding operation. Nylon coated zippers are relatively heavy, and the hot-melt adhesive penetrates into the webbing when heated. Due to the effects of environmental thermal expansion and contraction, the zipper and the fabric deform asynchronously, which can easily pull the fabric to twist and deform, resulting in a large amount of rework later. At the same time, the zipper structure assembly requires a larger outer diameter of the rewinding round tube aluminum profile, which cannot adapt to the current product development trend of lightweight and ultra-narrow guide rails.

[0005] The metal strip-wrapped fabric hot-melt structure uses a thin metal strip as the supporting substrate, covered with an outer layer of fabric, which is then hot-meltted together with the fabric. The metal strip is hard and easily tears the outer fabric and scratches the inner wall of the guide rail during reciprocating sliding within the aluminum or plastic guide rail. The steel strip and outer fabric are bonded with adhesive; after repeated bending, rolling, and friction over a long period, the adhesive may detach and the edges may open. Furthermore, the metal strip has no self-recovery ability after being deformed by external force; once deformed, the entire sealing strip is rendered unusable. In addition, the metal strip-wrapped fabric hot-melt structure is difficult to manufacture and extremely costly.

[0006] With the upgrading market demand for miniaturization, narrow track, and outdoor waterproofing and UV protection in the sunshade curtain industry, the shortcomings of the existing three windproof sealing structures in terms of roll-up adaptability, sealing performance, wear resistance, durability and versatility in various scenarios are becoming increasingly prominent. The industry urgently needs a new type of windproof sealing strip structure and its preparation method that takes into account flexibility, self-healing, sealing and seepage prevention, adaptability to small-sized profiles and multiple shading conditions. Summary of the Invention

[0007] This invention provides a sandwich-type windproof sealing strip and its preparation method to solve the technical problems in the prior art, such as insufficient sealing of existing sewing solutions, easy deformation of fabric due to the accumulation of chain teeth after rewinding of hot melt zipper solutions, affecting winding, and scratching of the track and inability to recover after deformation of metal steel strip solutions.

[0008] The present invention employs the following technical solution: a sandwich-type windproof sealing strip, comprising a long strip-shaped sealing strip body, wherein the sealing strip body has a multi-layer sandwich structure; the multi-layer sandwich structure includes a centrally located hydrophobic thermoplastic sheet and a double-sided adhesive-coated waterproof functional webbing placed on the upper layer of the plastic sheet; the plastic sheet is a flexible sheet material and has pre-punched holes with a diameter smaller than that of a sewing needle along its length; the upper webbing and the plastic sheet are locked together by a sewing thread treated with hot melt adhesive, the sewing thread is hot-pressed and melted and filled into the pre-punched holes and then cured, forming a mechanical lock in the pre-punched holes that interlocks the sewing thread and the plastic sheet; the mounting end of the sealing strip body is provided with a groove that mates with a rewinding tube, and the free end of the sealing strip body has a flat straight edge that can slide within a guide rail.

[0009] Furthermore, the plastic sheet is a flexible thermoplastic sheet, and the diameter of the pre-punched hole is smaller than the diameter of the sewing needle that is matched with the sewing thread. When the sewing needle punctures, it forms an interference fit with the pre-punched hole.

[0010] Furthermore, the functional webbing is clamped and limited on the upper and lower sides of the plastic sheet by the multi-layer sandwich structure, and both sides of the functional webbing are provided with an adhesive layer.

[0011] Furthermore, the functional webbing is a full-light-blocking webbing, a semi-light-blocking webbing, or a heat-insulating, UV-resistant, high-temperature-resistant, wear-resistant, and wrinkle-resistant webbing, and can be independently disassembled and replaced via the clamping and limiting mechanism.

[0012] Furthermore, the plastic sheet is a transparent plastic sheet, the sewing thread is polyester thread wrapped with hot melt adhesive, and the width of the plastic sheet is cut according to the guide rail specifications.

[0013] Furthermore, the thickness of the plastic sheet is 0.15 mm to 2.0 mm.

[0014] This invention also provides a method for preparing a sandwich-type windproof sealing strip, which includes the following steps: pre-punching holes with a diameter smaller than that of a sewing needle are formed on a hydrophobic thermoplastic sheet; polyester sewing thread is impregnated with hot melt adhesive and cured to obtain hot melt adhesive-coated sewing thread; a lower layer of double-sided adhesive-coated functional webbing, the plastic sheet, and an upper layer of double-sided adhesive-coated functional webbing are sequentially stacked and aligned, and the hot melt adhesive-coated sewing thread is used to penetrate the two layers to complete the sewing composite; the surface of the sewn composite plastic sheet is plasma activated, and hot melt adhesive is filled into the pre-punched holes; the semi-finished product is fed into a segmented temperature-controlled hot pressing device, passing sequentially through a hot pressing zone, a room temperature transition zone, and a water-cooling zone, so that the hot melt adhesive on the sewing thread is heated and melted to fill the pre-punched holes, and then cooled and cured in the pre-punched holes to form a mechanical lock.

[0015] Furthermore, the temperature of the hot pressing zone of the segmented temperature-controlled hot pressing equipment is 160 ℃ to 180 ℃, the ambient temperature transition zone is an ambient temperature transition zone, and the water cooling zone is a water cooling zone.

[0016] Furthermore, the functional webbing is cut by ultrasonic slitting, with an ultrasonic frequency of 20 kHz and a slitting cutter angle of 120°.

[0017] Furthermore, the sewing thread is impregnated with hot melt adhesive in a constant temperature environment of ±30 ℃, and then left to stand at room temperature for 24 h to allow the hot melt adhesive to crystallize and solidify.

[0018] The above-described at least one technical solution adopted in the embodiments of the present invention can achieve the following beneficial effects:

[0019] I. Facilitates lightweight profile design. This invention adopts a soft plastic sheet sandwich structure, allowing the rewinding round tube and pull beam aluminum material to be made in narrower specifications with thicker tube walls, improving the rotation stability of the rewinding shaft. It can be equipped with ultra-narrow guide rails, overcoming the limitation of requiring wider profiles for zippers and metal steel strips.

[0020] II. Excellent sealing, waterproofing, and windproof performance. Utilizing adhesive-backed stitching and a hot-press sealing process, the pre-punched holes in the plastic sheet are filled with hot melt adhesive to achieve a complete seal, preventing water and air leakage through pinholes; the interlayer webbing is hydrophobic and UV-resistant, preventing oil and water penetration, resulting in a sealing effect far superior to ordinary sewn structures.

[0021] 3. Excellent sliding protection, without damaging the track or fabric. The plastic sheet has good toughness and self-recovery properties, allowing it to slide back and forth within aluminum or plastic tracks without scratching them; when wrapped with special fabrics such as flexible steel mesh, only the outer webbing rubs against the surface, effectively protecting the curtain substrate.

