Composite structure, guiding sheath and preparation method of composite structure

Abstract

The present invention discloses a composite structure, a guiding sheath and a preparation method of the composite structure, belonging to the technical field of medical devices. The composite structure includes an outer tube body, an inner tube body and a braided layer. The inner tube body is arranged on the inner wall of the outer tube body. A guiding channel is axially arranged in the inner tube body. 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 impregnated in an elastic hot-melt liquid material and cured, and then circumferentially compounded between the outer tube body and the inner tube body; and / or, when the braided layer is impregnated in the elastic hot-melt liquid material, the sealed environment where the braided layer is located is gradually pressurized and the braided layer is cured, and then circumferentially compounded between the outer tube body and the inner tube body. Compared with the prior art, the present invention can effectively prevent the inner layer structure of the guiding sheath from delaminating during use.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a composite structure, a guiding sheath and a preparation method of the composite structure. Background Art

[0002] A guiding sheath is a device commonly used in the medical field, mainly used to guide other medical devices into the body cavities of patients. The structure of the guiding sheath includes an outer protective layer, an intermediate support layer and an inner layer. The guiding sheath is usually used in interventional therapy, especially in medical operations such as endoscopic examination and vascular interventional therapy, and plays a crucial role.

[0003] Through long-term practice, the inventor found that during the operation, the inner layer structure of the guiding sheath often shows a delamination phenomenon, resulting in the adhesion failure or detachment between the inner layer and other layers, thus affecting the function of the guiding sheath. Summary of the Invention

[0004] The present invention discloses a composite structure, a guiding sheath and a preparation method of the composite structure to solve the technical problem of the delamination phenomenon existing in the inner layer structure of the guiding sheath in the related art.

[0005] To solve the above problems, the present invention adopts the following technical solutions:

[0006] In the first aspect, the present invention provides a composite structure applied to a guiding sheath, including an outer tube body, an inner tube body and a braided layer. The inner tube body is arranged on the inner wall of the outer tube body, a guiding 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. Among them, in a vacuum-sealed environment, the braided layer is impregnated in an elastic hot-melt liquid material for curing, 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 impregnated in the elastic hot-melt liquid material, the sealed environment where the braided layer is located is gradually pressurized and the braided layer is cured, 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.

[0007] In the second aspect, the present invention provides a guiding sheath, including the composite structure described in the first aspect.

[0008] In the third aspect, the present invention provides a preparation method of a composite structure for preparing the composite structure described in the first aspect, including the following steps:

[0009] Fill the elastic hot-melt liquid material into a sealed container, place the braided layer in the blank area above the elastic hot-melt liquid material in the container, and at the same time adjust the air pressure in the container to make the container in a negative pressure environment;

[0010] Immerse the braided layer into an elastic hot-melt liquid material, and then continue to adjust the air pressure inside the container to make the container in a positive pressure environment, so that the elastic hot-melt liquid material fills the periphery of the braided layer and simultaneously extrudes the air inside the braided layer;

[0011] Lift the braided layer impregnated with the elastic hot-melt liquid material to the blank area inside the container, so that the excess elastic hot-melt liquid material on the surface of the braided layer drips off;

[0012] Apply wind force to the braided layer in the blank area inside the container, so that the braided layer impregnated with the elastic hot-melt liquid material accelerates curing under the action of air drying;

[0013] Put the braided layer impregnated with the elastic hot-melt liquid material, the inner tube body and the outer tube body into a mold, and form the composite structure described in the first aspect through an extrusion process.

[0014] The technical solution adopted by the present invention can achieve the following beneficial effects:

[0015] 1. By applying prestress at both ends of the braided layer, the braided layer is impregnated with the elastic hot-melt liquid material in a stretched state and the stretching is released after curing, so that the elastic hot-melt liquid material can fill the pores of the braided layer more deeply, and at the same time squeeze the materials therein during contraction, which is beneficial to enhancing the bonding force between the braided layer and the elastic hot-melt liquid material. In addition, an uneven surface structure is formed on the surface of the braided layer, and by using its tight fitting effect with the inner tube body or the outer tube body, the interlayer bonding strength is further improved, which helps to reduce the possibility of delamination caused by long-term use or external force. At the same time, the composite structure uses the same materials as the inner tube body and the outer tube body (such as TPU or PTFE), so that a stable sealing structure is formed after hot melting at the end, which is beneficial to reducing the risk of interlayer peeling or interface detachment caused by material incompatibility, and overall improves the stability of the composite structure;

