A pneumatic pressing device for woven shaped airways and a method of manufacturing the same

Abstract

The application discloses a woven forming airway pneumatic pressing device and a preparation method thereof, and aims to solve the problems of low durability and low sealing property of the device in the prior art. The device comprises a main body, a gas path interface assembly is arranged on one side of the main body, the main body comprises at least one airway structure and at least one air-permeable structure, the airway structure is connected with the air-permeable structure, the airway structure comprises a first composite layer and a second composite layer, the first composite layer and the second composite layer are oppositely arranged, and the inner surfaces of the first composite layer and the second composite layer form a closed airway inner cavity. The airway structure for inflation and deflation is directly formed in the main body, and the sealing connection of the airway and the gas path interface assembly is considered in the process of forming the air-tight structure, so that the durability and the sealing property of the device are improved.

Description

Technical Field

[0001] This invention relates to the field of flexible wearable textile equipment technology, and in particular to a pneumatic pressing device for a woven air channel and its preparation method. Background Technology

[0002] Wearable pneumatic compression devices are widely used in scenarios such as sports rehabilitation, tactile interaction, and software-driven applications. These devices typically consist of three structures: a support structure that covers the human body and provides shape constraint, an inflatable pneumatic chamber that generates the compression action, and an air interface for connecting to an external air source. The inflatable pneumatic chamber that generates the compression action may be made of knitted fabric; however, because knitted fabric is composed of interlocking coils and has an inherent porous structure, it is difficult to directly form an airtight chamber from the main body.

[0003] In related technologies, a combination of a knitted outer shell and an independent inner liner is used to solve the above problems. The independent inner liner is usually installed inside the knitted outer shell by insertion or partial fixation. The air passage interface needs to penetrate the outer shell and communicate with the inner liner while also ensuring a sealed connection. The above methods still have the following significant drawbacks: First, the inner liner and the knitted outer shell are mainly physically overlapped or in point contact, making it difficult to form a stable interface bond, resulting in low material fusion and thus reducing the durability of the device; Second, the air passage interface needs to penetrate the outer shell and be sealed to the inner liner, which often relies on mechanical clamping or adhesive bonding. The interface sealing structure is fragile. Under the condition of large deformation of flexible fabrics, stress concentration is prone to occur at the interface, which can lead to loosening, detachment, or micro-leakage, resulting in reduced sealing performance.

[0004] The above problems urgently need to be addressed.

[0005] The above background information does not imply that the applicant accepts it as prior art. Summary of the Invention

[0006] In view of this, the present invention overcomes the shortcomings of low durability and low sealing performance of related technologies. The purpose of the present invention is to provide a pneumatic pressing device with a braided air passage and its preparation method. By directly forming an air passage structure for inflation and deflation inside the main body, and taking into account the sealing connection between the air passage and the air interface component during the formation of the airtight structure, the durability and sealing performance of the device are improved.

[0007] The present invention provides a pneumatic pressing device with a braided airway, comprising a main body, an airway interface assembly on one side of the main body, the main body including at least one airway structure and at least one breathable structure, the airway structure being connected to the breathable structure, the airway structure including a first composite layer and a second composite layer, the first composite layer and the second composite layer being disposed opposite to each other, the inner surface of the first composite layer and the inner surface of the second composite layer forming a closed airway cavity. The first composite layer includes a first functional layer, on which a first skeleton layer is provided; the second composite layer includes a second functional layer, on which a second skeleton layer is provided; both the first functional layer and the second functional layer include first yarns; both the first skeleton layer and the second skeleton layer include second yarns; and the first yarns and the second yarns are woven together. The first yarn comprises thermoplastic polyurethane, and the second yarn has a higher melting point than the first yarn; The first yarn is hot-pressed with thermoplastic polyurethane to form an airtight barrier film.

[0008] Optionally, the airtight barrier membrane is embedded in the second yarn, and a physical interlocking bonding area is formed between the airtight barrier membrane and the second yarn. The thickness of the airtight barrier membrane is 0.1 mm to 0.5 mm.

[0009] Optionally, the gas passage interface assembly includes a flange base and a connecting nozzle. The flange base is embedded between the first composite layer and the second composite layer of the gas passage structure. The flange base is made of a thermoplastic material compatible with the gas-tight barrier membrane material. The flange base includes a flange plate, and the edge of the flange plate is synchronously fused and welded to the gas-tight barrier membrane. The connecting nozzle is fixedly connected to the flange base and passes through the body to connect to an external air source.

[0010] Optionally, the breathable structure includes a single-layer structure and / or a mesh structure, and the breathability of the breathable structure is not less than 150 L / (m²·s).

[0011] Optionally, the airway cavity is provided with a limiting connection structure, which is connected to the first yarn.

[0012] Optionally, the limiting connection structure is distributed in a dot matrix and / or linear pattern within the airway cavity.

[0013] Optionally, the second yarn includes a high-strength structural yarn with a specification of 100 denier to 300 denier and a breaking strength of not less than 4.0 cN / dtex.

[0014] Optionally, thermoplastic polyurethane accounts for 50% to 70% of the total denier of the first yarn.

[0015] Optionally, the first yarn includes a core-sheath structure, with thermoplastic polyurethane disposed in the sheath layer of the core-sheath structure, and the core layer material of the core-sheath structure including heat-resistant fibers.

[0016] Optionally, the first yarn includes a covering structure, wherein the covering layer of the covering structure includes thermoplastic polyurethane, and the core layer of the covering structure includes heat-resistant fiber.

[0017] The present invention provides a preparation method for a pneumatic pressing device of a braided formed air duct. The method includes the following steps: S1. Use a computerized knitting machine to integrally knit the main body according to a preset pattern, knitting to form a first composite layer and a second composite layer of the air duct structure, so that the first yarn is located on the relative inner surfaces of the first composite layer and the second composite layer, and the second yarn is located on the relative outer surfaces. At the same time, knit a limiting knotting structure in the inner cavity of the air duct, and knit a breathable structure at the edge of the air duct structure; S2. During the knitting process, place the flange base of the air circuit interface component between the first composite layer and the second composite layer at a preset interface position, and continue knitting to complete the edge sealing so that the flange base is embedded and positioned; S3. Introduce pressurized gas into the inner cavity of the air duct to prevent the relative inner surfaces of the first composite layer and the second composite layer from sticking during hot pressing; S4. Perform hot pressing treatment on the air duct structure and its peripheral sealing area, so that the thermoplastic polyurethane component in the first yarn melts and forms an airtight barrier film, and a physical interlocking bonding area is formed between the airtight barrier film and the second yarn. At the same time, a continuous sealed connection interface is formed between the flange base and the airtight barrier film, where the hot pressing temperature is Tprocess and satisfies Tm1 < Tprocess < Tm2; where, Tm1 is the melting point of the thermoplastic polyurethane component in the first yarn, and Tm2 is the upper temperature limit for the second yarn to maintain structural integrity under hot pressing conditions; S5. Cool and cure while maintaining the isolation assistance state to complete the preparation.

[0018] Optionally, the gas pressure introduced in step S3 is 0.1 MPa to 0.3 MPa.

[0019] Optionally, the hot pressing temperature in step S4 is 160 °C to 175 °C, the hot pressing pressure is 0.3 MPa to 0.8 MPa, and the pressure holding time is 20 s to 60 s.

[0020] Compared with the prior art, the beneficial effects of the present invention are: The interlocking bonding area of the present invention can reduce the risk of interface cracking, peeling or sealing boundary deterioration caused by relative interface slip and stress concentration under the condition of repeated deformation during cyclic charging and discharging of gas, thereby being beneficial to improving the airtight performance retention ability and structural durability. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0022] Figure 1 This is a schematic diagram of the structure of a pneumatic pressing device for a braided air passage according to this application.

[0023] Figure 2 This is a schematic diagram of the air passage structure of a pneumatic pressing device for a braided air passage before hot pressing, according to this application.

[0024] Figure 3 This is a schematic diagram of the air passage structure of a pneumatic pressing device with a braided air passage according to this application after hot pressing.