[0022] IV. Excellent winding performance and not easily deformed. It eliminates the need for zippers and metal strips, has a soft overall texture, minimal springback during rewinding, and smooth winding without warping or deformation. It avoids the defects of hot-melt zippers that are prone to deformation during rewinding and T-shaped steel strips that can deform and get stuck in the track, which are irreversible.

[0023] V. Flexible selection and strong versatility. Different functional interlayer webbing can be replaced as needed; black plastic sheet achieves full light blocking, while transparent plastic sheet with transparent stitching achieves high light transmission; different narrow rails can be adapted simply by cutting the width of the plastic sheet, resulting in high production and modification efficiency.

[0024] VI. Customizable appearance and high added value. Patterns can be printed on both the plastic sheet and the interlayer webbing, allowing for personalized customization of the sealing strip.

[0025] VII. Continuous manufacturing process and straight finished product. The manufacturing method of this invention uses pre-punched holes combined with hot-melt coated sewing thread, followed by plasma activation, visual dispensing, and segmented temperature-controlled belt-type hot pressing to form a single piece. The hot-melt adhesive fills the holes and cures to form a mechanical lock, so that the sewing thread and plastic sheet are firmly bonded by hot-melt adhesive filling the holes rather than simply adhering to the surface. The finished product is straight and wrinkle-free throughout, with high durability, low failure rate, and no metal corrosion or fabric delamination problems. Attached Figure Description

[0026] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0027] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0028] Figure 2 This is a front view of the present invention;

[0029] Figure 3 This is a reverse side view of the invention;

[0030] Figure 4 This is a schematic diagram of folding the functional webbing in this invention;

[0031] Figure 5 This is a diagram showing the recycling status of rewindable products;

[0032] Figure 6 A schematic diagram showing how a sealing strip is welded onto fabric and snapped into a groove in a slide rail / round tube / pull beam;

[0033] Figure 7 This is a schematic diagram of the installation process for rewindable products.

[0034] Figure labels: 1. Sewing thread, 2. Plastic sheet, 3. Functional webbing, 4. Coated layer. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0036] The following is in conjunction with the appendix Figures 1 to 7 This invention provides a detailed description of the technical solutions offered in various embodiments. One embodiment of the invention provides a sandwich-type windproof sealing strip, such as... Figure 1 As shown, the device includes a sealing strip body, which has a long strip-shaped structure with a sandwich-like multi-layered cross-section along its length. The multi-layered structure consists of a central middle layer and side layers positioned above and below the middle layer. The middle layer is a hydrophobic thermoplastic sheet 2, and the side layers are double-sided adhesive-coated waterproof functional webbing 3. The plastic sheet 2, functional webbing 3, and functional webbing 3 are secured together along their length by a hot-melt adhesive-coated sewing thread 1. The sealing strip body has a groove at its mounting end, which mates with a rewinding aluminum profile. The groove depth matches the outer diameter of the rewinding tube. After installation, the sealing strip body is evenly wound and rolled up along the axis of the tube. The free end of the sealing strip body has a flat, straight edge, allowing it to slide smoothly in a plastic or aluminum guide rail.

[0037] Specifically, such as Figure 2 As shown, the sealing strip body consists of a lower functional webbing 3, a plastic sheet 2, and an upper functional webbing 3 along its width direction. The width of the upper and lower functional webbing 3 is greater than or equal to the width of the plastic sheet 2, so that the plastic sheet 2 is completely sandwiched and covered between the upper and lower functional webbing 3, with only the edges of the plastic sheet 2 and the functional webbing 3 exposed within the guide rail. A sewing thread 1 forms at least one stitch along the length of the sealing strip body, located within the width range of the plastic sheet 2. The sewing thread passes through and locks the upper and lower functional webbing 3 and the plastic sheet 2 at the stitch position, so that the three layers are combined into one at the stitch position while maintaining a layered structure on both sides of the stitch. The plastic sheet 2 is selected from hydrophobic thermoplastic materials such as polyethylene terephthalate, polypropylene, polyvinyl chloride, or thermoplastic polyurethane. It is inherently hydrophobic, and its surface does not easily absorb or retain moisture; at the same time, this type of material has a suitable elastic modulus, ranging from 0.15 mm to 2.0 mm. Within its thickness range, it can maintain stiffness along the length direction to withstand the side tension of the curtain, while also possessing flexibility and resilience when bending along the thickness direction. Thus, it can recover its straightness when winding and bending with the rewinding tube during the rewinding process, achieving deformation self-recovery.

[0038] The plastic sheet 2 has pre-punched holes evenly distributed along its length. The diameter of the pre-punched holes is smaller than the diameter of the sewing needle that accompanies the sewing thread 1. This interference fit between the hole diameter and the needle diameter is one of the key differences between this invention and existing sewing sealing solutions. In traditional sewing solutions, the needle hole pierced by the sewing needle on the fabric or plastic sheet is usually equal to or slightly larger than the needle diameter. An annular gap remains between the needle hole and the sewing thread, becoming a leakage channel for cold air penetration and rainwater backflow. In contrast, this invention pre-punches holes smaller than the needle diameter on the plastic sheet 2. When the sewing needle carrying the sewing thread 1 pierces the pre-punched hole, the hole wall is squeezed by the needle body and forms an interference contact with the needle body and the sewing thread 1. The sewing thread 1 is squeezed and positioned inside the hole, making it less prone to axial movement under repeated winding and sliding conditions. The diameter and spacing of the pre-punched holes are selected according to the thickness of the plastic sheet 2 and the diameter of the matching sewing needle. This ensures that the sewing needle can pass through smoothly during the piercing process and that the hot melt adhesive wrapped on the sewing thread 1 can be pressed into the holes in the subsequent hot pressing process. The pre-punched holes are pre-formed on the plastic sheet 2, avoiding tearing and positional drift of the hole edges caused by blindly piercing the non-perforated plastic sheet with the sewing needle. This ensures that the stitch of the sewing thread 1 is straight along its length and consistent with the hole position, providing a stable receiving cavity for the subsequent hot melt adhesive filling of the pre-punched holes to form a mechanical lock.

[0039] Furthermore, the pre-punched holes are circular holes evenly spaced along the length of the plastic sheet 2. The interference fit between the hole diameter and the diameter of the matching sewing needle is selected according to the elasticity of the plastic sheet 2 material and the diameter of the sewing thread 1, ensuring that the sewing needle can pierce smoothly and that the hole wall springs back to hold the sewing thread 1 tightly after piercing. The spacing between the pre-punched holes corresponds to the stitch length of the sewing machine, so that each stitch falls exactly into a pre-punched hole, avoiding blind piercing and tearing of the plastic sheet 2 by the needle falling into an area without holes. The pre-punched holes can be formed in one step by stamping or continuously formed by rolling, with smooth and burr-free hole edges, providing both a piercing guide for the sewing needle and a regular cavity for subsequent hot melt adhesive filling. Since the pre-punched holes are pre-formed before sewing, the sewing needle does not need to be drilled on the plastic sheet 2 itself, reducing sewing resistance and the risk of needle breakage, and improving the continuity of the sewing composite process and the straightness of the stitches.

