Composite structure, guide sheath and preparation method of composite structure

Abstract

The invention discloses a composite structure, a guide sheath and a preparation method of the composite structure, and belongs to the technical field of medical instruments.The composite structure comprises an outer tube body, an inner tube body and a braid ply, the inner tube body is arranged on the inner wall of the outer tube body, and a guide channel is axially formed in the inner tube body; the braid layer is arranged between the outer pipe body and the inner pipe body, and under the condition of a vacuum sealing environment, the braid layer is soaked in an elastic hot melt liquid material to be solidified and then is compounded between the outer pipe body and the inner pipe body in the circumferential direction; and / or, under the condition that the braid layer is soaked in the elastic hot melt liquid material, the current sealing environment where the braid layer is located is gradually pressurized, and after the braid layer is solidified, the braid layer is composited between the outer pipe body and the inner pipe body in the circumferential direction. Compared with the prior art, the inner layer structure of the guide sheath can be effectively prevented from layering when the guide sheath is used.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a composite structure, a guide sheath and a method for preparing the composite structure. Background Art

[0002] The guide sheath is a device commonly used in the medical field, mainly used to guide other medical devices into the patient's body cavity. The structure of the guide sheath includes an outer protective layer, a middle support layer and an inner layer. The guide sheath is usually used in interventional treatment, especially in medical operations such as endoscopy and vascular interventional treatment, and plays a vital role.

[0003] After long-term practice, the inventors found that during surgery, the inner layer structure of the guide sheath often delaminates, causing the adhesion between the inner layer and other layers to fail or separate, thereby affecting the function of the guide sheath. Summary of the invention

[0004] The invention discloses a composite structure, a guide sheath and a method for preparing the composite structure, so as to solve the technical problem of the delamination phenomenon existing in the inner layer structure of the guide sheath in the related art.

[0005] In order to solve the above problems, the present invention adopts the following technical solutions: In a first aspect, the present invention provides a composite structure for a guide sheath, comprising an outer tube body, an inner tube body and a braided layer, wherein the inner tube body is arranged on the inner wall of the outer tube body, a guide channel is axially arranged in the inner tube body, and the braided layer is arranged between the outer tube body and the inner tube body, wherein, in a vacuum sealed environment, the braided layer is immersed in an elastic hot-melt liquid material for solidification, and after a coating layer is formed on the surface of the braided layer, it is circumferentially compounded between the outer tube body and the inner tube body; and / or, when the braided layer is immersed in the elastic hot-melt liquid material, the sealing environment in which the braided layer is currently located is gradually pressurized to solidify the braided layer, and after a coating layer is formed on the surface of the braided layer, it is circumferentially compounded between the outer tube body and the inner tube body.

[0006] In a second aspect, the present invention provides a guide sheath comprising the composite structure described in the first aspect.

[0007] In a third aspect, the present invention provides a method for preparing a composite structure, which is used to prepare the composite structure described in the first aspect, comprising the following steps: Filling the elastic hot-melt liquid material into a sealed container, placing the woven layer in a blank area above the elastic hot-melt liquid material in the container, and adjusting the air pressure in the container so that the container is in a negative pressure environment; The braided layer is immersed in the elastic hot-melt liquid material, and then the air pressure in the container is continuously adjusted to place the container in a positive pressure environment, so that the elastic hot-melt liquid material fills the periphery of the braided layer and squeezes out the air in the braided layer at the same time; Lifting the braided layer immersed in the elastic hot-melt liquid material to a blank area in the container, so that excess elastic hot-melt liquid material on the surface of the braided layer drips off; Applying wind force to the braided layer in the blank area of ​​the container to accelerate the solidification of the braided layer impregnated with the elastic hot-melt liquid material under the effect of air drying; The braided layer, the inner tube body and the outer tube body impregnated with the elastic hot-melt liquid material are placed in a mold, and the composite structure described in the first aspect is formed through an extrusion process.