[0025] Figure 4 This application discloses a pneumatic pressing device for a braided air passage. Figure 2 Enlarged diagram of point A in the middle.

[0026] Figure 5 This application discloses a pneumatic pressing device for a braided air passage. Figure 3 Enlarged diagram of point B in the middle.

[0027] Figure 6 This is a schematic diagram of the knitted structure of the air passage of a pneumatic pressing device for a knitted air passage according to this application.

[0028] Figure 7 This is a partial cross-sectional view of the connection between the airway interface component and the airway structure of a pneumatic pressing device for a braided airway according to this application.

[0029] Figure 8 This is a schematic diagram of the process flow for preparing a pneumatic pressing device with a braided air passage according to this application.

[0030] Figure 9 This is a comparative schematic diagram of the cross-sectional microstructure of the airway structure under different hot pressing process parameters for a pneumatic pressing device for a braided airway according to this application.

[0031] Figure 10 This is a schematic diagram of the air-permeable structure of a pneumatic pressing device with a woven air passage according to this application.

[0032] Figure 11 This is a schematic diagram showing the contact pattern and pressure distribution of a pneumatic pressing device for a braided airway in the inflated state of a limited-position connection structure, according to the present application.

[0033] Figure 12 This is a schematic diagram showing the contact pattern and pressure distribution of a pneumatic pressing device with a braided airway according to this application in an inflated state with an unlimited connection structure.

[0034] Figure 13This is a schematic diagram of the fourth embodiment of a pneumatic pressing device for a braided airway according to this application.

[0035] In the picture: 1. Main body; 11. Air passage structure; 111. First composite layer; 112. Second composite layer; 113. First functional layer; 114. First skeleton layer; 115. Airtight barrier membrane; 116. Air passage inner cavity; 117. Edge sealing; 118. Limiting connection structure; 119. Second functional layer; 120. Second skeleton layer; 1101. First yarn; 1102. Second yarn; 12. Breathable structure; 121. Mesh structure; 122. Transition connection section; 2. Air passage interface assembly; 21. Flange base; 211. Flange; 212. Guide groove; 213. Rough texture; 22. Connecting nozzle; 3. Physical interlocking joint area. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0037] It should be noted that in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Similarly, words such as "a" or "one" do not indicate a quantity limitation, but rather indicate the presence of at least one; "multiple" indicates two or more. Unless otherwise stated, words such as "before," "after," "below," and / or "above" are for illustrative purposes only and are not limited to a location or spatial orientation.

[0038] In this application, the term "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0040] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0041] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0042] In related technologies, wearable pneumatic pressing devices are widely used in scenarios such as sports rehabilitation, tactile interaction, and software-driven applications. Such devices typically include three core modules: a support structure for covering the human body and providing shape constraints, an inflatable and deflated pneumatic chamber for generating pressing actions, and an airway interface for connecting to an external air source.

[0043] Because knitted fabrics are composed of interlocking loops and have an inherent porous structure, it is difficult to directly form an airtight chamber in the main body. Therefore, existing technologies mainly achieve airtightness through the following paths: First, the independent inner liner path: using thermoplastic films such as TPU to heat-seal an independent airbag, which is then inserted into the knitted outer shell; second, the overall coating / lamination path: applying a full-coverage coating or film to the fabric surface or interlayer; third, the fully formed knitted composite path: using a computerized flat knitting machine to knit a bag-like structure, but still requiring the above-mentioned inner liner or coating methods to achieve airtightness.

[0044] In related technologies, a combination of a knitted outer shell and an independent inner lining is used to solve the above problems. The independent inner lining is usually installed inside the knitted outer shell by insertion or partial fixation. The air passage interface needs to penetrate the outer shell and communicate with the inner lining while also ensuring a sealed connection. The above methods still have the following significant drawbacks: First, the structure is split and lacks material-level fusion: the airtight layer and the skeleton layer are mainly physically stacked or in point contact, making it difficult to form a stable interface bond. Under repeated inflation and deflation cycles, the two layers of material are prone to relative sliding and friction, leading to interface wear, wrinkling, or localized stress concentration, thus reducing the device's durability. Secondly, the manufacturing process is discrete and highly dependent on assembly: this solution typically requires multiple processes such as inner liner preparation, outer shell weaving, inner liner assembly and positioning, interface insertion and fixing, etc. The large number of heterogeneous interfaces and long process chain make it difficult to control manufacturing consistency and quality stability, and are not conducive to automated continuous production. Thirdly, the interface sealing structure is fragile: the air circuit interface needs to penetrate the outer shell and be sealed to the inner liner, often relying on mechanical clamping or adhesive bonding. Under the condition of large deformation of flexible fabric, stress concentration is prone to occur at the interface, which can lead to loosening, detachment, or micro-leakage, reducing the reliability of the seal. Fourthly, breathability and comfort are limited: if an overall coating / lamination method is used to enhance air tightness, although it can improve the leakage problem, it will significantly weaken or even lose the original breathability and moisture permeability of the fabric, resulting in a decrease in thermal and moisture comfort during long-term wear.

[0045] This invention utilizes zoned weaving and in-situ hot-pressing film-forming technology to create an air channel structure physically interlocked with the fiber skeleton within the fabric. This aims to solve problems such as weak interfacial bonding, complex assembly, and easy interface failure in traditional split-structure fabrics, while preserving the breathability and moisture permeability of the breathable structure. The zoned breathability relies on limiting the heated and compressed areas during hot pressing: the hot pressing coverage is limited to the air channel structure and its surrounding sealed area; the breathable structure does not participate in the densification hot pressing process, thus preventing the formation of a continuous dense layer of molten TPU within the breathable structure.

[0046] First Embodiment Please refer to Figures 1 to 12 The first embodiment of the present invention provides a pneumatic pressing device for woven air channels and its preparation method.

[0047] This invention provides a pneumatic pressing device with a braided airway, comprising a main body 1, an airway interface assembly 2 on one side of the main body 1, the main body 1 including at least one airway structure 11 and at least one breathable structure 12, the airway structure 11 being connected to the breathable structure 12, the airway structure 11 including a first composite layer 111 and a second composite layer 112, the first composite layer 111 and the second composite layer 112 being disposed opposite to each other, the inner surface of the first composite layer 111 and the inner surface of the second composite layer 112 forming a closed airway cavity 116; It is worth noting that the main body 1 is integrally formed using full-body knitting technology. In terms of macroscopic form, it can be a sleeve shape conforming to the shape of the human limb or a wrapped sheet shape; in terms of microscopic structure, it is formed by the interweaving of at least two types of yarns with different properties. The main body 1 is divided into an air passage structure 11 and a breathable structure 12 on the plane, taking into account both airtight pressure bearing and breathable comfort functional zones.

[0048] In addition, the enclosed inner cavity provides a sealed space for subsequent inflation.

[0049] In addition, the edges of the first composite layer 111 and the second fabric edge layer are sealed with full-needle interlacing, high-density weave, or other knitted sealing structures that can form a closed boundary for the double-layer structure, ultimately forming a double-layer bag-like or double-layer tubular shape. The first composite layer 111 is the side that touches the skin, and the second composite layer 112 is the side that contacts the outside.

[0050] The advantage of this design is that the knitted sealing structure achieves integrated edge sealing of the double-layer structure, improving the boundary sealing performance and structural integrity. The double-layer bag-like or tubular structure adapts to the mechanical shape requirements of inflation. The layered design of the skin-contact and outer side can be specifically optimized for the performance of different contact sides, taking into account both skin-contact experience and external damage resistance.

[0051] The first composite layer 111 includes a first functional layer 113, on which a first skeleton layer 114 is provided; the second composite layer 112 includes a second functional layer 119, on which a second skeleton layer 120 is provided; both the first functional layer 113 and the second functional layer 119 include a first yarn 1101; both the first skeleton layer 114 and the second skeleton layer 120 include a second yarn 1102; and the first yarn 1101 and the second yarn 1102 are woven together. It is worth noting that the first yarn 1101 is located on the relative inner surfaces of the first composite layer 111 and the second composite layer 112, and the second yarn 1102 is located on the relative outer surfaces of the first composite layer 111 and the second composite layer 112.