[0040] The sewing thread 1 is pre-coated with hot melt adhesive. After the sewing is completed, the sealing strip body is fed into a segmented temperature-controlled hot pressing device. The high temperature in the hot pressing zone melts the hot melt adhesive coating on the outer layer of the sewing thread 1. The molten hot melt adhesive fills the pre-punched hole of the plastic sheet 2 at the needle hole due to capillary action and the pressure of the needle during piercing. Subsequently, it is cooled in a water-cooling zone, and the molten hot melt adhesive cools and solidifies in the pre-punched hole, forming a solid mechanical lock that interlocks the sewing thread 1 and the plastic sheet 2 within the hole. This mechanical lock not only firmly locks the sewing thread 1 to the plastic sheet 2, but also fills the original annular gap between the pre-punched hole and the sewing thread 1 with the solidified hot melt adhesive, fundamentally eliminating the leakage channel of the stitch hole, so that the sealing strip body maintains a continuous waterproof and windproof sealing interface along the stitch line where the sewing thread 1 is located. Unlike existing solutions that rely on the expansion of sewing thread when it gets wet to passively plug holes, the mechanical lock of this invention is actively formed by the melting, filling, and curing of hot melt adhesive. It does not depend on environmental moisture, and its volume is stable after curing. It will not re-expose leakage channels due to shrinkage in a dry environment, thus meeting both the requirements of light transmission and sealing.

[0041] Specifically, the multi-layer sandwich structure consists of an intermediate layer and side layers disposed at both ends of the intermediate layer. The intermediate layer is a hydrophobic thermoplastic sheet 2, and the side layers are double-sided adhesive-coated waterproof functional webbing 3. Figure 3 As shown, the functional webbing 3 has an adhesive layer 4 on both its upper and lower surfaces. The functional webbing 3 is clamped and limited on both sides of the plastic sheet 2 through a multi-layered sandwich structure. That is, the functional webbing 3 is not directly fused to the fabric or plastic sheet 2 by heat fusion welding, but is clamped and limited on both sides of the plastic sheet 2 by the clamping force formed by the thread 1 passing through and locking it. This clamping connection method avoids the defects of zipper teeth accumulating during rewinding and easily pulling the fabric / fabric wrinkling when opened again in the heat fusion solution, keeping the sealing strip body flexible overall. The adhesive layer 4 gives the surface of the functional webbing 3 hydrophobic and UV-blocking properties, preventing water and oil penetration and extending the outdoor service life of the sealing strip. Because the functional webbing 3 is assembled by clamping and limiting rather than permanent fusion, users can independently disassemble and replace the functional webbing 3 according to the usage scenario without damaging the rest of the sealing strip body structure.

[0042] The functional webbing 3 uses polyester woven fabric or warp-knitted fabric as the base material, and its upper and lower surfaces are coated with an adhesive layer 4. The adhesive layer 4 can be a polyurethane coating or a polyvinyl chloride coating, giving the functional webbing 3 hydrophobic, water and oil penetration-proof, and ultraviolet-proof properties. Depending on the different requirements for light blocking and heat insulation, the functional webbing 3 can be configured as a full-light-blocking webbing, a semi-light-blocking webbing, or a heat-insulating and UV-resistant webbing: the full-light-blocking webbing is woven with a high density and combined with an opaque coating to block light transmission; the semi-light-blocking webbing is woven with a moderate density, allowing some light to pass through softly; the heat-insulating and UV-resistant webbing has heat-insulating and UV-resistant components in the coating to reduce heat radiation transmission and delay webbing aging. Since the upper and lower functional webbing 3 are only clamped to both sides of the plastic sheet 2 by the clamping force formed by the sewing thread 1 passing through and locking, rather than being permanently fused to the plastic sheet 2 by heat fusion welding, users do not need to damage the load-bearing sealing body formed by the plastic sheet 2 and the sewing thread 1 when replacing the functional webbing 3. Thus, the same sealing strip body can be adapted to various usage scenarios such as full blackout, semi-blackout, waterproof and heat insulation.

[0043] Plastic sheet 2 is a hydrophobic thermoplastic flexible sheet material with flexibility and self-recovery properties. Its hydrophobicity prevents it from absorbing moisture; its soft texture prevents it from scratching the inner wall of aluminum or plastic guide rails during reciprocating sliding, and the plastic layer cushions the aluminum contact surface of the pull beam to eliminate metal-to-metal friction. Plastic sheet 2 has inherent self-recovery properties; after installation, the sealing strip is evenly wound and rolled up along the axis of the rewind tube. After repeated rewinding and bending, plastic sheet 2 can restore its straight shape, avoiding the defects of metal steel strips, which lack self-recovery ability after deformation and become unusable upon deformation. Compared to rigid zippers and metal steel strips, the soft texture of plastic sheet 2 results in less springback when the sealing strip is rewinded and bent, ensuring smooth winding without warping. For special breathable fabrics such as flexible steel mesh, after the plastic sheet 2 sandwich structure wraps the fabric, only the outer functional webbing 3 contacts and rubs against the guide rail, effectively protecting the curtain substrate.

[0044] Furthermore, the multi-layered sandwich structure composed of the flexible plastic sheet 2 and the upper and lower functional webbing 3 forms a continuous elastic filler between the side of the curtain and the guide rail. This filler can block and attenuate airflow and noise transmitted through the gaps on the side of the curtain, providing both sound insulation and heat insulation. The flat, straight edge of the free end of the sealing strip is smooth after cutting and polishing, resulting in low resistance and no jamming when sliding back and forth within the guide rail. Combined with the hydrophobic and soft properties of the plastic sheet 2, the sealing strip can slide smoothly without scratching the inner wall of the guide rail during long-term lifting and lowering use.

[0045] The slot is mounted on a small, rewinding aluminum tube. Thicker-walled, smaller-sized aluminum tubes can be used to improve the centrifugal stability of the roller blind during winding. Plastic sheet 2 can be cut to a narrower size to fit ultra-narrow guide rails, reducing the amount of aluminum material used in the tie beams and minimizing the overall installation space required for the sunshade.

[0046] The slot is located at the mounting end of the sealing strip body and extends along its length. The shape of the slot opening matches the outer edge of the rewinding round tube aluminum profile, and the depth of the slot matches the outer diameter of the rewinding round tube. This allows the sealing strip body to be securely mounted on the rewinding round tube and to be evenly wound and rolled up as the tube rotates, preventing it from coming off or misaligning. Because this invention uses a soft plastic sheet 2 interlayer instead of a rigid zipper and metal strip, both the rewinding round tube and the aluminum beam can be designed with narrow specifications and the tube wall can be thickened accordingly. This improves the rotational stiffness and winding stability of the roll without increasing the outer diameter of the profile. The width of the sealing strip body can be adjusted by cutting the width of the plastic sheet 2 and the corresponding width of the functional webbing 3 to fit different specifications of guide rails. For ultra-narrow guide rails, only the plastic sheet 2 and the functional webbing 3 need to be narrowed as a whole, without changing the mold or altering the overall structure, resulting in high production efficiency.