[0008] The technical solution adopted by the present invention can achieve the following beneficial effects: 1. The present invention applies prestress to both ends of the braided layer, allowing it to be impregnated with an elastic hot-melt liquid material in a stretched state, and releases the stretching after solidification, so that the elastic hot-melt liquid material can fill the pores of the braided layer more deeply, and squeeze the material therein during contraction, which is beneficial to enhancing the bonding force between the braided layer and the elastic hot-melt liquid material. In addition, a concave-convex surface structure is formed on the surface of the braided layer, and the close fit between the braided layer and the inner tube body or the outer tube body is utilized to further improve the bonding strength between the layers, which helps to reduce the possibility of stratification caused by long-term use or external forces. At the same time, the composite structure uses the same material as the inner tube body and the outer tube body (such as TPU or PTFE), so that a stable sealing structure is formed after the ends are hot-melted, which is beneficial to reduce the risk of interlayer delamination or interface detachment caused by material incompatibility, and improves the stability of the composite structure as a whole; 2. By arranging a prestressed braided layer at the end of the composite structure, it can shrink inward under the action of its own contraction force after cutting, and drive the cut surfaces of the inner tube body and the outer tube body to converge inward, forming a first closed part and a second closed part, thereby sealing the cut surface of the braided layer under the action of stress. At the same time, by coating the end area with medical glue, the first closed part and the second closed part form a more stable adhesion with the cut surface of the braided layer, which is beneficial to improving the sealing performance of the end and reducing the possibility of delamination or peeling. In addition, the annular convex ring is embedded between the braided layer and the inner tube body and the outer tube body, which can not only support the composite structure in sections to avoid the spread of delamination, but also play a sealing role to a certain extent, so that even if delamination occurs in a certain section, it will not easily spread to the entire composite structure, further enhancing the sealing and durability; 3. The present invention forms a concave-convex surface by air-drying after the braided layer is impregnated with an elastic hot-melt liquid material, so that the bonding mode between the braided layer and the inner and outer tube bodies is changed from the original smooth surface contact to a combination mode of multi-point contact and interlocking contact, thereby effectively increasing the mechanical bite force and interlayer friction force per unit area and improving the adhesion stability. In addition, the provision of the annular convex ring can not only provide additional structural support in the axial direction and enhance the overall strength of the braided layer, but also control the inner diameter of the braided layer within a specified range, thereby reducing deformation or fatigue damage caused by long-term use. Coupled with the high elasticity and wear resistance of the TPU material, the composite structure can maintain good flexibility and impact resistance in a complex mechanical environment, thereby extending its service life and improving the overall reliability of the guide sheath. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0010] Figure 1 is a schematic diagram of the structure of the guide sheath in some embodiments of the present application; Figure 2 is a partial schematic diagram of a composite structure in some embodiments of the present application; Figure 3 is a partial cross-sectional view of a composite structure in some embodiments of the present application; Figure 4 This is a schematic diagram of the layer structure distribution of the composite structure in some embodiments of the present application. Figure 1 ; Figure 5 This is a schematic diagram of the layer structure distribution of the composite structure in some embodiments of the present application. Figure 2 ; Figure 6 This is a schematic diagram of the layer structure distribution of the composite structure in some embodiments of the present application. Figure 3 ; Figure 7 This is a schematic diagram of the layer structure distribution of the composite structure in some embodiments of the present application. Figure 4 .

[0011] In the figure: 100, outer tube body; 110, first closing part; 200, inner tube body; 210, guide channel; 220, second closing portion; 300, braided layer; 400, annular convex ring; 500. Coating layer. DETAILED DESCRIPTION

[0012] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0013] The terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are generally of one type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0014] In each embodiment of the present application, "proximal end" and "distal end" refer to the position of each component relative to the user in the use environment, wherein the end closer to the user is designated as the "proximal end" and the end farther from the user is designated as the "distal end".

[0015] In the related technology, a guide sheath is a device commonly used in the medical field, mainly used to guide other medical devices into the patient's body cavity. Guide sheaths are usually used in interventional treatments, especially in medical operations such as endoscopic examinations and vascular interventional treatments, where they play a vital role. The guide sheath provides a channel through its tubular structure, allowing other medical devices to smoothly enter the target area, thereby improving the accuracy and safety of the operation. The use of a guide sheath is usually to insert it into a body cavity, and then guide endoscopes, catheters, needles and other instruments into the body through the space it provides to complete the diagnosis and treatment operation.

[0016] The structure of the guide sheath is usually composed of multiple layers of materials to ensure its strength, flexibility and safety during use. Generally speaking, the structure of the guide sheath includes an outer protective layer, a middle support layer and an inner layer. The protective layer is generally made of a thinner material with a smooth surface. Its main function is to protect the guide sheath from external physical damage during use and to facilitate insertion into the body cavity during operation. The middle layer is usually made of a stronger material to enhance the structural rigidity of the guide sheath and ensure that it can maintain a stable shape under a certain pressure. The inner layer is also a thinner structure, usually with a smooth surface to reduce friction and ensure that other medical devices can pass through the guide sheath smoothly.

[0017] However, although the guide sheath has taken multiple protections and functionalities into consideration in its structural design, in actual use, since the guide sheath needs to enter the cavity in the patient's body, it is often affected by factors such as the shape of the cavity in the body, the operation angle, and the insertion pressure, causing the guide sheath to bend. Especially during the operation, the bending of the guide sheath is often unavoidable. However, after the guide sheath is bent, the structure of the inner layer may be delaminated, resulting in failure or detachment of the bonding between the inner layer and other layers, thereby affecting the function of the guide sheath.