[0016] 2. By arranging a prestressed braided layer at the end of the composite structure, after being cut off, it can shrink inward under the action of its own contraction force, 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, so as to block the cut surface of the braided layer under the action of stress. At the same time, by coating medical glue in the end area, a more stable adhesion is formed between the first closed part and the second closed part and 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, by embedding annular convex rings between the braided layer and the inner tube body and the outer tube body, not only can the composite structure be segmented and supported to avoid the spread of delamination, but also it can 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 performance and durability;

[0017] 3. The present invention forms uneven surfaces by impregnating the braided layer with an elastic hot-melt liquid material and then air-drying it, which changes the combination mode of the braided layer and the inner and outer pipe bodies from the original smooth surface contact to a combination mode of multi-point contact and interlocking contact. Thereby, the mechanical biting force and the interfacial friction force per unit area are effectively increased, and the adhesion stability is improved. In addition, the setting of the annular convex rings can not only provide additional structural support in the axial direction, enhance the overall strength of the braided layer, but also control the inner diameter of the braided layer within a specified range, 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 guiding sheath. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 is a schematic structural diagram of a guiding sheath in some embodiments of the present application;

[0020] Figure 2 is a partial schematic diagram of a composite structure in some embodiments of the present application;

[0021] Figure 3 is a partial cross-sectional view of a composite structure in some embodiments of the present application;

[0022] Figure 4 is a schematic diagram showing the layer structure distribution of a composite structure in some embodiments of the present application Figure 1 ;

[0023] Figure 5 is a schematic diagram showing the layer structure distribution of a composite structure in some embodiments of the present application Figure 2 ;

[0024] Figure 6 is a schematic diagram showing the layer structure distribution of a composite structure in some embodiments of the present application Figure 3 ;

[0025] Figure 7 is a schematic diagram showing the layer structure distribution of a composite structure in some embodiments of the present application Figure 4 。

[0026] In the figure:

[0027] 100, outer pipe body; 110, first closing part;

[0028] 200, inner tube body; 210, guiding channel; 220, second closing part;

[0029] 300, braided layer;

[0030] 400, annular convex ring;

[0031] 500, coating layer. Detailed implementation manners

[0032] To make the objectives, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation manners obtained by those of ordinary skill in the art without creative efforts fall within the scope protected by the present invention.

[0033] The terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so that the embodiments of this application can be implemented in an order other than those illustrated or described here, and the objects distinguished by "first", "second", etc. are usually of the same category, and do not limit the number of objects. For example, the first object can be one or multiple. In addition, "and / or" in the description and claims means at least one of the connected objects, and the character " / ", generally represents an "or" relationship between the associated objects before and after.

[0034] In the embodiments of this application, "proximal end" and "distal end" refer to the relative distances of each component from the user in the usage environment. Among them, 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".

[0035] In the related art, a guiding sheath is a medical device commonly used in the medical field, mainly used to guide other medical devices into the body cavity of a patient. The guiding sheath is usually used in interventional therapy, especially in medical operations such as endoscopy and vascular interventional therapy, and plays a crucial role. The guiding sheath provides a channel through its tubular structure, enabling other medical devices to smoothly enter the target site, thereby improving the accuracy and safety of the operation. The guiding sheath is usually inserted into the body cavity, and then other devices such as endoscopes, catheters, and needles are guided through the space it provides to complete the diagnosis and treatment operation.

[0036] The structure of a guiding sheath is usually composed of multiple layers of materials to ensure its strength, flexibility, and safety during use. Generally speaking, the structure of a guiding sheath includes an outer protective layer, a middle support layer, and an inner layer. The protective layer is generally made of a relatively thin material with a smooth surface. Its main function is to protect the guiding sheath from external physical damage during use and to facilitate insertion into the body cavity during operation. The middle layer is usually composed of a stronger material to enhance the structural rigidity of the guiding sheath and ensure that it can maintain a stable shape under a certain pressure. The inner layer is also a relatively thin structure, usually with a smooth surface, to reduce friction and ensure that other medical devices can pass through the guiding sheath smoothly.