[0052] The advantage of this design is that the material-level bonding of the two-layer structure enhances the structural strength of the composite layer, avoids the risk of interlayer separation, and strengthens the overall mechanical properties and functional stability.

[0053] The first yarn 1101 comprises thermoplastic polyurethane, and the melting point of the second yarn 1102 is higher than that of the first yarn 1101. It is worth noting that the first yarn 1101 also ensures the airtightness of the device, while the second yarn 1102 is a supporting yarn that supports the structural framework of the device. The first yarn 1101 is one of thermoplastic polyurethane core-sheath composite yarn, thermoplastic polyurethane coated yarn, or multi-strand multifilament containing thermoplastic polyurethane.

[0054] The advantage of this setup is that the thermoplastic polyurethane component of the first yarn 1101 provides the material basis for the airtightness of the device, and the various yarn forms can be adapted to different weaving and usage requirements. The high melting point of the second yarn 1102 allows it to maintain structural integrity in the relevant processes of achieving the airtightness function of the first yarn 1101, and continuously play the supporting role of the structural skeleton.

[0055] Please refer to Figure 3 The first yarn 1101 is hot-pressed with thermoplastic polyurethane to form an airtight barrier film 115.

[0056] It is worth noting that the melting point of thermoplastic polyurethane is in the range of 120°C to 170°C, meaning it is a low-melting-point TPU component. The airtight barrier film 115 formed after hot pressing of the thermoplastic polyurethane is continuous and has a controllable thickness. The melting point of the thermoplastic polyurethane is denoted as Tm1. During hot pressing, the airtight barrier film 115 penetrates the second yarn 1102 to form a physically interlocked bonding region 3.

[0057] Furthermore, after the airway structure 11 is hot-pressed, the thermoplastic polyurethane in the inner wall functional layer melts, flows, and levels, forming a continuous embedded airtight barrier membrane 115 in situ. This airtight barrier membrane 115 and the first skeleton layer 114 are physically interlocked through melt penetration and inter-fiber bundle interlocking, rather than simple surface adhesion. The thickness of the airtight barrier membrane 115 is 0.1 mm to 0.5 mm. The airtight barrier membrane 115 is confined to the inner surface of the airway and, in cross-sectional microscopic observation, does not appear as a continuous, dense membrane layer extending to the outermost surface of the fabric, thus maintaining the appearance and feel of the outer side of the fabric. The physically interlocked bonding area 3, in cross-sectional observation, is characterized by the airtight barrier membrane 115 material entering the gaps between the fiber bundles of the first skeleton layer 114 and the second skeleton layer 120 to form a continuous or semi-continuous embedded interface, thus distinguishing it from a coating layer located only on the fabric surface.

[0058] The advantages of this setup are that the in-situ film formation process eliminates the bonding process of independent film layers, improving production efficiency; the physical interlocking combination greatly improves the bonding strength between the film layer and the skeleton layer, enhancing the fatigue resistance and service life of the device; the controllable thickness design ensures airtightness while maintaining the flexibility and wearability of the device; and the area limitation of the film layer preserves the appearance and feel characteristics of the main body 1.

[0059] Please refer to Figure 5The airtight barrier membrane 115 is embedded in the second yarn 1102, and a physical interlocking bonding area 3 is formed between the airtight barrier membrane 115 and the second yarn 1102. The thickness of the airtight barrier membrane 115 is 0.1 mm to 0.5 mm.

[0060] It is worth noting that the thickness of the airtight barrier membrane 115 is determined to be 0.1 mm to 0.5 mm according to cross-sectional microscopic measurements, and the airtight barrier membrane 115 does not penetrate to the outermost surface of the second yarn 1102 to maintain the appearance and feel of the fabric.

[0061] The advantage of this design is that limiting the thickness allows the membrane layer to achieve the optimal balance between density and flexibility. The physical interlocking bonding zone 3 eliminates the risk of membrane layer peeling and curling, improves the durability of the airtight structure, and prevents the membrane layer from penetrating to the outer surface, thus avoiding hardening of the fabric body and changes in appearance, which meets the usage requirements of flexible wearable products.

[0062] The gas passage interface assembly 2 includes a flange base 21 and a connecting nozzle 22. The flange base 21 is embedded between the first composite layer 111 and the second composite layer 112 of the gas passage structure 11. The flange base 21 is made of a thermoplastic material compatible with the material of the airtight barrier membrane 115. The flange base 21 includes a flange 211. The edge of the flange 211 is synchronously fused and welded to the airtight barrier membrane 115. A continuous and sealed connection interface is formed between the flange base 21 and the airtight barrier membrane 115. The connecting nozzle 22 is fixedly connected to the flange base 21 and passes through the body 1 to connect to an external air source.

[0063] It is worth noting that the flange base 21 uses the same or similar thermoplastic polyurethane material as the thermoplastic polyurethane in the inner wall functional layer to ensure synchronous fusion welding with the airtight barrier membrane 115 during hot pressing, forming a continuous sealed connection interface. This reduces the risk of microleakage and interface fatigue that may be introduced by adhesive or mechanical clamping connection methods. The connecting nozzle 22 is fixedly connected to the flange base 21 and extends through the fabric surface for connecting to an external air source. The connecting nozzle 22 can be a standard quick-connect fitting, threaded fitting, or other air connection interface to achieve connection and disconnection with an external air source or control system. The surface of the flange base 21 may be provided with guide grooves 212 and / or rough textures 213 to enhance its bonding strength with the surrounding yarns and the airtight barrier membrane 115. The flange base 21 has a diameter of 10mm to 20mm and a thickness of 0.5mm to 1.5mm, providing sufficient connection strength while avoiding excessive increase in local thickness and rigidity. The continuous sealing interface between the flange base 21 and the airtight barrier membrane 115 is characterized in cross-section as a sealing boundary where the two materials continuously transition or fuse, thus reducing the formation of micro-leakage paths. The vent hole of the connecting nozzle 22 communicates with the vent hole of the flange base 21, allowing the external air source to communicate with the inner cavity 116 of the air passage. The outer edge area of ​​the flange 211 of the flange base 21 is the main area where the sealing boundary is formed by synchronous fusion welding with the airtight barrier membrane 115. The protrusion position of the connecting nozzle 22 through the fabric surface corresponds to the pre-reserved structure in the weave, and a high-density weave area can be set around the protrusion to improve local tear resistance and stability.

[0064] In addition, the flange base 21 is provided with a flow guide groove 212 or a rough texture 213 on its surface to enhance its bonding strength with the surrounding yarns and the airtight barrier membrane 115.

[0065] The advantages of this setup are that synchronous fusion welding achieves material-level sealing between the interface and the airtight layer, fundamentally solving the problems of microleakage and interface fatigue. The embedded design of the flange base 21 enhances the bonding strength between the interface and the main body 1, preventing the interface from becoming a weak point in the structure. The surface texture design further strengthens the bonding strength, and the limited size balances the connection strength and local flexibility. Multiple interface forms improve the compatibility of the product with external equipment. The braided reserved structure and high-density organization area enhance the structural stability of the interface protrusion position, preventing tearing and damage during use.

[0066] The breathable structure 12 includes a single-layer structure and / or a mesh structure 121, and the air permeability of the breathable structure 12 is not less than 150 L / (m²·s).

[0067] It is worth noting that in the breathable structure 12, the first composite layer 111 and the second composite layer 112 are bonded together through a tucked or interlaced weave to form a single-layer structure or a mesh structure 121. Since this area is not subjected to a densification heat-pressing treatment, the yarns maintain gaps between knitted loops, allowing air and moisture to pass through to provide thermal and moisture comfort. The breathable structure 12 in the device serves to: maintain the structural continuity between the airway structure 11 and the breathable structure 12, reducing the risk of localized stress concentration; provide a heat and moisture transfer channel to reduce the formation of a moist microenvironment on the skin side; and provide a certain degree of elastic recovery to adapt to different limb sizes and dynamic deformation. The breathable structure 12 is woven using a mesh structure 121 or a diamond mesh structure 121. The lower limit of 150 L / (m²·s) for air permeability is determined with reference to the air permeability requirements for comfort fabrics in GB / T5453-1997 "Determination of Air Permeability of Textile Fabrics" and in conjunction with the basic needs of human skin's thermal and moisture regulation. This value ensures that the breathable fabric structure 12 has sufficient heat and moisture transfer capacity, reducing the risk of a moist microenvironment on the skin side and contributing to thermal and moisture comfort during prolonged wear. Below this value, the fabric's breathability may not be sufficient to meet the comfort requirements for continuous wear for more than 2 hours. This zoning strategy concentrates the airtight pressure-bearing function in the air channel structure 11, while avoiding the formation of a continuous dense layer in the breathable structure 12, thus structurally differentiating it from full-coverage films or monolithic coating / laminar solutions.