[0018] The delamination problem of the guide sheath mainly originates from the braided layer in its structure. The guide sheath is usually made of multiple layers of composite materials, in which the middle layer is usually a braided layer, which plays a role in enhancing strength and improving flexibility. During the manufacturing process, the braided layer is combined with the inner and outer layers through a composite process. However, during this process, some gas often remains between the composite layers, especially during the production process, the material is not completely gas-free under high temperature or pressure, resulting in tiny bubbles or air gaps between the inner and outer layers and the braided layer.

[0019] In addition, the production process of the guide sheath is usually to first produce a longer guide sheath tube, and then cut it into the required length according to the use requirements. During this process, the gas in the long tube may not be discharged in time, especially when the tube is bent or cut, the residual gas may be trapped between the middle layer and the inner layer. When the guide sheath is bent for use, especially during operation, due to the tortuosity of the body cavity and the flexibility of the guide sheath itself, the tube will bend and deform to a certain extent. At this time, the gas that originally remained in the production process may be squeezed between the middle layer and the inner layer, forming bubbles or gaps, which will cause the adhesion between the inner layer and the middle layer to decrease, and even delamination.

[0020] This delamination problem not only affects the strength and stability of the guide sheath, but may also cause a series of problems in actual operation. First, the guide sheath may lose its original flexibility and structural stability after delamination, making it more prone to damage or deformation during use. Secondly, the entry of gas between the inner layer and the middle layer may also cause poor operation of the guide sheath, increase the resistance of the insertion cavity, and even affect the guidance accuracy of the medical device. Therefore, how to effectively remove the gas generated during the production process and prevent the gas from entering the layers when the guide sheath is bent is a major problem in the current design and production of guide sheaths.

[0021] Based on the above technical problems, the present invention provides a composite structure, a guide sheath and a method for preparing the composite structure.

[0022] The following is combined with Figures 1 to 7, a composite structure, a guide sheath and a method for preparing the composite structure provided in the present application are described in detail through specific embodiments and their application scenarios.

[0023] First, combining Figure 1 , Figure 2 as well as Figure 3 The present application provides a composite structure for use in a guide sheath, which includes an outer tube body 100, an inner tube body 200, and a braided layer 300. The inner tube body 200 is arranged on the inner wall of the outer tube body 100, and a guide channel 210 is axially arranged in the inner tube body 200. The braided layer 300 is arranged between the outer tube body 100 and the inner tube body 200 to achieve the effect of enhancing strength and improving flexibility. In actual use, the outer tube body 100 is first inserted into the lesion inside the human body through the human body cavity, and then the surgical instrument is extended to the lesion inside the human body through the guide channel 210 formed in the inner tube body 200 to achieve the purpose of guidance.

[0024] Exemplarily, the braided layer 300 is made of a metal material, such as nickel-titanium alloy, tungsten alloy or stainless steel (304 type, 316L type), etc., so that the support strength of the braided layer 300 between the outer tube body 100 and the inner tube body 200 can be increased. It is worth noting that in practical applications, the braided layer 300 made of stainless steel is still commonly used in the art, the nickel-titanium alloy is mainly used for the guide sheath requiring high flexibility, and the tungsten wire is usually used to enhance the X-ray visibility, so the specific selection of the material of the braided layer 300 depends on the use scenario and performance requirements of the guide sheath.

[0025] Exemplary, combined Figure 3 , Figure 4 In a vacuum sealed environment, the braided layer 300 is immersed in an elastic hot-melt liquid material for solidification, and after a coating layer 500 is formed on the surface of the braided layer 300, it is circumferentially compounded between the outer tube body 100 and the inner tube body 200; and / or, when the braided layer 300 is immersed in an elastic hot-melt liquid material, the sealing environment in which the braided layer 300 is currently located is gradually pressurized to solidify the braided layer 300, and after a coating layer 500 is formed on the surface of the braided layer 300, it is circumferentially compounded between the outer tube body 100 and the inner tube body 200.

[0026] On this basis, first, the braided layer 300 is placed in a vacuum sealed environment. In this environment, due to the low external air pressure, the tiny bubbles that may exist inside the braided layer 300 are discharged, thereby reducing the presence of residual gas. Subsequently, the braided layer 300 is transferred to the elastic hot-melt liquid material for impregnation. The elastic hot-melt liquid material in a molten state can penetrate into the tiny pores of the braided layer 300 and fill the gaps that may originally exist in the braided layer 300. In this process, the fluidity of the elastic hot-melt liquid material enables it to enter various areas of the braided layer 300, and to a certain extent improves the overall density of the braided layer 300, and eventually forms a coating layer 500 on the surface of the braided layer 300. In addition, in order to further reduce the residual gas in the braided layer 300, a gradual pressurization method is adopted to gradually transition the environment in which the braided layer 300 is impregnated from normal pressure to a higher air pressure state. In the process of gradually increasing pressure, the tiny bubbles that may be trapped are further compressed or discharged under the action of pressure, and the liquid material in a molten state can further fill the gaps that may originally exist, so that the braided layer 300 has a higher integrity and density after solidification.