[0047] Example 1: Fully blackout sandwich-type windproof sealing strip. The middle layer is made of black hydrophobic thermoplastic sheet 2. The thickness of sheet 2 can be selected from 0.18 mm to 0.8 mm depending on the usage environment. The width is 5 to 25 mm depending on the sealing and rewinding requirements of different products. When used in thin and lightweight sunshades with ultra-narrow guide rails, the thickness of sheet 2 is set to the lower limit of 0.18 mm to minimize the thickness of the sealing strip body and the space occupied by rewinding. When used in regular-sized sunshades with moderate requirements for stiffness and durability, the thickness of sheet 2 is set to the median of 0.55 mm to balance flexible rewinding and structural stability. When used in large-format sunshades in strong outdoor wind conditions with high requirements for load-bearing capacity and deformation resistance, the thickness of sheet 2 is set to the upper limit of 0.8 mm to provide higher bending stiffness and rewinding stability. The plastic sheet 2 is covered with double-sided adhesive layer 4 on both the top and bottom sides by a full-light-blocking functional webbing 3. The black plastic sheet 2, together with the full-light-blocking functional webbing 3, has excellent light-blocking performance and meets the needs of indoor all-black sun shading.

[0048] In this invention, the thickness of the plastic sheet 2 is selected to be between 0.18 mm and 0.8 mm, and the width is 5 to 25 mm depending on the sealing and rewinding requirements of different products. When the thickness is less than 0.18 mm, the stiffness of the plastic sheet 2 along its length is insufficient, making it difficult to withstand the tension on the side of the curtain, and the interference grip of the pre-punched hole edge on the sewing thread 1 is weak. When the thickness is greater than 0.8 mm, the flexibility of the plastic sheet 2 along its thickness direction decreases, and the rebound amount increases when rewinding and bending, affecting smooth rewinding and increasing the space occupied by the rewinding of the sealing strip body. Therefore, the thickness of the plastic sheet 2 is limited to 0.18 mm to 0.8 mm to achieve a balance between stiffness and flexible rewinding. The lower limit of 0.18 mm is suitable for thin and lightweight applications and ultra-narrow guide rail scenarios, the median value of 0.55 mm is suitable for conventional size scenarios, and the upper limit of 0.8 mm is suitable for large-format applications and outdoor strong wind scenarios. The optimal value can be selected within this range according to the specific usage environment.

[0049] Example 2: High-transparency sandwich-type windproof sealing strip. The middle layer uses a transparent plastic sheet 2, paired with transparent hot-melt coated sewing thread 1, and the top and bottom sides are fitted with double-sided adhesive semi-transparent functional webbing 3. The fully transparent sheet material combined with the transparent sewing thread 1 minimizes visual obstruction and provides excellent light transmission, making it suitable for balconies, floor-to-ceiling windows, and other sunshade scenarios requiring light transmission. The width of the plastic sheet 2 can be cut according to the guide rail specifications. For ultra-narrow guide rails, only the plastic sheet 2 needs to be narrowed to fit, without changing the overall design, resulting in high production modification efficiency.

[0050] Example 3: Heat-insulating and UV-resistant sandwich-type windproof sealing strip. The middle layer is made of a 0.55 mm thick hydrophobic thermoplastic sheet 2, and the upper and lower sides are fitted with double-sided adhesive-coated heat-insulating and UV-resistant functional webbing 3. The adhesive layer 4 contains composite heat-insulating and UV-resistant components. This model is suitable for scenarios such as sunrooms and outdoor curtain wall shading that are subject to long-term sunlight and rain. The heat-insulating and UV-resistant properties of the functional webbing 3 reduce heat radiation transmission and extend the outdoor service life of the sealing strip. The hydrophobic and self-healing properties of the plastic sheet 2 ensure that it maintains its straightness and sealing performance after repeated rewinding and exposure to sun and rain.

[0051] To further illustrate the beneficial effects of the present invention, the following description is provided in conjunction with comparative examples.

[0052] Comparative Example 1 uses a traditional sewn-on sealing strip that directly sews a plastic sheet or webbing to the fabric. In this type of strip, the annular gap between the needle hole and the sewing thread at the point where the thread passes through is not filled, leading to air and water leakage along the stitch line under outdoor rain and strong winds. For breathable fabrics like mesh, the fabric surface easily separates from the sealing strip when stretched. In contrast to Comparative Example 1, this invention pre-punches holes smaller than the needle diameter on the plastic sheet 2, and then uses hot-melt-coated sewing thread 1 to fill the holes and solidify, forming a mechanical lock. This fills the annular gap at the stitch line, maintaining a continuous waterproof and windproof sealing interface along the stitch line, significantly improving the sealing performance.

[0053] Comparative Example 2 uses a zipper with a heat-fused sealing strip, where the zipper teeth are welded to the fabric. However, the zipper teeth tend to accumulate during rewinding, exhibiting significant springback that hinders the winding of the zipper tube. This leads to wrinkling of the fabric upon subsequent opening, and the heavy weight of the nylon-coated zipper causes fabric deformation due to thermal expansion and contraction, necessitating a larger outer diameter for the rewinding tube. In contrast, this invention replaces the rigid zipper with a soft plastic sheet 2 sandwich structure, and the functional webbing 3 is assembled using clamping and limiting rather than heat-fused welding. This maintains overall softness, minimizes springback during rewinding and bending, ensures smooth winding, and allows for narrower specifications of the rewinding tube and pull beam aluminum material, adapting to ultra-narrow guide rails.

[0054] Comparative Example 3 uses a metal strip sealing strip with a fabric-covered metal strip that is heat-fused to the fabric. The metal strip is hard and scratches the outer fabric and the inner wall of the guide rail when sliding back and forth within the guide rail. It is also prone to corrosion in humid environments. The adhesive on the fabric layer delaminates and splits after repeated bending and friction. Furthermore, the metal strip lacks self-recovery ability after deformation and becomes unusable upon deformation. In contrast to Comparative Example 3, this invention uses a hydrophobic, soft, and self-recovering plastic sheet 2 instead of the metal strip. It does not scratch the guide rail or tear the webbing during reciprocating sliding, avoids metal corrosion and fabric delamination issues, and can return to its straight shape after repeated rewinding and bending, significantly improving durability.

[0055] It should be noted that the functional webbing 3 comes in three specifications: full blackout, semi blackout, and heat insulation and UV protection. The webbing is independently detachable and detachable through interlayer clamping and limiting. Users can replace the corresponding functional webbing 3 according to different scenario needs such as full blackout, semi blackout, or waterproof and heat insulation without replacing the overall sealing strip. The surface of the plastic sheet 2 can also be printed with logos and decorative patterns to realize product personalization and enhance product added value.