[0037] However, although multiple protections and functions have been considered in the structural design of the guiding sheath, in actual use, since the guiding sheath needs to enter the body cavity of the patient, it is often affected by factors such as the shape of the body cavity, the operation angle, and the insertion pressure, resulting in the bending of the guiding sheath. Especially during the operation process, the bending of the guiding sheath is often inevitable. However, after the guiding sheath is bent, the structure of the inner layer may show delamination, resulting in the failure or detachment of the adhesion between the inner layer and other layers, thus affecting the function of the guiding sheath.

[0038] The delamination problem of the guiding sheath mainly stems from the braided layer in its structure. The guiding sheath is usually composed of multiple layers of composite materials, and 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, in this process, some gases often remain between the composite layers. Especially during the production process, the materials fail to completely expel the gases under high temperature or pressure, resulting in the formation of tiny bubbles or air gaps between the inner and outer layers and the braided layer.

[0039] In addition, the production process of the guiding sheath usually involves first manufacturing a long guiding sheath tube and then cutting it into the required length according to the usage requirements. During this process, the gases in the long tube body may not be expelled in time. Especially when the tube is bent or cut, the residual gases may be trapped between the middle layer and the inner layer. When the guiding sheath is bent during use, especially during the operation process, due to the tortuousness of the body cavity and the flexibility of the guiding sheath itself, the tube will undergo a certain degree of bending deformation. At this time, the gases that originally remained during the production process may be squeezed between the middle layer and the inner layer, forming bubbles or voids, thus resulting in a decrease in the adhesion force between the inner layer and the middle layer and even delamination.

[0040] 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.

[0041] Based on the above technical problems, the present invention provides a composite structure, a guide sheath and a method for preparing the composite structure.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Exemplary, combined Figure 3 , Figure 4, in a vacuum-sealed environment, the braided layer 300 is impregnated with an elastic hot-melt liquid material for curing. After a coating layer 500 is formed on the surface of the braided layer 300, it is then circumferentially compounded between the outer tube body 100 and the inner tube body 200; and / or, when the braided layer 300 is impregnated with the elastic hot-melt liquid material, the sealed environment where the braided layer 300 is located is gradually pressurized to cure the braided layer 300. After a coating layer 500 is formed on the surface of the braided layer 300, it is then circumferentially compounded between the outer tube body 100 and the inner tube body 200.

[0046] On this basis, first, the braided layer 300 is placed in a vacuum-sealed environment. In this environment, due to the lower external air pressure, the tiny air 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 molten elastic hot-melt liquid material can penetrate into the fine pores of the braided layer 300 and fill the voids that may originally exist in the braided layer 300. During this process, the fluidity of the elastic hot-melt liquid material enables it to enter various regions of the braided layer 300 and improves the overall density of the braided layer 300 to a certain extent. Eventually, a coating layer 500 will also be formed on the surface of the braided layer 300. In addition, in order to further reduce the gas residue in the braided layer 300, a step-by-step pressurization method is adopted, so that the environment in which the braided layer 300 is impregnated gradually transitions from normal pressure to a higher air pressure state. During the process of gradually increasing the pressure, the tiny air bubbles that may be trapped are further compressed or discharged under the action of the pressure, and the molten liquid material can further fill the gaps that may originally exist, making the braided layer 300 have higher integrity and density after curing.

[0047] After the above steps are completed, the braided layer 300 is cured for an appropriate time. After curing, the inside of the braided layer 300 is basically filled with the elastic hot-melt liquid material, so that during the subsequent compounding process with the outer tube body 100 and the inner tube body 200, the problem of gas retention is not likely to occur. Subsequently, the cured braided layer 300 is lifted, and the excess liquid material flows out under the action of gravity, further reducing the accumulation of the liquid material to better meet the flexibility requirements of the guiding sheath. Finally, through the die extrusion process, the treated braided layer 300 is compounded with the inner tube body 200 and the outer tube body 100 to obtain a complete composite structure.