[0068] During the preparation process, the breathable structure 12 is limited by the hot-pressing area and does not participate in the densification hot-pressing treatment, thereby maintaining the gap between the knitted loops. Among them, the single-layer structure is the most basic planar knitted structure in all-weave knitting. It is formed by continuous knitting of a single loop structure to form a non-porous dense knitted layer without additional openwork, floats or tuck structures. Its loops are arranged in a regular interlocking state. After knitting, the resulting base fabric has a smooth surface and a dense structure, with good continuity and integrity. The mesh structure 121 is based on the single-layer knitted structure. Through the combined application of knitting techniques such as tuck, floats, and transfer, the knitted base fabric forms a regular and controllable openwork mesh structure. The size, shape and distribution of the mesh can be precisely controlled by knitting process parameters. The mesh is supported by continuous loop pillars or loop arcs, and the overall structure is porous, lightweight and has a certain degree of elasticity and mechanical support.

[0069] The advantages of this setup are that non-densification hot pressing simplifies the manufacturing process and reduces production energy consumption; the structural continuity design improves the overall mechanical performance of the device and reduces structural damage caused by stress concentration; the elastic recovery capability improves the product's adaptability and dynamic wearing experience; and the zoning strategy significantly improves wearing comfort compared to full-coverage film or coating solutions, while reducing material and process costs.

[0070] Please refer to Figure 6The airway cavity 116 is provided with a limiting connection structure 118, which is connected to the first yarn 1101.

[0071] It is worth noting that the main function of the limiting connection structure 118 is to control the maximum thickness of the airway after inflation, so that the airway cross-section remains flat or nearly flat, thereby increasing the effective contact area with the limb and improving the uniformity of compression output. By constraining the expansion thickness and cross-sectional shape, the limiting connection structure 118 can increase the effective contact area and improve the uniformity and fit stability of compression output.

[0072] Furthermore, the limiting joint structure 118 contains high-strength yarn and does not contain TPU. If it contains TPU, the limiting joint structure 118 will melt and generate viscous liquid during hot pressing, which will stick the two layers of fabric together, thus failing to achieve the functions of limiting expansion and maintaining flatness.

[0073] The limiting connection structure 118 is distributed in a dot matrix and / or linear pattern within the airway cavity 116.

[0074] It is worth noting that the dot matrix distribution is preferably arranged regularly, with a dot matrix spacing of 8 mm to 15 mm, in order to achieve a balance between limiting the expansion thickness and maintaining the fabric's softness. The linear distribution can be provided with one or more limiting lines along the length or width of the airway, forming a segmented airway structure 11.

[0075] The advantage of this design is that the connection between the limiting connection structure 118 and the first yarn 1101 enables them to be integrally formed with the airway body 1, improving structural rigidity, preventing detachment or deformation during use, effectively improving the effectiveness and uniformity of the pressing action, and enhancing the performance of the device.

[0076] The second yarn 1102 includes a high-strength structural yarn with a specification of 100 denier to 300 denier and a breaking strength of not less than 4.0 cN / dtex.

[0077] It is worth noting that high-strength structural yarns include, but are not limited to, high-strength polyester filaments or nylon 66 filaments, which play a role in supporting the mechanical strength of the yarn and ensuring the performance of weaving and processing. Their melting point or heat distortion temperature is denoted as Tm2, ​​and satisfies Tm2>Tm1.

[0078] In addition, the first and second skeleton layers maintain structural integrity during the hot pressing process, withstand the expansion stress generated by the air pressure inside the air passage during the use of the device and limit excessive expansion, while providing structural support for the airtight barrier membrane 115, so that it forms a physical interlocking bonding area 3 with the skeleton layer.

[0079] The aforementioned strength requirements are used to ensure that the first skeleton layer 114 and the second skeleton layer 120 can withstand the expansion stress caused by the internal pressure of the airway and to provide mechanical constraints on the airway morphology.

[0080] Denier is a commonly used non-statutory unit of measurement for fiber linear density. Its core function is to describe the fineness of a fiber. It is defined as the mass in grams of a 9000-meter-long fiber. That is, when the mass of a 9000-meter-long fiber is N grams, the linear density of that fiber is N denier. The calculation formula can be simply expressed as: Denier (D) = (fiber mass in g) ÷ (fiber length in m) × 9000. The core of the calculation is to reflect the fineness of the fiber through its mass at a fixed length.

[0081] The advantage of this setup is that the selected high-strength structural yarn provides sufficient mechanical support and anti-expansion capability for the device, ensuring the stability of the air passage shape. The appropriate linear density and breaking strength take into account the smoothness of the weaving process and reduce yarn loss during production.

[0082] Thermoplastic polyurethane accounts for 50% to 70% of the total denier of the first yarn 1101.

[0083] It is worth noting that this ratio range is used to form a continuous, airtight barrier film 115 after subsequent hot pressing: when the proportion of thermoplastic polyurethane is too low, it is difficult to form a continuous and dense film layer after melting; when the proportion of thermoplastic polyurethane is too high, the mechanical properties and processing properties of the composite yarn decrease, and there may be risks of yarn breakage or deformation during weaving.

[0084] The advantage of this setting is that this ratio range achieves the optimal balance between film-forming performance and overall yarn performance, ensuring the one-time forming rate of hot-pressed film, improving production efficiency, while maintaining sufficient mechanical strength and weaving adaptability of the yarn, reducing the process defect rate during production, and reducing product rework costs.

[0085] Please refer to Figure 4 The first yarn 1101 includes a core-sheath structure, with thermoplastic polyurethane disposed in the sheath layer of the core-sheath structure, and the core layer material of the core-sheath structure including heat-resistant fibers.

[0086] It is worth noting that the core-sheath structure is a concentric cylindrical layered structure, consisting of a core layer and a sheath layer. The material components of the core layer and the sheath layer are clearly defined in space and are integrally formed through melt co-spinning or composite spinning processes.

[0087] The core layer is usually made of heat-resistant fibers, such as polyester filament or nylon filament, which plays a role in supporting the mechanical strength of the yarn and ensuring the performance of weaving and processing. The outer layer is wrapped around the core layer so that the thermoplastic polyurethane in the outer layer can fully melt and flow during subsequent hot pressing, fill the gaps between the fabric loops and form an airtight barrier film 115.

[0088] The advantage of this design is that the core-sheath integrated molding process ensures the integrity and stability of the yarn structure, the functional partitioning of the core and sheath allows a single yarn to simultaneously bear mechanical support and film-forming function, improving the integrated utilization efficiency of materials, and the position design of the sheath allows the TPU to melt and flow more closely to the inner surface of the air passage during hot pressing, improving the accuracy and efficiency of film formation.

[0089] Please refer to Figure 9 This invention provides a method for preparing a pneumatic pressing device with a woven air passage. This method is based on a process of in-situ fusion sealing of fully woven knitted fabric and thermoplastic TPU material, achieving an airtight seal of the air passage inside the main body 1, and achieving a sealed integrated connection between the air passage interface and the main body 1 during the film-forming process. The method includes the following steps: S1. Using a computerized knitting machine, the main body 1 is knitted in an integrated manner according to a preset pattern. The knitting forms the first composite layer 111 and the second composite layer 112 on the air passage structure 11, so that the first yarn 1101 is located on the relative inner surface of the first composite layer 111 and the second composite layer 112, and the second yarn 1102 is located on the relative outer surface. At the same time, a limiting connection structure 118 is knitted in the air passage cavity 116, and a breathable structure 12 is knitted at the edge of the air passage structure 11. It is worth noting that the airway structure 11 is provided with a double-layer bag-shaped or tubular jacquard structure, which forms a first composite layer 111 and a second composite layer 112 arranged opposite to each other, and forms a closed inner cavity at the periphery through the sealing edge 117 structure.