[0056] like Figure 4 As shown, when connecting the sealing strip body to the fabric or material of the sunshade curtain, the functional webbing 3 is folded in half, and the fabric or material is placed inside the side of the functional webbing 3 with the adhesive layer 4. The folded edge is heated using a heat sealing device, so that the adhesive layer 4 at the folded edge melts and adheres to the fabric or material, forming a flat and firm edge binding structure. For fabrics, materials, or projection fabrics that cannot be directly heat-sealed, through holes can be punched in the area to be heat-sealed, so that the adhesive of the adhesive layer 4 on the inner side of the functional webbing 3 can penetrate through the through holes and be heat-sealed and locked with the fabric or material, achieving a firm bond.

[0057] The following describes the overall manufacturing process steps of the sandwich-type windproof sealing strip of the present invention.

[0058] The raw material pretreatment process includes the following three steps. First, processing of plastic sheet 2: Select thermoplastic raw materials that meet RoHS and REACH environmental standards, cut them to a standard thickness of 0.18 mm to 0.8 mm, and cut them to a width of 5~25 mm according to the sealing and rewinding requirements of different products. Punch pre-punched holes at equal intervals on the plastic sheet 2, with the hole diameter smaller than the diameter of the matching sewing needle. Black or transparent raw materials are selected as needed, and personalized plastic sheets 2 are pre-printed with graphics. Second, processing of functional webbing 3: Select blackout, semi-blackout, or heat-insulating fabric, and cut it into strips using 20 kHz ultrasonic equipment and a 120° cutting angle to achieve a burr-free and non-fraying webbing edge. After cutting, apply adhesive to both sides of the webbing to form a double-sided adhesive layer 4, resulting in a waterproof and UV-resistant functional webbing 3. Third, pretreatment of sewing thread 1: Select sewing thread 1 with polyester or polyurethane substrate, impregnate it with hot melt adhesive in a constant temperature environment of ±30 ℃, and let it stand at room temperature for 24 h after impregnation to allow the hot melt adhesive to fully crystallize and solidify, so as to obtain sewing thread 1 with uniform adhesive layer.

[0059] The sewing thread 1 is made of polyester or polyurethane substrate, taking into account both tensile strength and appropriate elongation to withstand the tension of the sealing strip body during sewing and rewinding. The sewing thread 1 is impregnated with hot melt adhesive in a constant temperature environment of ±30 ℃. The constant temperature impregnation ensures that the hot melt adhesive is evenly adhered to the surface of the sewing thread 1 and the adhesive layer thickness is consistent. After impregnation, it is left to stand at room temperature for 24 hours to allow the hot melt adhesive to fully crystallize and solidify, so as to avoid the adhesive layer becoming sticky and sticky in subsequent sewing processes, ensuring that the sewing thread 1 can be smoothly threaded and has a stable amount of meltable adhesive during hot pressing.

[0060] Regarding the selection of ultrasonic slitting frequency, the applicant compared four frequencies: 15 kHz, 20 kHz, 28 kHz, and 35 kHz. The energy of 15 kHz was too low, resulting in insufficient edge sealing. The energy of 28 kHz and 35 kHz was too high, which could easily cause the fabric edges to over-melt and clump together. Only 20 kHz, combined with a 120° cutting angle, could achieve the effect of sealing without fuzz and preventing fraying by hand. Therefore, 20 kHz was selected.

[0061] Layered sewing composite process: The lower layer of adhesive-coated functional webbing 3, the pre-punched plastic sheet 2, and the upper layer of adhesive-coated functional webbing 3 are stacked and aligned in sequence. The modified three-thread one-needle overlock machine is used to operate with a single thread. The overlock machine is equipped with an electronic drag wheel and a double-roller pressing helical gear drive structure at the rear end. The pre-treated hot-melt coated sewing thread 1 is used to pass through the three layers of materials to complete the sewing splicing. During the sewing process, the roller pressure limit is used to prevent the plastic sheet 2 and the functional webbing 3 from wrinkling.

[0062] The three-thread one-needle overlock machine used has been modified to operate with only a single thread, avoiding frequent changes between the top and bottom threads and improving processing efficiency. The electronic roller at the rear end is driven by helical gears and pressed by upper and lower double rollers. During the sewing process, it applies synchronous traction and roller pressure to the overlapping functional webbing 3 and plastic sheet 2, keeping the plastic sheet 2 and functional webbing 3 flat and aligned during the sewing process. This prevents wrinkling caused by the difference in elongation between the plastic sheet 2 and the fabric, and ensures the straightness of the semi-finished product after sewing and bonding.

[0063] Plasma activation pretreatment process: Plasma activation treatment is performed on the surface of the sewn semi-finished plastic sheet 2 to improve the adhesion of the plastic sheet 2 surface and prepare for subsequent hot pressing adhesive layer bonding; visual precision glue is applied to the pinhole positions to ensure that a certain amount of hot melt glue is filled into each pre-punched hole.

[0064] The thermoplastic sheet 2 has low surface energy and poor adhesion, making it difficult to bond firmly to hot melt adhesive directly. Plasma activation treatment introduces polar groups on the surface of the sheet 2 to enhance its surface activity and adhesion, preparing it for subsequent filling and bonding of hot melt adhesive on the surface of the sheet 2 and in the pre-punched holes. Visual precision dispensing uses visual positioning to fill each pre-punched hole with a fixed amount of hot melt adhesive, which, together with the hot melt adhesive wrapped around the sewing thread 1, ensures that the pre-punched holes are fully filled, avoiding defects such as incomplete filling and poor sealing due to insufficient adhesive from a single adhesive source.

[0065] The segmented temperature-controlled belt-driven hot pressing and shaping process: The semi-finished product is fed into a high-temperature resistant belt conveyor hot pressing device controlled by dual servo motors and speed sensors. The belt runs synchronously throughout the process to ensure a uniform feeding speed. The product is processed in three temperature-controlled sections. The first section is the hot pressing zone, where the temperature can be selected within the range of 160℃ to 180℃, with 170℃ being preferred. This allows the hot melt adhesive on the outer layer of the sewing thread 1 to melt and fill the pre-punched holes in the plastic sheet 2. If the temperature is set to the lower limit of 160℃, the melting and filling degree will be too low, and the filling of the holes will be insufficient. If the temperature is set to the upper limit of 180℃, the webbing and plastic sheet will be overheated, which will easily affect the flatness. Therefore, the median value of 170℃ is preferred. The middle section is the room temperature transition zone, where the product is initially shaped by standing at room temperature. The last section is the water cooling zone, where water cooling is rapid. After the hot melt adhesive cools and solidifies, it forms a solid interlocking buckle in the pre-punched holes, making the sewing thread 1, plastic sheet 2, and functional webbing 3 firmly bonded together. The finished product is straight and wrinkle-free.