[0048] 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 the guiding sheath less likely to experience delamination between layers during bending, thereby improving the usage effect of the guiding sheath. In addition, since the braided layer 300 has undergone processes such as vacuum exhaust, filling with an elastic hot-melt liquid material, and pressurized curing before composite, this composite structure can reduce the problem of interlayer adhesion failure caused by bubbles to a certain extent during actual use, improving the durability and reliability of the guiding sheath.

[0049] In some embodiments, after prestress is applied to both ends of the braided layer 300 and it is in a tensile state, it is immersed in an elastic hot-melt liquid material, and after covering the elastic hot-melt liquid material on the surface, the tension is released. Exemplarily, the tensile force applied to both ends of the braided layer 300 is tensile in opposite directions along the axis of the braided layer 300.

[0050] With such a setting, 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 impregnation. Specifically, both ends of the braided layer 300 give a certain prestress to the braided layer 300 itself under the action of the tensile force, making it in an axially tensile state. At this time, the braided structure of the braided layer 300 will expand to a certain extent under the tensile action, resulting in an increase in the gap between the originally closely arranged braided filaments. Subsequently, the stretched braided layer 300 is immersed in the molten elastic hot-melt liquid material. Since the braided layer 300 is in a stretched state, its internal pores are relatively large, and the molten elastic hot-melt liquid material can more smoothly penetrate into the pores of the braided layer 300 and fill the originally possible fine voids, thereby reducing the residual bubbles to a certain extent.

[0051] After the impregnation is completed, a layer of elastic hot-melt liquid material is coated on the surface of the braided layer 300, so that the material can form a uniform coverage on the overall 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 returns to its initial non-tensile state. During 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 voids of the braided layer 300 and making its structure more dense. 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 the possible tiny bubbles in the production process. In addition, after the braided layer 300 returns to its initial state, the filling method of the elastic hot-melt liquid material enables it to have better buffering ability during subsequent bending, which helps to reduce the delamination risk of the composite structure during long-term use.

[0052] In some alternative embodiments, both the inner tube body 200 and the outer tube body 100 are made of PTFE material.

[0053] In some alternative embodiments, both the inner tube body 200 and the outer tube body 100 are made of TPU material.

[0054] After such arrangement, in order to optimize the overall stability of the composite structure and to a certain extent reduce the occurrence probability of delamination, the same polymer material is selected for the inner tube body 200 and the outer tube body 100, 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 heat fusion process. Specifically, after the composite structure is prepared, it usually needs to be cut according to a specific length to meet the usage requirements of different medical devices. At the end of the cut composite structure, the inner tube body 200 and the outer tube body 100 can be melt-bonded at the end through heat fusion treatment. Since the two materials are the same, a relatively uniform molten interface can be formed during the heat fusion process, and a strong bond can be achieved after cooling, thereby forming a closed structure at the end of the composite structure.

[0055] This closed structure has certain advantages in practical applications. First of all, due to the heat fusion effect, the inner and outer layer materials at the end are effectively fused, and the end of the composite structure can reduce the delamination risk to a certain extent. Secondly, the sealed structure at the end of the composite structure can provide additional structural stability during subsequent medical operations, avoiding peeling problems caused by interlayer loosening. In addition, for the insertion force and operation smoothness of medical devices, the sealed end of the composite structure can reduce material peeling or burr phenomena that may occur during insertion, thereby helping to improve the accuracy of medical operations.

[0056] In addition, selecting PTFE or TPU as the material for 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. While TPU has good elasticity and wear resistance, and is more suitable for a guiding sheath structure that requires a certain degree of flexibility and fatigue resistance. Therefore, according to different clinical needs, selecting the appropriate material can improve the adaptability and reliability of the guiding sheath to a certain extent.

[0057] In some embodiments, after the braided layer 300 is impregnated in the elastic heat-fusible liquid material and cured, the braided layer 300 is in a tensile state with prestress applied at both ends, and then is circumferentially compounded between the outer tube body 100 and the inner tube body 200 to form a composite structure.