[0027] After completing the above steps, the braided layer 300 is cured after an appropriate period of time. After curing, the interior of the braided layer 300 has been basically filled with elastic hot-melt liquid material, so that it is not easy to cause gas retention problems during the subsequent compounding process with the outer tube body 100 and the inner tube body 200. Subsequently, the cured braided layer 300 is lifted to allow its excess liquid material to flow out under the action of gravity, further reducing the accumulation of liquid material so as to better meet the flexibility requirements of the guide sheath. Finally, after a mold extrusion process, the processed braided layer 300 is compounded with the inner tube body 200 and the outer tube body 100 to obtain a complete composite structure.

[0028] In summary, after the above processing, the composite structure of this embodiment improves the overall stability of the composite structure to a certain extent, making it difficult for the guide sheath to separate from the layers when it is bent, thereby improving the use effect of the guide sheath. In addition, since the braided layer 300 has undergone the processes of vacuum exhaust, elastic hot-melt liquid material filling and pressurized curing before composite, the composite structure can reduce the problem of interlayer adhesion failure caused by bubbles to a certain extent during actual use, thereby improving the durability and reliability of the guide sheath.

[0029] In some embodiments, the two ends of the braided layer 300 are in a stretched state after being prestressed, and then immersed in the elastic hot-melt liquid material, and the stretching is released after the surface is covered with the elastic hot-melt liquid material. Exemplarily, the tension applied to the two ends of the braided layer 300 is stretched in opposite directions along the axis of the braided layer 300.

[0030] In order to further optimize the filling effect of the braided layer 300 and enable its internal pores to be more fully filled with the elastic hot-melt liquid material, the braided layer 300 is pre-stretched before dipping. Specifically, the two ends of the braided layer 300 give the braided layer 300 itself a certain prestress under the action of tension, so that it is in an axially stretched state. At this time, the braided structure of the braided layer 300 will expand to a certain extent under the action of tension, resulting in an increase in the gap between the originally tightly arranged braided wires. Subsequently, the braided layer 300 in the stretched state is immersed in the elastic hot-melt liquid material in the molten state. Since the internal pores of the braided layer 300 are relatively large in the stretched state, the elastic hot-melt liquid material in the molten state can more smoothly penetrate the pores of the braided layer 300 and fill the tiny gaps that may have existed, thereby reducing the residual bubbles to a certain extent.

[0031] After the impregnation is completed, the surface of the braided layer 300 is coated with a layer of elastic hot-melt liquid material, so that the material can form a uniform coverage on the entire surface of the braided layer 300. Subsequently, the tensile force applied to both ends of the braided layer 300 is released, and the braided layer 300 is restored to its initial non-stretched state. In this process, due to the retraction of the braided structure of the braided layer 300, the elastic hot-melt liquid material originally filled in the pores is squeezed to a certain extent, thereby further filling the gaps in the braided layer 300 and making its structure more compact. This method enhances the bonding strength between the braided layer 300 and the molten material to a certain extent, and reduces the interface separation problem caused by tiny bubbles that may exist during the production process. In addition, after the braided layer 300 is restored to its initial state, the filling method of the elastic hot-melt liquid material can enable it to have better buffering capacity in the subsequent bending process, which helps to reduce the risk of delamination of the composite structure in long-term use.

[0032] In some optional implementations, the inner tube body 200 and the outer tube body 100 are both made of PTFE material.

[0033] In some optional embodiments, the inner tube body 200 and the outer tube body 100 are both made of TPU material.

[0034] After such arrangement, in order to optimize the overall stability of the composite structure and reduce the probability of stratification to a certain extent, the material of the inner tube body 200 and the outer tube body 100 is made of the same polymer material, such as PTFE (polytetrafluoroethylene) or TPU (thermoplastic polyurethane). Since the inner tube body 200 and the outer tube body 100 are made of the same material, they have better compatibility during the hot melt treatment process. Specifically, after the composite structure is prepared, it is usually necessary to cut it according to a specific length to meet the use requirements of different medical devices. At the end of the composite structure after cutting, the inner tube body 200 and the outer tube body 100 can be melted and bonded at the end by hot melt treatment. Since the two materials are the same, a relatively uniform melting interface can be formed during the hot melt process, and a strong bond can be achieved after cooling, thereby forming a closed structure at the end of the composite structure.

[0035] This closed structure has certain advantages in practical applications. First, due to the effective fusion of the inner and outer layers of the end materials due to the hot melt effect, the end of the composite structure can reduce the risk of delamination to a certain extent. Secondly, the sealing structure at the end of the composite structure can provide additional structural stability during subsequent medical operations to avoid peeling problems caused by looseness between layers. In addition, in terms of the insertion force and smoothness of operation of medical devices, the sealed end of the composite structure can reduce the material peeling or burrs that may occur during insertion, thereby helping to improve the accuracy of medical operations.