[0066] In the segmented temperature-controlled belt-driven hot pressing and shaping process, the upper and lower belt-driven transmission structures apply uniform surface pressure to the semi-finished product. Combined with dual servo motors and speed sensors for real-time correction of the feeding line speed, this ensures consistent heating time and pressure throughout the entire length of the semi-finished product, preventing wrinkling and warping caused by localized overheating or uneven pressure. The initial hot pressing zone melts the hot melt adhesive and fills the pre-punched holes under pressure. The middle room-temperature transition zone relaxes the stress and stabilizes the shape of the initially formed adhesive. The final water-cooling zone rapidly solidifies and shapes the adhesive. These three sections are seamlessly connected, enabling continuous production of the sealing strip. The belts are made of high-temperature resistant material to withstand the high temperatures of the initial hot pressing zone and maintain dimensional stability.

[0067] Finishing process after molding: Cut and process the groove structure at one end of the sealing strip, and match the outer diameter of the rolled-up round tube; cut and grind the other end to form a flat straight edge, and put it into the warehouse after inspection and approval.

[0068] In use, the sandwich-type windproof sealing strip of this invention is fitted onto the rewind tube of the sunshade curtain via its mounting groove, and then evenly wound and rolled up along the axis of the tube. Its free end, with its flat, straight edge, slides into the guide rails on both sides of the sunshade curtain, reciprocating within the guide rails as the curtain rises and falls. Because the groove can be fitted with a thickened, small-sized rewind tube, the centrifugal stability of the curtain during winding is improved. Furthermore, because the plastic sheet 2 can be cut to the width of the guide rails, it can be adapted to ultra-narrow guide rails, reducing the amount of aluminum material used in the tie beams and minimizing the overall installation space occupied by the sunshade curtain.

[0069] like Figure 5 As shown, in the retracted state, the roll-up sunshade is wound and stored on the top roll-up tube. A pull beam connects to the bottom of the curtain, and sliding rails are installed on both sides of the curtain. The sealing strip is located between the side of the curtain and the sliding rails. Figure 6 As shown, the sealing strip body is welded and fixed to the fabric of the curtain body via its functional webbing 3, and its mounting end is engaged with the groove of the slide rail, rewind tube, or pull beam to achieve a stable fit between the sealing strip body and the profile; as Figure 7 As shown, in the installation section, the central flexible plastic sheet 2 is locked through the glued heat-fusible sewing thread 1 and the upper and lower layers of glued functional webbing 3 which can be sandwiched. The glued layer 4 of the functional webbing 3 is glued and locked to the fabric and material of the curtain body by heat fusion. The free end of the sealing strip body extends into the slide rail, and while blocking the air intake channel on the side of the curtain body, it slides smoothly with the curtain body as it rises and falls.

[0070] From a structural causal perspective, the various technical features of this invention progress along a causal chain: First, the diameter of the pre-punched hole is set to be smaller than the diameter of the sewing needle, so that the sewing needle forms an interference fit with the pre-punched hole when piercing, and the needle hole is transformed from a leakage channel into an interference-fit positioning cavity for the sewing thread 1; Second, the plastic sheet 2 is made of flexible thermoplastic sheet material, so that the edge of the hole where the interference fit is located has elastic rebound ability when the sewing needle pierces and the sealing strip body is rolled back and bent, inhibiting the hole edge from cracking due to interference and repeated bending; Third, since the plastic sheet 2 needs to be waterproof on the surface... While providing UV protection, the material cannot be hardened by hot-melt welding. Therefore, a double-sided adhesive-coated functional webbing 3 is sandwiched and clamped on both sides of the plastic sheet 2, providing surface functionality without introducing a hardened area. Furthermore, the clamping and limiting connection method allows the functional webbing 3 to be independently disassembled and replaced, and a single sealing strip can adapt to various scenarios such as full blackout, partial blackout, and heat insulation and UV protection. Finally, a transparent plastic sheet 2 is used in conjunction with transparent sewing thread 1, and the width of the plastic sheet 2 is cut according to the guide rail specifications to ensure sealing while achieving high light transmittance and compatibility with ultra-narrow guide rails.

[0071] In the high-transparency model, the middle layer uses a transparent plastic sheet 2 and the through-locking fastener uses a transparent sewing thread 1. The sealing strip body retains the sandwich interlayer sealing function while minimizing the visual obstruction of the sheet and stitches. Combined with the narrowed plastic sheet 2 and functional webbing 3, it can be adapted to ultra-narrow guide rails and meet the installation requirements of balconies, floor-to-ceiling windows and other scenarios with high lighting requirements, achieving a balance between sealing and light transmission.

[0072] In the heat-insulating and UV-resistant version, the adhesive layer 4 of the functional webbing 3 contains composite heat-insulating and UV-resistant components, which can reflect or absorb some solar radiation and block ultraviolet rays, reducing the heat radiation transmitted through the side of the curtain, while delaying the aging of the functional webbing 3 under long-term sunlight. The hydrophobicity of the plastic sheet 2 prevents it from retaining moisture and swelling after rain. Combined with its self-recovery deformation characteristics, this version can maintain its flat appearance and sealing performance for a long time under harsh outdoor conditions of sun and rain.

[0073] It should be further explained that the surfaces of both the plastic sheet 2 and the functional webbing 3 can be printed with markings, logos and decorative patterns: the plastic sheet 2 is printed with graphics before the punching and pre-punching process, and the functional webbing 3 is printed with graphics before the adhesive is applied. This enables the personalized customization of the sealing strip product, increases the added value of the product, and the printing process is independent of the sewing composite and hot pressing shaping process of the present invention and does not affect each other.

[0074] The sandwich-type windproof sealing strip of this invention does not contain any metal components, thus avoiding the corrosion problem of the metal steel strip solution. The upper and lower functional webbing 3 and the plastic sheet 2 are locked together by sewing thread 1 and sealed with hot melt adhesive, rather than being glued together. Therefore, it does not have the problem of delamination and edge opening caused by long-term repeated bending and friction in the metal steel strip wrapping solution. Under the alternating hot and cold environment, the layers of the sandwich structure are firmly bonded and not easy to delaminate and crack. Therefore, the finished product has a low after-sales repair rate and strong durability.

[0075] Furthermore, the sandwich-type windproof sealing strip of this invention is not only suitable for retractable sunshade curtains in home decoration, sunrooms and curtain wall exterior sunshade fields, but can also be applied to the side windproof sealing of other retractable sunshade products such as sliding curtains; its preparation method involves pre-punching combined with hot melt wrapped sewing thread, plasma activation, visual dispensing and segmented temperature-controlled belt hot pressing integral molding, the process is continuous and the parameters are controllable, suitable for large-scale continuous production.