[0090] In addition, the preferred machine size for computerized knitting machines is 10-18.

[0091] The advantage of this setup is that the selected computerized knitting machine ensures knitting precision and product quality, while the integrated knitting process enables the one-time forming of multiple structural and multifunctional areas, significantly shortening production steps, improving production efficiency, and reducing the risk of structural damage and precision deviation caused by multi-process processing.

[0092] S2. During the weaving process, the flange base 21 of the gas interface assembly 2 is placed between the first composite layer 111 and the second composite layer 112 at the preset interface position, and the weaving continues to complete the sealing edge 117 so that the flange base 21 is embedded and positioned. It should be noted that when knitting reaches the preset interface position, the knitting is paused, and the flange base 21 of the air passage interface component 2 is placed between the first composite layer 111 and the second composite layer 112; when placing, the flow guiding grooves 212 and / or rough textures 213 on the surface of the flange base 21 face the inner wall of the air passage, so as to fully contact with the molten TPU component during the subsequent hot pressing and film forming process and form a sealed connection interface. After the flange base 21 is placed, continue knitting to complete the edge sealing 117, so that the flange base 21 is embedded inside the fabric and兼顾 preliminary positioning. After the flange base 21 is placed, the flange plate 211 should be arranged to abut against the inner wall functional layer area at the predetermined sealing boundary of the air passage structure 11, so as to ensure that the molten TPU component can cover the outer edge of the flange plate 211 and form a continuous sealed connection interface during the subsequent hot pressing and film forming.

[0093] The advantage of such a setting is that the placement and embedding positioning during the knitting process realize the integrated combination of the interface and the main body 1, improve the structural integrity, and the directional placement and abutting arrangement provide an accurate structural basis for the subsequent hot pressing and sealing, improve the one-time forming rate of the interface seal, and avoid the sealing risk and structural damage caused by subsequent secondary processing.

[0094] S3. Inject pressurized gas into the air passage lumen 116 to prevent the relative inner surfaces of the first composite layer 111 and the second composite layer 112 from adhering during hot pressing; It should be noted that in addition to the method of injecting pressurized gas, a high-temperature resistant solid isolation layer can also be预置 in the air passage lumen 116. When using the high-temperature resistant solid isolation layer, the solid isolation layer is a polytetrafluoroethylene strip or a polytetrafluoroethylene sheet, and the solid isolation layer is抽出 through the reserved opening after step S4 is completed.

[0095] The advantage of such a setting is that the two isolation methods provide flexible process options for production, adapt to different production conditions and product requirements, effectively avoid the problem of interlayer adhesion in the hot pressing process, improve the product forming quality, reduce the process defect rate, the solid isolation layer can be recycled, and reduce the production material cost.

[0096] S4. Perform hot pressing treatment on the air passage structure 11 and its peripheral sealing area, so that the thermoplastic polyurethane component in the first yarn 1101 melts and forms an airtight barrier film 115, and a physical interlocking bonding area 3 is formed between the airtight barrier film 115 and the second yarn 1102, and at the same time a continuous sealed connection interface is formed between the flange base 21 and the airtight barrier film 115, where the hot pressing temperature is Tprocess and satisfies Tm1 < Tprocess < Tm2; where, Tm1 is the melting point of the thermoplastic polyurethane component in the first yarn 1101, and Tm2 is the upper temperature limit for the second yarn 1102 to maintain structural integrity under hot pressing conditions; It should be noted that when Tm1 < Tprocess < Tm2, the TPU component melts and flows to fill the gaps between the knitted coils, and a continuous airtight barrier film 115 is formed in situ on the inner surface of the air passage. Considering process stability, it is recommended that Tprocess be at least 10°C higher than Tm1 to ensure sufficient melting of the TPU, and at least 30°C lower than Tm2 to ensure the stability of the skeleton layer structure. When the Tm1 of the selected TPU component in the embodiment is about 150°C, the preferred range of Tprocess is 160°C - 175°C; when the selected Tm1 of the TPU component is higher or lower, Tprocess should be adjusted accordingly. This temperature window is used to achieve selective melting: the TPU component in the inner wall functional layer melts and flows sufficiently, while the first skeleton layer 114 and the second skeleton layer 120 maintain their structural integrity and avoid significant thermal deformation or melting.

[0097] In addition, the hot pressing area should at least cover the air passage structure 11 and its peripheral edge sealing 117, so that the molten TPU component synchronously fills the gaps between the coils of the peripheral edge sealing 117 and cools and solidifies to form a continuous sealing boundary, so as to reduce the risk of gas leakage along the pores of the peripheral tissue. When the flange base 21 is pre-set in the air passage structure 11, the hot pressing coverage area should also cover the area where the outer edge of the flange 211 is located, so that the outer edge of the flange 211 and the forming airtight barrier film 115 are synchronously melt-welded to form a continuous sealing boundary. The hot pressing coverage area is preferably limited to the air passage structure 11 and its peripheral sealing area, and the main body 1 of the breathable structure 12, the breathable tissue area, is avoided to be covered, so as to prevent the breathable structure 12 from being densified and reducing the breathable performance.

[0098] The advantage of such a setting is that the precise temperature window realizes selective melting in a single hot pressing process, synchronously completes the formation of the airtight layer, the physical interlocking between layers and the interface sealing, realizes the integration of multiple process objectives, greatly improves the production efficiency, and the precise limitation of the hot pressing area ensures the airtight function while retaining the original performance of the breathable structure 12, avoids the negative impact of the process on the non-target area, and improves the comprehensive performance of the product.

[0099] S5. Cool and solidify while maintaining the isolation assistance state to complete the preparation.

[0100] It should be noted that the fabric is cooled while maintaining the internal air pressure isolation or solid isolation state until the TPU component is solidified, preferably cooled to below 60°C to complete the shaping of the airtight barrier film 115. The cooling process should avoid the internal stress concentration and structural defects caused by rapid cooling; cooling while maintaining the expanded state can make the airtight barrier film 115 solidify in a relatively stable form.

[0101] Depending on the application requirements, post-processing can be performed, including antibacterial treatment, hydrophilic treatment, softening treatment, or odor suppression treatment; post-processing should avoid damaging or degrading the airtight barrier membrane 115. Finally, install the external air pipe connector or quick-connect connector to complete the device preparation, and ensure a tight connection with the connecting nozzle 22 to prevent air leakage.

[0102] The advantages of this setup are that maintaining isolation during cooling ensures the forming shape and dimensional accuracy of the airtight membrane layer, slow cooling reduces internal stress in the membrane layer, improves the structural stability and durability of the membrane layer, optional post-processing enriches product functions, increases product added value, and does not affect the core airtight performance, and the final joint installation enables rapid product forming and usage adaptation.

[0103] The gas pressure introduced in step S3 is 0.1 MPa to 0.3 MPa.

[0104] It is worth noting that a pressure regulating valve / relief valve and a pressure gauge or pressure sensor are preferably used to monitor and dynamically adjust the internal pressure of the air passage, so that the pressure is kept within the preset pressure window throughout the hot pressing process, thereby stabilizing the open state and reducing the risk of adhesion and uneven film thickness. The selection of the gas pressure range takes into account the following factors: First, the lower pressure limit of 0.1 MPa should be sufficient to overcome the weight of the fabric and the external pressure during the hot pressing process, so as to keep the air passage open; second, the upper pressure limit of 0.3 MPa should avoid excessive expansion of the air passage, which may cause the hot pressing mold to fail to press effectively or the limiting connection structure 118 to be subjected to excessive force.