[0036] In addition, the selection of PTFE or TPU as the material of the inner and outer tube bodies 100 also has a certain degree of adjustability, and different materials can be selected according to application requirements. For example, PTFE has good chemical inertness and high temperature resistance, and is suitable for medical environments with high requirements for chemical corrosion resistance and temperature resistance. TPU has good elasticity and wear resistance, and is more suitable for guide sheath structures that require a certain degree of flexibility and fatigue resistance. Therefore, according to different clinical needs, choosing the right material can improve the adaptability and reliability of the guide sheath to a certain extent.

[0037] In some embodiments, after the braided layer 300 is immersed in the elastic hot-melt liquid material and solidified, the braided layer 300 is in a tensile state with prestress applied at both ends, and then circumferentially composited between the outer tube body 100 and the inner tube body 200 to form a composite structure.

[0038] Exemplarily, after the formed composite structure is cut, the cut surface of the braided layer 300 shrinks inwardly with the cut surface of the outer tube 100 under the action of its own contraction force to form the first closed portion 110, and the cut surface of the inner tube 200 shrinks inwardly with the cut surface of the braided layer 300 to form the second closed portion 220. Further, the first closed portion 110 and the second closed portion 220 block the cut surface of the braided layer 300 under the action of stress, and the first closed portion 110 and the second closed portion 220 are both impregnated and bonded to the cut surface of the braided layer 300 by the adhesive material.

[0039] On this basis, in order to improve the overall stability of the composite structure and reduce the probability of delamination to a certain extent, during the manufacturing process of the composite structure, after the braided layer 300 is immersed in the elastic hot-melt liquid material and solidified, the two ends are kept in a prestressed tensile state, and then circumferentially compounded between the outer tube body 100 and the inner tube body 200 to form the final composite structure. This prestressed tensile state makes the braided layer 300 always in a certain internal stress state after compounding, and then can show specific deformation characteristics in the subsequent cutting process.

[0040] When the composite structure is completed, it is usually necessary to cut it according to a specific length. Since the braided layer 300 has been prestressed before the composite, after the cutting operation, the cut surface of the braided layer 300 will shrink axially toward the center due to its own contraction force. Compared with the braided layer 300, the cut surfaces of the inner tube body 200 and the outer tube body 100 remain basically intact in the initial state without applying additional prestress. However, due to the contraction of the braided layer 300, the cut surfaces of the inner tube body 200 and the outer tube body 100 will also be affected by a certain deformation, slightly protruding inward along the contraction direction of the braided layer 300, and then forming the first closed portion 110 and the second closed portion 220 at the cut end. The formation of the first closed portion 110 and the second closed portion 220 is conducive to reducing the interlayer gap, reducing the impact of the external environment on the interlayer structure, and making the overall end shape more stable.

[0041] In addition, the first closing part 110 and the second closing part 220 move closer to the cut surface of the braided layer 300 under stress, further strengthening the blocking effect on the cut end of the braided layer 300. Since the braided layer 300 is usually a braided structure, there may be certain capillary channels after it is cut, which may cause the interlayer structure to be exposed to the external environment, thereby affecting the structural stability. Therefore, medical glue is applied to the cut area for dip bonding, so that the first closing part 110 and the second closing part 220 can be better integrated with the cut surface of the braided layer 300. The penetration of the glue enables it to enter the braiding gap of the braided layer 300, and provide additional bonding force after curing, so that the sealing effect of the end is more stable. This treatment method not only improves the sealing performance of the end, but also can further reduce the probability of delamination, which helps to improve the reliability of the guide sheath in medical operations.

[0042] Through the above structure, after being cut, the composite structure can rely on the contraction effect of the braided layer 300 and the follow-up deformation of the inner tube body 200 and the outer tube body 100 to form a stable end-closed structure to a certain extent, and combined with the medical glue dipping bonding method, the overall end bonding strength is improved. This design helps to optimize the mechanical properties of the guide sheath, reduce the risk of interlayer peeling, and improve the safety and stability of medical devices during clinical use.

[0043] Exemplarily, the elastic hot-melt liquid material is configured as a TPU material. The selection of this material has many beneficial effects on the overall performance of the composite structure. First, the TPU material has good elasticity and flexibility, so that after being impregnated and cured in the gaps of the braided layer 300, it can adapt to the deformation of the guide sheath under bending or stress to a certain extent, thereby reducing interlayer stress concentration and reducing the possibility of delamination. In addition, the TPU material has good fluidity in a molten state, which enables the TPU to more fully fill the pores of the braided layer 300 during the impregnation process of the braided layer 300, and provide a higher adhesion after subsequent curing, so that the braided layer 300 is more tightly bonded to the inner and outer tube bodies 100.