[0076] In some embodiments, the sewing thread 1 is arranged with one or more stitches along the length of the sealing strip body, and the stitches are arranged side by side along the width of the plastic sheet 2, with each stitch landing on a pre-punched hole in the plastic sheet 2. The multiple stitches enhance the locking strength between the upper and lower functional webbing 3 and the plastic sheet 2, making it less likely for the three layers to separate when pulled by the side of the curtain; furthermore, they form multiple sealing lines in the width direction of the plastic sheet 2, which are filled and cured with hot melt adhesive, further improving the sealing reliability of the stitched area. The number and position of the stitches can be determined according to the width of the sealing strip body and the operating conditions.

[0077] In some embodiments, the diameter of the pre-punched holes has a moderate interference fit relative to the diameter of the sewing needle, so that the hole wall undergoes elastic deformation when the sewing needle punctures and rebounds to hold the sewing thread 1 tightly after the needle is withdrawn, while preventing the hole edge from tearing due to excessive interference fit during puncture. The hole spacing along the length direction of the pre-punched holes is consistent with the stitch length of the sewing machine, so that the sewing needle falls into the pre-punched holes one by one; if the hole spacing is too large, some stitches will fall into the non-hole area and blindly puncture the plastic sheet 2, while if the hole spacing is too small, it will weaken the continuous load-bearing area of ​​the plastic sheet 2 between adjacent pre-punched holes. Therefore, the hole spacing is selected according to the sewing needle length and the load-bearing requirements of the plastic sheet 2.

[0078] During the process of filling the pre-punched hole with hot melt adhesive to form a mechanical lock, the amount of hot melt adhesive should be such that it fills the annular gap between the pre-punched hole and the sewing thread 1, forming a continuous glue cap at both ends of the pre-punched hole. Insufficient filling will leave unfilled gaps in the pre-punched hole, creating a potential leakage risk. Excessive filling will form excess glue nodules on the surface of the plastic sheet 2, affecting the flatness and appearance of the sealing strip. Therefore, the filling amount is controlled by the hot melt adhesive wrapped around the sewing thread 1 itself and the hot melt adhesive added at the needle hole. The adhesive is then shaped and cured in the pre-punched hole by the subsequent water-cooling cooling zone, forming a stable mechanical lock.

[0079] The mounting end slot of the sealing strip body and the rewinding tube are fitted with a transition fit or an interference fit, ensuring that the sealing strip body moves synchronously with the rewinding tube during winding and unwinding without relative slippage. When the rewinding tube rotates to wind up, the sealing strip body wrapped around the tube is stacked layer by layer. The flexibility of the soft plastic sheet 2 ensures that the layers fit tightly together and occupy little radial space, thus allowing the use of a rewinding tube with a smaller outer diameter and a larger wall thickness. This reduces the outer diameter of the roll while improving its bending stiffness and rotational stability, and reduces vibration caused by changes in roll diameter during high-speed winding.

[0080] The free end of the sealing strip body is cut and polished to form a flat straight edge, which slides along the extension direction of the guide rail. The surface of the flat straight edge is free of burrs and protrusions after polishing. Combined with the soft and hydrophobic properties of the plastic sheet 2 and the functional webbing 3, the free end has low frictional resistance and does not get stuck when sliding back and forth in the guide rail, and avoids scratching and wear on the inner wall of the guide rail. The thickness of the free end is matched with the width of the guide rail groove, so that the sealing strip body can slide smoothly in the guide rail and be limited by the guide rail to prevent it from falling out when the curtain is subjected to lateral wind pressure, thereby blocking the air intake channel on the side of the curtain.

[0081] In the segmented temperature-controlled hot pressing and shaping process, the residence time of the semi-finished product in the hot pressing zone, the ambient temperature transition zone, and the water cooling zone is determined by the conveyor speed of the belt. The belt conveyor speed is driven by dual servo motors and corrected in real time by a speed sensor, ensuring that the residence time of the semi-finished product in each temperature zone is consistent throughout its entire length. The high-temperature section of the hot pressing zone allows the hot melt adhesive on the sewing thread 1 to fully melt and fill the pre-punched holes under the pressure of the belt surface. The ambient temperature transition zone allows the internal stress of the molten adhesive to relax, and the water cooling zone allows the adhesive to cool down and solidify rapidly. The three temperature zones are connected one after another and conveyed continuously, avoiding interruptions and waiting, improving production efficiency, and ensuring the consistency of the product's performance throughout its entire length.

[0082] The plasma activation treatment on the surface of the plastic sheet 2 after sewing can be carried out under normal or low pressure conditions. The plasma acts on the surface of the plastic sheet 2, introducing oxygen-containing polar groups and increasing the surface energy, thereby enhancing the adhesion between the hot melt adhesive filled in and the hot melt adhesive covered by the sewing thread 1 and the surface of the plastic sheet 2 and the wall of the pre-punched hole. This ensures that the mechanical lock after the hot melt adhesive fills and cures is firmly bonded to the plastic sheet 2 and will not loosen due to long-term use.

[0083] Before the interlayer sewing process, the lower functional webbing 3, the pre-punched plastic sheet 2, and the upper functional webbing 3 are stacked sequentially, aligning their edges with the stitch positions. After stacking, the double rollers and electronic rollers at the rear of the overlock machine provide synchronized traction tension, ensuring the three layers remain flat, aligned, and under consistent tension during sewing. Because the plastic sheet 2 and the functional webbing 3 have different materials and elongations, inconsistent tension or misalignment between layers can easily lead to wrinkles, misalignment, or stitches deviating from the pre-punched holes after sewing. Therefore, roller pressure limiting and tension synchronization control ensure the quality of the sewing process.

[0084] In the high-transmittance version, the refractive index of the selected transparent plastic sheet 2 and the transparent sewing thread 1 are similar, so that when light passes through the sealing strip body, the refraction and shift at the interface between the plastic sheet 2 and the sewing thread 1 is small, further reducing the visual visibility of the stitch line and making the overall visual interference of the sealing strip body less in the light-transmitting scene; at the same time, the transparent hot melt adhesive fills the pre-punched hole and cures, so as not to form obvious opaque spots at the stitch position, thus achieving good light transmission and appearance effect while ensuring sealing.

[0085] Before being put into storage, the formed sealing strip body undergoes quality inspection. Inspection items include, but are not limited to: the straightness of the entire length of the sealing strip body, the filling and sealing of the pre-punched holes at the stitch positions, the edge sealing of the functional webbing 3, and the fit between the installation end slot size and the outer diameter of the rewind tube. The qualified sealing strip body is then cut to the required length and stored for windproof sealing on both sides of rewind-type sunshade products such as rewind-type sunshades.

[0086] In other embodiments, the pre-punched holes on the plastic sheet 2 can be circular or oblong holes. The long axis of the oblong hole extends along the length of the sealing strip body to accommodate slight positional deviations in the length direction of the sewing stitch, improving the tolerance of the sewing needle falling into the pre-punched hole one by one. The groove at the mounting end of the sealing strip body can be a C-shaped clamping groove with its opening facing the rewinding tube. The C-shaped clamping groove clamps the outer edge of the rewinding tube with its opening and relies on the elastic rebound of the plastic sheet 2 to maintain the clamping force, facilitating the installation and removal of the sealing strip body. The above-mentioned variations in hole shape and groove form are all equivalent transformations within the scope of the present invention.