[0105] The advantage of this setting is that selecting a pressure range ensures the stability of the air channel opening state, providing a basis for uniform film formation. Dynamic pressure adjustment enables precise pressure control throughout the hot pressing process, significantly reducing process defects such as interlayer adhesion and uneven film thickness, improving product yield, and avoiding structural damage and mold compatibility issues caused by excessive air channel expansion.

[0106] In step S4, the hot pressing temperature is 160°C to 175°C, the hot pressing pressure is 0.3MPa to 0.8MPa, and the holding time is 20s to 60s.

[0107] It is worth noting that the hot-pressing pressure range is 0.3 MPa to 0.8 MPa. This pressure range is used to ensure that the molten TPU flows sufficiently and penetrates into the gaps between the fiber bundles, while avoiding excessive pressure that could cause the fabric structure to collapse or the yarn to be damaged. Under this pressure, the molten TPU component penetrates and intercalates into the second yarn 1102, forming a physically interlocked bonding zone 3.

[0108] In addition, when the gas pressure is 0.1 MPa to 0.3 MPa and the hot pressing external pressure is 0.3 to 0.8 MPa, the inner surface of the air passage can be in full contact with the molten TPU components under controlled pressure, which is beneficial for uniform film formation.

[0109] Additionally, the holding time should range from 20 to 60 seconds. Too short a holding time may result in insufficient TPU leveling and uneven film thickness; too long a holding time and excessive pressure may cause excessive TPU flow and penetration to the outer surface of the fabric, affecting appearance and feel. Excessive penetration refers to the molten TPU penetrating the first skeleton layer 114 and the second skeleton layer 120, forming a visually visible glossy film on the outermost surface of the fabric, or causing the fabric to feel noticeably harder. The method for determining this is to visually inspect the outer surface of the fabric after hot pressing; there should be no abnormal gloss or stickiness; the fabric's softness should not change significantly upon touch inspection. Process adjustments to avoid excessive penetration include: reducing the hot pressing temperature, shortening the holding time, and reducing the hot pressing pressure, while ensuring film formation.

[0110] The advantage of this setup is that it ensures the airtightness of the membrane layer and the strength of the interlayer bonding. The combination of internal and external pressure makes the membrane layer formation more uniform and improves the airtightness. The limitation of the parameter range ensures the quality of film formation while avoiding damage to the fabric structure and excessive penetration of TPU, thus ensuring the appearance and feel of the product and reducing the complexity of process adjustment.

[0111] The following are the methods for determining various parameters in this application: (1) Determination of Tm1 and Tm2: Tm1 is the melting point of the TPU component in the first yarn 1101, determined by differential scanning calorimetry (DSC), with the peak temperature of the endothermic peak as the melting point value; Tm2 is the upper limit of the temperature at which the second yarn 1102 maintains structural integrity under the hot pressing conditions of this application. The criteria for determining structural integrity are as follows: under hot pressing pressure of 0.3-0.8 MPa and holding time of 20-60 seconds, the skeleton yarn does not exhibit any of the following phenomena: firstly, the heat shrinkage rate exceeds 5% as determined by GB / T6505; secondly, visually visible adhesion or fusion occurs between adjacent yarns; thirdly, the breaking strength retention rate of the yarn before and after hot pressing is less than 90% as determined by GB / T3916.

[0112] (2) Determination of air permeability: The air permeability of the air-permeable structure 12 was determined according to GB / T5453-1997 "Determination of air permeability of textile fabrics". The test pressure difference was 200Pa, and the air flow rate per unit area per unit time was measured and expressed as L / (m²·s).

[0113] (3) Samples are taken from the airway structure 11 and cross-sections are prepared. Cutting can be done with a blade or by freezing. The thickness of the airtight barrier membrane 115 is measured at no fewer than 5 locations using an optical microscope or scanning electron microscope (SEM). The average value is taken, and the maximum and minimum values ​​are recorded. The membrane thickness is affected by factors such as the TPU component ratio, hot-pressing pressure, holding time, and the state of the barrier membrane. During the process, the membrane thickness and uniformity can be controlled by adjusting the above process parameters.

[0114] (4) Definition and determination method of physical interlocking region 3: The physical interlocking bonding area 3 refers to the composite interface area formed by the airtight barrier membrane 115 material penetrating into the direction of the first skeleton layer 114 and the second skeleton layer 120 during the hot pressing film formation process, and embedding into the gap of the second yarn 1102 after curing. The interface is characterized by the interlocking, wrapping or filling of the yarn by the membrane material.

[0115] The determination method for cross-sectional microscopic observation is as follows: a) Sample preparation: Take a sample from the airway structure 11 and prepare a cross-sectional sample along the direction perpendicular to the fabric surface. This can be done by embedding the sample in epoxy resin and then grinding and polishing or by cryosectioning. b) Observation method: The cross-sectional morphology was observed using a scanning electron microscope (SEM) at a magnification of 100 to 500 times; c) Judgment criteria: In cross-sectional observation, it can be observed that the airtight barrier membrane 115 penetrates from the inner surface of the air passage into the gap of the second yarn 1102, forming a continuous or semi-continuous embedded interface; the penetration depth is not less than 50μm, or the morphological characteristics of the membrane material wrapping and filling the gap of the fiber bundle can be observed. d) Distinguishing features: Compared with the coating layer located only on the surface of the fabric, the membrane material of the physical interlocking bonding area 3 has a clear interlocking and anchoring relationship with the second yarn 1102, rather than a simple surface attachment.

[0116] (5) Air tightness test method: a) Testing equipment: an airtightness tester or a testing system consisting of a precision pressure sensor with an accuracy of ±0.1%FS, a pressure-stabilized air source, and a shut-off valve; b) Sample status: Complete airway unit or device as a whole, with all airway interface components 2 sealed and connected; c) Test environment: Temperature 23±2℃, relative humidity 50±10%; d) Test procedure: Fill the airway cavity 116 with compressed air to the set pressure, such as 0.2MPa, close the air source valve, let it stand for a set time, such as 5 minutes, and record the pressure values ​​before and after the pressure is maintained; e) Pressure drop calculation: Pressure drop (%) = (Pressure before holding pressure) (Pressure after holding pressure) / Pressure before holding pressure × 100%.

[0117] (6) Durability testing methods: a) Testing equipment: Pneumatic cycle testing machine, which can realize automatic cycle charging and discharging of air within a set pressure range; b) Cyclic conditions: Cycle the gas in and out within the set pressure range, such as 0-0.15MPa, with each cycle lasting 2-5 seconds; c) Number of cycles: Complete the cycle test according to the set number of cycles (e.g., 50,000 times); d) Air tightness retention rate: After the cycle is completed, a pressure holding test is performed according to the air tightness test method described above; e) Calculation of airtightness retention rate: Airtightness retention rate (%) = (1 The criterion for acceptance is calculated as follows: (Post-cycle pressure drop / Initial pressure drop) × 100%, or the post-cycle pressure drop ≤ Initial pressure drop × a set multiple (e.g., 1.2 times).

[0118] (7) Determination of "continuous airtight barrier membrane 115": The "continuous airtight barrier membrane 115" refers to a dense membrane layer formed on the inner surface of the airway that prevents gas leakage. The judgment criteria are: a) In cross-sectional microscopic observation, the film layer exhibits a dense morphology with no obvious fractures and interconnected pores; b) Functional assessment: The pressure drop in the airway does not exceed 5% under the condition of maintaining pressure at 0.2 MPa for 5 minutes. Meeting any of the above conditions is sufficient to identify it as a continuous airtight barrier membrane 115.

[0119] Second Embodiment The pneumatic pressing device for woven air channels provided in the second embodiment of the present invention differs from the first embodiment described above in that: The first yarn 1101 includes a covering structure, wherein the covering layer of the covering structure includes thermoplastic polyurethane, and the core layer of the covering structure includes heat-resistant fiber.

[0120] It is worth noting that the coated structure uses one fiber as the core and another fiber is wrapped around the surface of the core yarn in a spiral manner. It is made by coated spinning process. Compared with the core-sheath structure, the distribution of its outer material is more flexible.