[0044] Combined with the manufacturing process of the composite structure, in a vacuum sealed environment, when the braided layer 300 is immersed in the TPU molten liquid, due to the exhaust of gas under a vacuum state, it helps TPU to fully penetrate into the pore structure inside the braided layer 300, reduce air residue, and improve the uniformity of interlayer bonding. At the same time, curing is carried out under a gradually pressurized environment, so that TPU can further fill the gaps in the braided layer 300 under high pressure, and form a more stable interface bond after curing, thereby enhancing the overall strength of the composite structure. In addition, the braided layer 300 is impregnated in a stretched state, and the stretching is released after the surface is covered with TPU material. This process allows the TPU material to be more fully embedded in the fiber gaps of the braided layer 300, and after the braided layer 300 returns to its initial state, it further fills the pores, which helps to improve the overall bonding between the braided layer 300 and the composite structure and reduce the possibility of interlayer slippage.

[0045] In the process of forming a closed structure after the composite structure is cut, the hot melt properties of the TPU material also show certain advantages. Since both the inner tube body 200 and the outer tube body 100 can be made of TPU material, the TPU material at the cut end can be hot-melt bonded by local heating after cutting, so that the sealing effect of the first closed part 110 and the second closed part 220 is more stable. In addition, the TPU material has good wear resistance and tear resistance, so that the guide sheath can maintain good structural integrity during bending and multiple uses. Therefore, in this embodiment, the elastic hot-melt liquid material is configured as TPU, which not only helps to improve the overall bonding performance of the composite structure, but also can provide more stable physical properties during manufacturing and use, thereby improving the use effect of the guide sheath.

[0046] In some optional embodiments, such as Figure 5 As shown, along the axial direction of the guide channel 210 , a plurality of annular protrusions 400 are circumferentially spaced and embedded between the outer tube 100 and the braided layer 300 .

[0047] In some optional embodiments, such as Figure 6 As shown, along the axial direction of the guide channel 210 , a plurality of annular protrusions 400 are circumferentially spaced and embedded between the inner tube body 200 and the braided layer 300 .

[0048] In some optional embodiments, such as Figure 7 As shown, along the axial direction of the guide channel 210 , the braided layer 300 is circumferentially wound with a plurality of annular protrusions 400 at intervals, a portion of the annular protrusions 400 is in contact with the inner wall of the outer tube body 100 , and another portion is in contact with the outer wall of the inner tube body 200 .

[0049] On this basis, along the axial direction of the guide channel 210, a plurality of annular protrusions 400 are arranged between the outer tube body 100 and the braided layer 300, between the inner tube body 200 and the braided layer 300, or directly at intervals on the circumference of the braided layer 300. This structural design has a certain positive effect on improving the overall stability and anti-delamination performance of the composite structure. First, the annular protrusions 400 are arranged at intervals in the axial direction, so that the composite structure forms a plurality of relatively independent segmented areas. When the composite structure is delaminated in a certain section due to external stress or other factors during use, the annular protrusions 400 can play a role of physical blocking, so that the delamination phenomenon is locally restricted, and the possibility of the delamination phenomenon spreading along the axial direction is reduced. Even if the delamination phenomenon extends to adjacent sections, since there are still a plurality of annular protrusions 400 arranged at intervals in the future, they can still have a certain limiting effect on the extension of the delamination, thereby helping to reduce the risk of damage to the integrity of the composite structure.

[0050] Secondly, the setting of the annular bead 400 not only has an effect on the layering control, but also can enhance the support capacity of the braided layer 300 to a certain extent. Since the braided layer 300 is usually woven with metal or high-strength fiber, its main function is to provide radial support force to prevent the composite structure from radially shrinking or deforming when it is under negative pressure or lateral force. However, in some special application scenarios, the braided layer 300 may cause local deformation due to long-term force or manufacturing errors, thereby affecting the stability of the composite structure. By arranging the annular bead 400 inside the braided layer 300, additional support can be provided in the circumferential direction, making the radial shape of the braided layer 300 more stable, and maintaining the relative position of the inner tube body 200 and the outer tube body 100 to a certain extent, thereby controlling the inner diameter of the braided layer 300 to remain within the design range.

[0051] In addition, the material of the annular bead 400 can be selected according to specific needs, for example, it can be made of TPU, metal or other polymer materials with appropriate rigidity and elasticity. When the annular bead 400 is made of TPU or other elastic materials, it can adapt to a certain range of deformation under the action of external force, thereby enhancing the flexibility of the composite structure and reducing the influence of rigidity mutation on the overall mechanical properties. When the annular bead 400 is made of metal material, the overall strength of the structure can be further improved, so that the composite structure has better shape retention ability under high pressure environment. In the manufacturing process, the annular bead 400 can be installed by molding, injection molding or direct embedding, and can be designed with different distribution spacing and size to meet the application requirements of guide sheaths of different diameters and lengths. In general, by arranging multiple annular bead 400 inside the composite structure, the anti-delamination ability of the composite structure can be effectively improved, the supporting performance of the braided layer 300 can be enhanced, and the mechanical properties of the guide sheath can be optimized to a certain extent, thereby improving its reliability in medical and other fields.