[0058] Exemplarily, after the formed composite structure is cut, the cut surface of the braided layer 300 shrinks inward under its own shrinkage force, and the cut surface of the outer tube body 100 follows the cut surface of the braided layer 300 to shrink inward to form a first closed portion 110, and the cut surface of the inner tube body 200 follows the cut surface of the braided layer 300 to shrink inward to form a 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 both the first closed portion 110 and the second closed portion 220 are immersion-bonded to the cut surface of the braided layer 300 through an adhesive material.

[0059] On this basis, in order to improve the overall stability of the composite structure and reduce the occurrence probability of delamination to a certain extent, during the manufacturing process of the composite structure, after the braided layer 300 is impregnated in an elastic hot-melt liquid material and cured, both ends are kept in a tension state with prestress applied, and then it is circumferentially compounded between the outer tube body 100 and the inner tube body 200 to form the final composite structure. This prestressed tension state enables the braided layer 300 to always be in a certain internal stress state after compounding, and thus can exhibit specific deformation characteristics during subsequent cutting.

[0060] When the composite structure is completed, it usually needs to be cut according to a specific length. Since prestress has been applied to the braided layer 300 before compounding, after the cutting operation, the cut surface of the braided layer 300 will shrink axially towards the center direction due to its own shrinkage force. Compared with the braided layer 300, without applying additional prestress, the cut surfaces of the inner tube body 200 and the outer tube body 100 basically remain unchanged in the initial state. However, due to the shrinkage 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 and bulge slightly inward along the shrinkage direction of the braided layer 300, thereby forming a first closed portion 110 and a second closed portion 220 at the cut end. The formation of the first closed portion 110 and the second closed portion 220 is beneficial to reducing the interlayer gap, reducing the influence of the external environment on the interlayer structure, and making the overall end shape more stable.

[0061] In addition, under the action of stress, the first closing part 110 and the second closing part 220 approach the cut surface of the braided layer 300, further strengthening the sealing 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, resulting in the possible exposure of the interlayer structure to the external environment, which in turn affects the structural stability. Therefore, medical glue is applied for dipping and bonding in the cut area, so that the first closing part 110 and the second closing part 220 can better fuse with the cut surface of the braided layer 300. The penetration of the glue enables it to enter the braided voids of the braided layer 300 and provide additional bonding force after curing, making the end sealing effect 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 guiding sheath in medical operations.

[0062] Through the above structure, after being cut, the composite structure can rely on the shrinkage 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 closing structure to a certain extent, and combined with the dipping and bonding method of medical glue, the overall end bonding strength is improved. This design helps to optimize the mechanical properties of the guiding sheath, reduce the risk of interlayer peeling, and improve the safety and stability of the medical device during clinical use.

[0063] Exemplarily, the elastic hot-melt liquid material is configured as a TPU material. The selection of this material has beneficial effects on the overall performance of the composite structure in many aspects. First of all, the TPU material has good elasticity and flexibility, so that after being impregnated and cured in the voids of the braided layer 300, it can adapt to the deformation of the guiding sheath in the bending or stressed state to a certain extent, thereby reducing the interlayer stress concentration and the possibility of delamination. In addition, the TPU material has good fluidity in the molten state, which enables the TPU to fill the pores of the braided layer 300 more fully during the impregnation process of the braided layer 300 and provide a high adhesion force after subsequent curing, making the combination between the braided layer 300 and the inner and outer tube bodies 100 closer.

[0064] In the manufacturing process of the composite structure, in a vacuum-sealed environment, when the braided layer 300 is immersed in the molten TPU liquid, due to the discharge of gas in the vacuum state, it helps the TPU to fully penetrate into the pore structure inside the braided layer 300, reducing air residue and improving the uniformity of the interlayer bonding. At the same time, curing is carried out in a gradually pressurized environment, enabling the TPU to further fill the voids of the braided layer 300 under high pressure and forming a more stable interfacial bond after curing, thereby enhancing the overall strength of the composite structure. In addition, impregnation is carried out when the braided layer 300 is in a stretched state, and after covering the surface with the TPU material, the stretching is released. This process enables 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, helping to improve the overall bonding degree between the braided layer 300 and the composite structure and reducing the possibility of interlayer slippage.