[0121] In the application scenario of this application, the core yarn is also made of heat-resistant fiber, providing basic mechanical support; the thermoplastic polyurethane fiber is tightly wrapped around the outside of the core yarn in a spiral winding manner, forming a continuous coating layer. The characteristics of this type of yarn are its flexible manufacturing process, adaptability to core yarns of different thicknesses, and adjustable coating coverage, ensuring an effective supply of thermoplastic polyurethane components during hot pressing. Simultaneously, the yarn exhibits good overall softness, making it more suitable for knitting and weaving, and less prone to yarn breakage during the weaving process.

[0122] The advantages of this design are that the coating structure further enhances the flexibility and weaving adaptability of the yarn, reduces the risk of yarn breakage during complex pattern weaving, improves production efficiency, and the flexible manufacturing process allows the yarn to be customized according to product requirements, enhancing product design flexibility. The continuous coating layer ensures a uniform supply of TPU during hot pressing, improving the uniformity and density of the film. Third Embodiment The difference between the pneumatic pressing device for braided airways provided in the third embodiment of the present invention and its preparation method and the above-mentioned first embodiment lies in: taking the calf sleeve as an example in this embodiment, the yarn selection, zonal knitting structure, presetting method of the gas path interface component 2, and the integrated process of hot pressing in-situ film forming and sealing of the device of the present invention are described. This device is used for purposes such as sports relaxation, rhythmic pressing, and tactile feedback. The preparation steps are as follows: The following yarn configuration is adopted in this embodiment: The specification of the second yarn 1102 is selected as 150 denier, 48 filaments, high-strength polyester fully drawn yarn, with a melting point of about 260°C, a breaking strength of not less than 4.5 cN / dtex, and is used to form the first skeleton layer 114 and the second skeleton layer 120. Through process verification, the thermal shrinkage rate of this yarn under the hot pressing conditions of a hot pressing temperature of 165°C, a hot pressing pressure of 0.4 MPa, and a holding time of 45 s is less than 3%, the breaking strength retention rate is greater than 95%, and there is no visually visible adhesion. It is determined that its Tm2 is about 220°C; The specification of the first yarn 1101 is selected as 100 denier TPU core-shell composite monofilament, the core layer is high-strength polyester filament, accounting for about 40%; the skin layer is TPU, accounting for about 60%; the melting point of TPU is about 150°C (DSC measurement, peak temperature of the endothermic peak), denoted as Tm1, and is used to form the inner wall functional layer; The elastic auxiliary yarn is selected as 40 denier spandex covered yarn and is used for the circumferential elasticity and fitting of the sleeve.

[0123] The above materials satisfy the temperature relationship required for selective melting: Tm1 (150°C) < Tprocess (165°C) < Tm2 (220°C), and Tprocess is about 15°C higher than Tm1 and about 55°C lower than Tm2, meeting the process stability requirements.

[0124] During knitting, a 14 - gauge computerized knitting machine is used for full - forming knitting to obtain a seamless sleeve structure, and an air path structure 11 and a breathable structure 12 are formed on the plane; The air path structure 11 adopts a double - layer bag - like structure, so that the first fabric layer and the second fabric layer form a closed inner cavity; the relatively inner surfaces close to the inner cavity are mainly formed by the first yarn 1101 to form the first functional layer 113 and the second functional layer 119, and the outer sides are mainly formed by the second yarn 1102 to form the first skeleton layer 114 and the second skeleton layer 120.

[0125] The double - layer structure is edge - sealed 117 along the edge of the air path contour by using full - needle interlacing or high - density tissue to form a closed boundary.

[0126] The limit knotting structure 118 forms a dot - matrix knotting in the air path at an interval of 10 mm × 10 mm (center distance between adjacent knotting points), and the limit knotting yarn is connected to the upper and lower layers of the first yarn 1101 by means of gathering to limit the maximum expansion thickness of the air path to not more than 15 mm.

[0127] The breathable structure 12 includes a single-layer mesh fabric 121 between adjacent air channels, and is continuously connected to the air channel structure 11 through a transition connection section 122 to maintain breathable and moisture-permeable properties, with an air permeability of not less than 150 L / (m²·s).

[0128] The gas interface assembly 2 adopts a combination structure of a flange base 21 and a connector 22 made of TPU material. The flange 211 has a diameter of about 15mm and a thickness of about 0.8mm. The TPU used in the flange base 21 has a melting point of about 145℃, which is about 5℃ different from the melting point of the TPU component in yarn B, thus meeting the material compatibility requirements.

[0129] When weaving reaches the reserved pocket position at the interface, pause weaving, place the flange base 21 between the first composite layer 111 and the second composite layer 112, and let the connecting nozzle 22 protrude from the fabric surface; then continue weaving to complete the sealing edge 117, so that the flange base 21 is embedded in the air passage structure 11 and achieves preliminary positioning.

[0130] This embodiment uses a pneumatic isolation method. An external air source is connected to the connector 22 to introduce 0.15MPa compressed air into the inner cavity 116 of the airway, keeping the airway open during the thermo-pressurization process to prevent the upper and lower inner walls from sticking together.

[0131] The hot pressing film formation process parameters are as follows: hot pressing temperature Tprocess=165℃; hot pressing pressure 0.4MPa; holding time 45 seconds.

[0132] After the semi-finished sleeve is fitted onto the cylindrical metal mold, it is placed in a hot pressing device. Under the combined action of hot pressing and internal air pressure, the TPU component in yarn B melts and flows, filling the knitting pores, forming a continuous airtight barrier film 115 on the inner surface of the air passage, and forming a physical interlocking bonding area 3 with the first skeleton layer 114 and the second skeleton layer 120; at the same time, the flange base 21 and the airtight barrier film 115 are thermally fused to form a continuous sealed connection interface.

[0133] After hot pressing, maintain the internal air pressure and allow it to cool naturally to below 55°C to complete the shaping of the airtight barrier membrane 115. Then, perform softening and hydrophilic finishing, with the finishing temperature not exceeding 60°C, and install quick-connect fittings to complete assembly.

[0134] The performance test results of this embodiment are shown in Table 1:

[0135] Table 1 Fourth embodiment Please refer to Figure 13The fourth embodiment of this invention provides a pneumatic compression device with woven airways and its preparation method, which differs from the first embodiment in that it is a wearable pneumatic compression brace for relaxing the neck and upper back, providing rhythmic massage, supporting sedentary work, and providing tactile alerts. The brace has a shawl-like or vest-like structure and is used to cover the upper trapezius muscle, superior angle of the scapula, and upper back area to relieve neck and shoulder muscle tension and fatigue caused by prolonged desk work or sitting. The specific preparation steps are as follows: This embodiment uses the following yarn configuration: The second yarn 1102 is made of 200 denier, 96-filament high-strength fully drawn polyester yarn, used to form the first skeleton layer 114 and the second skeleton layer 120. Process verification determined that Tm2 is approximately 225℃.

[0136] The first yarn 1101 is made of 120 denier TPU-coated composite yarn, with TPU as the coating layer and a melting point of Tm1 = 148℃. The core layer is made of high-strength polyester filament with a TPU content of about 55%, which is used to form the first functional layer 113 and the second functional layer 119.

[0137] The elastic auxiliary yarn is made of 70 denier spandex-covered yarn and is used for overall fit and rebound of the protective gear.

[0138] The skin-contact yarn is made of fine denier nylon stretch textured yarn and is used on the skin-contact side to improve the feel and abrasion resistance.

[0139] During knitting, six parallel air passage structures 11 are set on the shoulders, neck and upper back. The air passage structures 11 are distributed in an arc shape along the shoulder line to the upper angle of the scapula. The width of a single air passage structure 11 is about 25mm. A breathable structure 12 is set between adjacent air passage structures 11.

[0140] The limiting connection structure 118 is arranged in a dot matrix pattern within the airway cavity 116, with a dot matrix spacing of approximately 10 mm.

[0141] The air interface component 2 is centrally located on one side of the back of the protective gear and uses a 6-way interface to connect to an external controller in order to realize the air supply connection and control of multiple air channels.

[0142] In this embodiment, a pneumatic isolation method is used, in which 0.18MPa compressed air is introduced into each air passage to keep the air passage in an open state during the thermo-pressurization process.