[0052] In some embodiments, the outer surface and / or inner surface of the impregnated braided layer 300 forms a concave-convex surface (not shown in the figure) under air drying, and the concave-convex surface is used to fit tightly with the inner wall of the outer tube body 100 or the outer wall of the inner tube body 200. Exemplarily, the concave-convex surface can be a convex surface or a concave surface.

[0053] After the braided layer 300 is impregnated with the elastic hot-melt liquid material, its outer surface and / or inner surface forms a concave-convex surface after air drying. This structural design has a certain positive effect on improving the interlayer bonding force of the composite structure. Specifically, in the process of impregnating the braided layer 300 with the elastic hot-melt liquid material, the liquid material will cover the metal wire surface of the braided layer 300 and fill part of the braiding gap. During the air-drying process, due to the action of the airflow, the elastic hot-melt liquid material that is not fully solidified may form an uneven flow along the surface of the metal wire, resulting in the final solidified surface presenting an uneven shape. The formation of this concave-convex surface can, on the one hand, reduce the excess liquid accumulation that may exist on the surface of the braided layer 300, thereby avoiding the formation of an overly thick or uneven coating, affecting the overall mechanical properties of the composite structure; on the other hand, the presence of the concave-convex surface can increase the actual contact area between the braided layer 300 and the inner tube body 200 or the outer tube body 100 during the composite process, thereby improving the bonding strength between the layers.

[0054] When the braided layer 300 is compounded with the inner tube body 200 or the outer tube body 100, due to the presence of the concave-convex surface on the surface of the braided layer 300, its contact mode with the adjacent layer will be changed from the original smooth surface contact to a combination of multi-point contact and interlocking contact. This contact mode not only increases the mechanical bite effect per unit area, but also can improve the friction between layers to a certain extent, which is beneficial to improve the adhesion stability between the composite structure and reduce the risk of delamination that may occur during long-term use. In addition, when subjected to complex mechanical effects such as external bending, stretching or compression, the concave-convex surface structure can produce a certain stress dispersion effect locally, avoiding stress concentration on a single plane, thereby improving the overall durability and anti-peeling performance of the composite structure.

[0055] During the manufacturing process, the specific shape and distribution of the concave-convex surface can be adjusted by controlling parameters such as air-drying strength, wind direction, and initial coating thickness of the impregnation liquid to adapt to the design of guide sheaths of different specifications and application requirements. Therefore, by forming a concave-convex surface on the surface of the braided layer 300 and utilizing the close fit between it and the inner tube body 200 or the outer tube body 100, the interlayer bonding characteristics of the composite structure can be optimized to a certain extent, and its mechanical properties and use stability can be improved.

[0056] Illustratively, the wall thickness of the inner tube body 200 is greater than the wall thickness of the outer tube body 100, so that the inner tube body 200 can be kept smooth and the guide sheath can be more easily bent during actual use.

[0057] Second, combining Figure 1 to Figure 7 The present application also provides a guide sheath, comprising the composite structure of the first aspect.

[0058] In a third aspect, the present invention provides a method for preparing a composite structure, which is used to prepare the composite structure of the first aspect, comprising the following steps: Fill the elastic hot-melt liquid material into a sealed container, and place the braided layer 300 in a blank area above the elastic hot-melt liquid material in the container, and adjust the air pressure in the container so that the container is in a negative pressure environment; The braided layer 300 is immersed in the elastic hot-melt liquid material, and then the air pressure in the container is continuously adjusted to place the container in a positive pressure environment, so that the elastic hot-melt liquid material fills the periphery of the braided layer 300 and squeezes out the air in the braided layer 300 at the same time; Lift the braided layer 300 immersed in the elastic hot-melt liquid material to a blank area in the container, so that excess elastic hot-melt liquid material on the surface of the braided layer 300 drips off; Applying wind force to the braided layer 300 in the blank area of ​​the container to accelerate the solidification of the braided layer 300 impregnated with the elastic hot-melt liquid material under the effect of air drying; The braided layer 300 impregnated with elastic hot-melt liquid material, the inner tube body 200 and the outer tube body 100 are placed in a mold, and the composite structure of the first aspect is formed through an extrusion process.

[0059] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element.

[0060] In addition, it should be noted that the scope of the methods and devices in the embodiments of the present application is not limited to performing functions in the order shown or discussed, and may also include performing functions in a substantially simultaneous manner or in a reverse order according to the functions involved. For example, the described methods may be performed in an order different from that described, and various steps may be added, omitted, or combined. In addition, features described with reference to certain examples may be combined in other examples.