[0065] During the formation of the closed structure after the composite structure is cut, the hot-melt property of the TPU material also shows certain advantages. Since both the inner tube body 200 and the outer tube body 100 can be made of TPU material, after cutting, local heating can be used to cause the TPU material at the cut end to undergo hot-melt bonding, making the plugging effect of the first closing portion 110 and the second closing portion 220 more stable. In addition, the TPU material has good wear resistance and tear resistance, enabling the guiding sheath to maintain good structural integrity during bending and multiple uses. Therefore, in this embodiment, configuring the elastic hot-melt liquid material as TPU not only helps to improve the overall bonding performance of the composite structure, but also provides more stable physical properties during the manufacturing and use processes, thereby improving the use effect of the guiding sheath.

[0066] In some alternative embodiments, such as Figure 5 shown, along the axial direction of the guiding channel 210, a plurality of annular ridges 400 are circumferentially and spacedly fitted between the outer tube body 100 and the braided layer 300.

[0067] In some alternative embodiments, such as Figure 6 shown, along the axial direction of the guiding channel 210, a plurality of annular ridges 400 are circumferentially and spacedly fitted between the inner tube body 200 and the braided layer 300.

[0068] In some alternative embodiments, such as Figure 7 shown, along the axial direction of the guiding channel 210, a plurality of annular ridges 400 are circumferentially and spacedly wound around the braided layer 300, and a part of the annular ridge 400 is in contact with the inner wall of the outer tube body 100 and another part is in contact with the outer wall of the inner tube body 200.

[0069] On this basis, along the axial direction of the guiding channel 210, a plurality of annular ridges 400 are circumferentially spaced between the outer tube body 100 and the braided layer 300, between the inner tube body 200 and the braided layer 300, or directly on the braided layer 300. This structural design has a certain positive effect on improving the overall stability and delamination resistance of the composite structure. First, the annular ridges 400 are axially spaced, causing the composite structure to form multiple relatively independent segmented regions. When the composite structure experiences delamination in a certain segment due to external stress or other factors during use, the annular ridges 400 can act as a physical barrier, locally restricting the delamination phenomenon and reducing the likelihood of the delamination spreading axially. Even if the delamination phenomenon spreads to adjacent segments, since there are still multiple axially spaced annular ridges 400, they can still impose a certain restrictive effect on the extension of the delamination, thereby helping to reduce the risk of damage to the integrity of the composite structure.

[0070] Secondly, the setting of the annular ridges 400 not only plays a role in delamination control but also can enhance the supporting ability of the braided layer 300 to a certain extent. Since the braided layer 300 is usually made of metal or high-strength fibers, its main function is to provide radial support to prevent the composite structure from radially contracting or deforming under negative pressure or lateral forces. However, in some special application scenarios, the braided layer 300 may experience local deformation due to long-term stress or manufacturing errors, thereby affecting the stability of the composite structure. By arranging the annular ridges 400 inside the braided layer 300, an additional supporting effect can be provided in the circumferential direction, making the radial form 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 within the design range.

[0071] In addition, the material of the annular ridges 400 can be selected according to specific requirements. For example, it can be made of TPU, metal, or other polymer materials with appropriate rigidity and elasticity. When the annular ridges 400 are made of TPU or other elastic materials, they can adapt to a certain range of deformation under external forces, thereby enhancing the flexibility of the composite structure and reducing the impact of rigid mutations on the overall mechanical properties. When the annular ridges 400 are made of metal materials, the overall strength of the structure can be further improved, enabling the composite structure to have better shape retention ability under high-pressure environments. During the manufacturing process, the annular ridges 400 can be installed by means of molding, injection molding, or direct embedding, and can be designed with different distribution spacings and sizes to meet the application requirements of guiding sheaths with different diameters and lengths. Generally speaking, by setting a plurality of annular ridges 400 inside the composite structure, the delamination resistance of the composite structure can be effectively improved, the supporting performance of the braided layer 300 can be enhanced, and the mechanical characteristics of the guiding sheath can be optimized to a certain extent, thereby improving its use reliability in medical and other fields.