[0143] The parameters for the hot-press in-situ film formation process are as follows: hot pressing temperature Tprocess = 168℃, approximately 20℃ higher than Tm1 and approximately 57℃ lower than Tm2; hot pressing pressure 0.45MPa; holding time 40 seconds.

[0144] After hot pressing, maintain the internal air pressure and cool to below 55°C to complete film formation and shaping.

[0145] The performance test results of this embodiment are shown in Table 2:

[0146] Table 2 First comparison The same material and weaving structure as the third embodiment are used, the difference being that the hot pressing temperature is set to 135°C, which is lower than the TPU melting point Tm1, where Tm1 is about 150°C; other process parameters remain unchanged: hot pressing pressure 0.4MPa, holding time 45 seconds.

[0147] When the hot-pressing temperature is below Tm1, the TPU components do not fully melt, only undergoing localized softening, making it difficult to fully flow and fill the coil gaps. The resulting airtight barrier film 115 contains unfused areas and micropores, exhibiting uneven and discontinuous thickness.

[0148] The airtightness test showed that after holding at 0.2 MPa for 5 minutes, the pressure drop was 15%, which is higher than the ≤2% level of Example 1 and does not meet the airtightness requirements.

[0149] Scanning electron microscopy revealed that the airtight barrier membrane 115 has a porous structure and unfused areas, with uneven membrane thickness (0.05-0.35 mm), and its interlocking with the first skeleton layer 114 and the second skeleton layer 120 is weak, with a penetration depth of only about 20-40 μm.

[0150] This comparative example shows that the hot pressing temperature needs to be higher than Tm1 to ensure that the TPU components fully melt and flow to form a continuous and dense airtight barrier film 115; if the temperature is too low, the film quality will be insufficient, making it difficult to achieve the airtight effect of the present invention.

[0151] Second pair of proportions Using the same materials and weaving structure as in the third embodiment, the hot pressing temperature is set to 230°C, which is higher than the upper limit temperature Tm2 of the structural stability of the first skeleton layer 114 and the second skeleton layer 120 under hot pressing conditions, where Tm2 is approximately 220°C; other process parameters remain unchanged.

[0152] The high-strength polyester yarn underwent significant heat shrinkage, with a shrinkage rate of approximately 12%. Some yarns became stuck together, and the mechanical constraint capacity of the first skeleton layer 114 and the second skeleton layer 120 decreased. The air channel structure 11 shrank and deformed after hot pressing, and the fabric surface showed melting adhesion, abnormal luster, and a hardened hand feel.

[0153] Airway inflation tests showed that due to insufficient mechanical constraints of the first skeleton layer 114 and the second skeleton layer 120, irregular swelling occurred after the airway was inflated, making it difficult to maintain a flat or near-flat feature and reducing the uniformity of pressure; at the same time, changes in the appearance and feel of the fabric affected the wearing experience.

[0154] This comparative example shows that the hot pressing temperature needs to be lower than Tm2 to ensure that the first skeleton layer 114 and the second skeleton layer 120 maintain structural integrity and continue to provide mechanical constraints; excessively high temperatures will cause the skeleton layers to melt or thermally deform, thereby affecting the airway morphology control and pressing effect.

[0155] Third pair of proportions The same knitted structure as the third embodiment is used, but instead of in-situ film formation, an airtight layer is formed on the inner surface of the airway structure 11 using a conventional TPU coating method.

[0156] Coating process conditions: Solvent-based TPU coating adhesive with a solid content of 30% is used. It is applied to the inner surface of the airway by scraping, with a coating amount of about 100g / m². It is dried at 80℃ for 30 minutes. The coating is repeated twice, and the final dry film thickness is about 0.3mm.

[0157] The coating solution achieves airtightness with an initial pressure drop of about 3% in the initial stage, but after 50,000 cycles of charging and discharging at 0 MPa to 0.15 MPa, the airtightness retention rate is 78%, which is lower than the ≥95% of the embodiment of the present invention.

[0158] Scanning electron microscopy revealed interfacial cracks and peeling between the coating and the fabric substrate. This indicates that the coating and fiber are mainly surface-attached and lack physical interlocking, leading to interfacial failure under cyclic stress.

[0159] Interface bonding morphology comparison: Cross-sectional SEM observation shows that the membrane layer of the traditional coating solution is mainly located on the fiber surface, with clear boundaries and a penetration depth of less than 20μm, lacking the penetration and anchoring characteristics into the fiber bundle gaps; in contrast, the embodiment of the present invention shows that the membrane material enters the fiber bundle gaps to form an embedded interlocking interface, with a penetration depth of 60-120μm.

[0160] The comparative example shows that the in-situ film formation and physical interlocking mechanism of the present invention has higher durability performance than traditional coating methods. Although the process path of traditional coating is different, its interface bonding morphology makes it more prone to deterioration of airtightness under cyclic stress.

[0161] In summary, this invention achieves improvements in airtight pressure resistance, wearability, durability, interface sealing reliability, and manufacturing consistency through optimization of the airtight structure formation path, interface bonding morphology, and process chain. It possesses at least the following advantages: First, the air passage structure 11 forms an airtight barrier membrane 115 through in-situ TPU film formation to achieve press-to-release inflation and deflation; the breathable structure 12 retains the gaps between the knitted loops and maintains breathable and moisture-permeable properties, with a breathability of not less than 150L / (m²·s). Since the airtightness and density are mainly limited to the air passage structure 11, the breathable structure 12 does not form a continuous dense layer. Thus, while meeting the airtightness and pressure resistance stability required for air passage inflation and deflation, the moisture and heat resistance of the breathable structure 12 is reduced, which is beneficial to improving thermal and moisture comfort during long-term wear. Secondly, the limiting connection structure 118 connects the first composite layer 111 and the second composite layer 112, which is used to limit the expansion shape of the airway after inflation, so that the airway cross-section remains flat or nearly flat. By constraining the expansion thickness and cross-sectional shape, the effective contact area between the airway and the limb can be increased, reducing the probability of pressure concentration caused by local bulges and the formation of local non-contact areas, thereby improving the uniformity of compression output and the stability of the fit. Third, the airtight barrier membrane 115 is formed by in-situ melting and leveling of low-melting-point TPU components under hot-pressing conditions, and forms a physically interlocked bonding zone 3 (penetration depth not less than 50μm) with the first and second skeleton layers through melt penetration and interlocking between fiber bundles. Compared with coating or lamination composite methods that mainly rely on surface adhesion, this interlocked bonding zone can reduce the risk of interface cracking, peeling or deterioration of the sealing boundary caused by relative interface slippage and stress concentration under repeated deformation conditions of cyclic inflation and deflation, thereby helping to improve the airtightness performance and structural durability; Fourth, in this invention, a thermoplastic flange base 21 is pre-placed between the two layers of fabric in the air passage structure 11, and simultaneously melts and welds with the TPU component of the inner wall of the air passage during the hot-pressing in-situ film formation process, forming a continuous sealed connection interface between the flange base 21 and the airtight barrier membrane 115. This material-compatible melt-bonding path reduces the dependence on adhesive or mechanical clamping connection methods at the interface, which helps to reduce the risk of micro-leakage, loosening, and interface fatigue failure under cyclic loads in the interface area, and improves the stability of the interface seal and connection.

[0162] Fifth, the airtight pressure-bearing structure of the present invention is formed by in-situ film formation inside the fabric, which reduces the reliance on independent thin-film inner airbags or large-area film / thick coating structures, thus providing a basis for reducing the overall thickness and weight in the structural path. At the same time, the airtight barrier membrane 115 is disposed on the inner surface of the airway and does not penetrate to the outermost surface of the main body 1, which helps to maintain the smooth feel of the outer side of the main body 1 and reduce the impact on the degree of freedom of movement during dynamic activities.

[0163] Sixth, the present invention adopts a process route of fully formed partitioned weaving, component pre-positioning and hot-pressing in-situ sealing, which reduces the number of assembly steps and heterogeneous material interfaces, reduces station complexity and assembly sensitivity, and helps to improve batch manufacturing consistency and quality stability.

[0164] It should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0165] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

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