[0061] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A composite structure, applied to a guide sheath, characterized in that: The invention comprises an outer tube body (100), an inner tube body (200) and a braided layer (300), wherein the inner tube body (200) is arranged on the inner wall of the outer tube body (100), a guide channel (210) is axially arranged in the inner tube body (200), and the braided layer (300) is arranged between the outer tube body (100) and the inner tube body (200), wherein: In a vacuum sealed environment, the braided layer (300) is immersed in an elastic hot-melt liquid material for solidification, and after a coating layer (500) is formed on the surface of the braided layer (300), it is circumferentially compounded between the outer tube body (100) and the inner tube body (200); and / or, when the braided layer (300) is immersed in an elastic hot-melt liquid material, the sealed environment in which the braided layer (300) is currently located is gradually pressurized to solidify the braided layer (300), and after a coating layer (500) is formed on the surface of the braided layer (300), it is circumferentially compounded between the outer tube body (100) and the inner tube body (200).

2. The composite structure according to claim 1, characterized in that The two ends of the braided layer (300) are placed in a stretched state after prestress is applied, and then immersed in the elastic hot-melt liquid material, and the stretching is released after the surface is covered with the elastic hot-melt liquid material.

3. The composite structure according to claim 2, characterized in that: The inner tube body (200) and the outer tube body (100) are both made of PTFE material; Alternatively, the inner tube body (200) and the outer tube body (100) are both made of TPU material.

4. The composite structure according to claim 3, characterized in that After the braided layer (300) is immersed in an elastic hot-melt liquid material and solidified, the braided layer (300) is in a stretched state with prestress applied to both ends, and is then circumferentially composited between the outer tube body (100) and the inner tube body (200) to form the composite structure; After the formed composite structure is cut, the cut surface of the braided layer (300) shrinks inwardly following the cut surface of the braided layer (300) under the action of its own contraction force to form a first closed portion (110), and the cut surface of the inner tube body (200) shrinks inwardly following the cut surface of the braided layer (300) to form a second closed portion (220); The first closing portion (110) and the second closing portion (220) seal the cut surface of the braided layer (300) under stress, and the first closing portion (110) and the second closing portion (220) are both impregnated and bonded to the cut surface of the braided layer (300) by an adhesive material.

5. The composite structure according to claim 1, characterized in that: The elastic hot-melt liquid material is configured as TPU material.

6. The composite structure according to any one of claims 1 to 5, characterized in that: Along the axial direction of the guide channel (210), a plurality of annular protrusions (400) are embedded at circumferential intervals between the outer tube body (100) and the braided layer (300); Alternatively, along the axial direction of the guide channel (210), a plurality of annular protrusions (400) are circumferentially spaced and embedded between the inner tube body (200) and the braided layer (300); Alternatively, along the axial direction of the guide channel (210), the braided layer (300) is circumferentially wound with a plurality of annular convex rings (400) at intervals, and a portion of the annular convex rings (400) is in contact with the inner wall of the outer tube body (100), and another portion is in contact with the outer wall of the inner tube body (200).

7. The composite structure according to claim 6, characterized in that The outer surface and / or inner surface of the impregnated braided layer (300) forms a concave-convex surface under air drying, and the concave-convex surface is used to fit tightly with the inner wall of the outer tube body (100) or the outer wall of the inner tube body (200).

8. The composite structure according to claim 1, characterized in that The wall thickness of the inner tube body (200) is greater than the wall thickness of the outer tube body (100).

9. A guide sheath, characterized in that: A composite structure comprising any one of claims 1 to 8.

10. A method for preparing a composite structure, used for preparing the composite structure according to any one of claims 1 to 8, characterized in that: The following steps are involved: Filling an elastic hot-melt liquid material into a sealed container, placing a woven layer (300) in a blank area above the elastic hot-melt liquid material in the container, and adjusting the air pressure in the container so that the container is in a negative pressure environment; The braided layer (300) is immersed in the elastic hot-melt liquid material, and then the air pressure in the container is continuously adjusted so that the container is in a positive pressure environment, so that the elastic hot-melt liquid material fills the periphery of the braided layer (300) and simultaneously squeezes out the air in the braided layer (300); Lifting the braided layer (300) immersed in the elastic hot-melt liquid material to a blank area in the container, so that excess elastic hot-melt liquid material on the surface of the braided layer (300) drips off; Applying wind force to the braided layer (300) in the blank area of ​​the container, so that the braided layer (300) impregnated with the elastic hot-melt liquid material is accelerated to solidify under the effect of air drying; The braided layer (300) impregnated with elastic hot-melt liquid material, the inner tube body (200) and the outer tube body (100) are placed in a mold, and the composite structure according to any one of claims 1 to 8 is formed through an extrusion process.

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