[0087] During the replacement of the functional webbing 3, since the upper and lower functional webbing 3 are clamped and limited on both sides of the plastic sheet 2 by a multi-layer sandwich structure, the original functional webbing 3 can be replaced with another specification of functional webbing 3 along the clamping edge formed by the sewing thread 1. The load-bearing sealing body composed of the plastic sheet 2, the sewing thread 1, and the pre-punched and filled mechanical locking buckle remains unchanged. As a result, users can quickly replace the corresponding functional webbing 3 on the same sealing strip body according to different scenario requirements such as full blackout, semi-blackout, or heat insulation and UV resistance, achieving multi-purpose use and reducing the types of spare parts and inventory costs in different scenarios.

[0088] In summary, this invention integrates connection and sealing at the same stitch position through a three-layer sandwich structure consisting of a pre-punched plastic sheet 2, a hot melt adhesive-coated sewing thread 1, and a double-sided adhesive-coated functional webbing 3, as well as a mechanical buckle formed by hot-pressing and melting the sewing thread 1 to fill the pre-punched holes and then curing it. This is achieved through a continuous process of plasma activation and segmented temperature-controlled belt hot pressing, taking into account multiple properties such as sealing and leak prevention, flexibility and self-healing, no damage to the track, adaptation to ultra-narrow guide rails, and functional reconfigurability.

[0089] The technical features described above in this invention are not simply superimposed, but rather are interconnected and synergistically linked by the concept of transforming the sewing needle hole from a leakage defect into a heat-fused locking cavity: the pre-punched hole, with a diameter smaller than the needle diameter, provides interference fit for needle puncture; the flexible thermoplastic sheet 2 provides elastic rebound at the hole edge to absorb puncture and roll-back stress; the heat-fused coated sewing thread 1, under heat pressure, presses molten adhesive into the pre-punched hole to solidify and form a mechanical lock, achieving both connection and sealing at the same stitch position; the double-sided adhesive-coated functional webbing 3 provides surface hydrophobicity and UV protection through clamping and limiting without introducing a hardened area, and can be independently replaced to adapt to various scenarios due to its clamping connection. Thus, the connection and sealing, which were mutually conflicting in existing solutions, are now integrated at the same needle hole position. The sealing strip body, while achieving a continuous waterproof and windproof sealing interface, maintains a flexible, self-healing, track-free, ultra-narrow, and reconfigurable comprehensive performance, resulting in an overall effect superior to the simple sum of the individual effects of each technical feature.

[0090] The above are merely embodiments of the present invention and are not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A sandwich-type windproof sealing strip, characterized in that, The sealing strip body is a long strip-shaped sealing strip body with a multi-layer sandwich structure. The multi-layer sandwich structure includes a central hydrophobic thermoplastic sheet (2) and a double-sided adhesive-coated waterproof functional webbing (3) placed on the upper layer of the plastic sheet (2). The plastic sheet (2) is a flexible sheet material with pre-punched holes with a diameter smaller than that of a sewing needle along its length. The upper functional webbing (3) and the plastic sheet (2) are locked together by a sewing thread (1) treated with hot melt adhesive. The sewing thread (1) is melted by hot pressing and filled with the pre-punched holes and then cured, forming a mechanical lock in the pre-punched holes that interlocks the sewing thread (1) and the plastic sheet (2). The mounting end of the sealing strip body is provided with a groove that cooperates with a rewinding tube. The cross-section of the free end of the sealing strip body is a flat straight edge that can slide in the guide rail.

2. The sandwich-type windproof sealing strip according to claim 1, characterized in that, The plastic sheet (2) is a flexible thermoplastic sheet. The diameter of the pre-punched hole is smaller than the diameter of the sewing needle that is matched with the sewing thread (1). When the sewing needle punctures, it forms an interference fit with the pre-punched hole.

3. The sandwich-type windproof sealing strip according to claim 1, characterized in that, The functional webbing (3) is clamped and limited on the upper and lower sides of the plastic sheet (2) by the multi-layer sandwich structure, and both sides of the functional webbing (3) are provided with adhesive layer (4).

4. The sandwich-type windproof sealing strip according to claim 3, characterized in that, The functional webbing (3) is a full-shade webbing, a semi-shade webbing, or a heat-insulating and UV-resistant webbing, and can be independently disassembled and replaced via the clamping and limiting mechanism.

5. The sandwich-type windproof sealing strip according to claim 1, characterized in that, The plastic sheet (2) is a transparent plastic sheet, and the sewing thread (1) is a polyester hot melt sewing thread. The width of the plastic sheet (2) is cut according to the guide rail specifications.

6. The sandwich-type windproof sealing strip according to claim 1, characterized in that, The thickness of the plastic sheet (2) is 0.15 mm to 2.0 mm.

7. A method for preparing a sandwich-type windproof sealing strip, used to prepare the sandwich-type windproof sealing strip as described in claim 1, characterized in that, Includes the following steps: A pre-punched hole with a diameter smaller than that of a sewing needle is set on a hydrophobic thermoplastic sheet (2); the sewing thread (1) is soaked in hot melt adhesive and cured to obtain a hot melt adhesive-coated sewing thread (1); the lower double-sided adhesive-coated functional webbing (3), the plastic sheet (2), and the upper double-sided adhesive-coated functional webbing (3) are stacked and aligned in sequence, and the hot melt adhesive-coated sewing thread (1) is used to pass through the two layers to complete the sewing composite; the surface of the sewing composite plastic sheet (2) is plasma activated, and hot melt adhesive is filled into the pre-punched hole; the semi-finished product is sent into a segmented temperature-controlled hot pressing equipment, and passes through the hot pressing zone, the room temperature transition zone and the water cooling zone in sequence, so that the hot melt adhesive on the sewing thread (1) is heated and melted and fills the pre-punched hole, and then cooled and cured in the pre-punched hole to form a mechanical lock.

8. The preparation method according to claim 7, characterized in that, The temperature of the hot pressing zone of the segmented temperature-controlled hot pressing equipment is 160 ℃ to 180 ℃, the normal temperature transition zone is a normal temperature transition zone, and the water cooling zone is a water cooling zone.

9. The preparation method according to claim 7, characterized in that, The functional webbing (3) is cut by ultrasonic slitting, with an ultrasonic frequency of 20 kHz and a slitting cutter angle of 120°.

10. The preparation method according to claim 7, characterized in that, The sewing thread (1) is immersed in hot melt adhesive in a constant temperature environment of ±30 ℃, and then left to stand at room temperature for 24 h to allow the hot melt adhesive to crystallize and solidify.

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