[0072] In some embodiments, the outer surface and / or the inner surface of the impregnated braided layer 300 form uneven surfaces (not shown in the figure) under the action of air drying, and the uneven surfaces are used to closely fit with the inner wall of the outer tube body 100 or the outer wall of the inner tube body 200. Exemplarily, the uneven surface can be a convex surface or a concave surface.

[0073] After the braided layer 300 is impregnated with the elastic hot-melt liquid material, its outer surface and / or inner surface form uneven surfaces after air drying. This structural design has a certain positive effect on improving the interfacial bonding strength of the composite structure. Specifically, during the process of impregnating the braided layer 300 with the elastic hot-melt liquid material, the liquid material will cover the surface of the metal wires of the braided layer 300 and fill part of the braiding gaps. During the air drying process, due to the action of the air flow, the incompletely cured elastic hot-melt liquid material may flow unevenly along the surface of the metal wires, resulting in an uneven surface morphology after final curing. The formation of such uneven surfaces can, on the one hand, reduce the possible excessive liquid accumulation on the surface of the braided layer 300, thereby avoiding the formation of an overly thick or uneven coating, which may affect the overall mechanical properties of the composite structure; on the other hand, the existence of the uneven surfaces 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 enhancing the interfacial bonding strength.

[0074] When the braided layer 300 is combined with the inner tube body 200 or the outer tube body 100, due to the existence of the uneven surfaces on the surface of the braided layer 300, the contact mode with the adjacent layer will change from the original smooth surface contact to a combined mode of multi-point contact and interlocking contact. This contact mode not only increases the mechanical interlocking effect per unit area but also can improve the interfacial friction to a certain extent, thereby being beneficial to enhancing the adhesion stability between the composite structures and reducing the delamination risk that may occur during long-term use. In addition, when subjected to complex mechanical actions such as external bending, stretching, or compression, the uneven surface structure can produce a certain stress dispersion effect locally, avoiding stress concentration on a single plane, thereby enhancing the overall durability and anti-peeling performance of the composite structure.

[0075] During the manufacturing process, the specific morphology and distribution of the uneven surfaces can be adjusted by controlling parameters such as the air drying intensity, wind direction, and the initial coating thickness of the impregnating liquid to adapt to the guiding sheath designs with different specifications and application requirements. Therefore, by forming uneven surfaces on the surface of the braided layer 300 and utilizing their close fitting effect with the inner tube body 200 or the outer tube body 100, the interfacial bonding characteristics of the composite structure can be optimized to a certain extent, enhancing its mechanical properties and use stability.

[0076] Exemplarily, the wall thickness of the inner tube body 200 is greater than the wall thickness of the outer tube body 100, so as to keep the inner tube body 200 smooth and make the guiding sheath easier to bend during actual use.

[0077] In a second aspect, in combination with Figures 1 to 7 , the present application also provides a guiding sheath, including the composite structure of the first aspect.

[0078] In a third aspect, the present invention provides a method for preparing a composite structure for preparing the composite structure of the first aspect, including the following steps:

[0079] Fill the elastic hot-melt liquid material into a sealed container, place the braided layer 300 in the blank area above the elastic hot-melt liquid material in the container, and at the same time adjust the air pressure in the container to make the container in a negative pressure environment;

[0080] Immerse the braided layer 300 into the elastic hot-melt liquid material, and then continue to adjust the air pressure in the container to make the container in a positive pressure environment, so that the elastic hot-melt liquid material fills the periphery of the braided layer 300 and at the same time extrudes the air in the braided layer 300;

[0081] Lift the braided layer 300 impregnated with the elastic hot-melt liquid material to the blank area in the container, so that the excess elastic hot-melt liquid material on the surface of the braided layer 300 drips off;

[0082] Apply wind force to the braided layer 300 in the blank area in the container to accelerate the curing of the braided layer 300 impregnated with the elastic hot-melt liquid material under the air-drying effect;

[0083] Put the braided layer 300 impregnated with the elastic hot-melt liquid material, the inner tube body 200 and the outer tube body 100 into a mold, and form the composite structure of the first aspect through an extrusion process.

[0084] It should be noted that in this article, the term "including", "comprising" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "including one..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0085] In addition, it should be pointed out 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 also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0086] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily conceive of changes or substitutions, which should all be covered within 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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