PTFE (Polytetrafluoroethylene) thermal shrinkage mandrel for conduit

Abstract

The utility model discloses a polytetrafluoroethylene (PTFE) thermal shrinkage mandrel for a conduit, which comprises a metal mandrel and a PTFE thermal shrinkage tube, the PTFE thermal shrinkage tube is wrapped outside the metal mandrel in a thermal shrinkage manner, the PTFE thermal shrinkage tube and the metal mandrel are coaxially arranged, the outer wall of the PTFE thermal shrinkage tube is a smooth surface, the inner wall of the PTFE thermal shrinkage tube is a joint surface, and the outer wall of the PTFE thermal shrinkage tube and the metal mandrel are integrally formed. The PTFE heat shrink tube is tightly attached to the outer wall of the metal mandrel through the joint face. The PTFE heat shrink tube is thermally shrunk inwards in the radial direction at the two ends of the metal core shaft to form anti-falling parts, and the anti-falling parts wrap the end portions of the metal core shaft in the annular direction. The PTFE guide pipe can be repeatedly used, the service life is prolonged, the stability is high, the PTFE outer layer cannot fall off, and the production and processing cost of the guide pipe is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to medical catheter processing technical field, especially relate to a PTFE heat shrink mandrel for catheter. BACKGROUND

[0002] In the production process of medical catheter, the mandrel is arranged in the inside of the catheter to ensure the inner diameter of the catheter, and the mandrel needs to be axially withdrawn after production is completed, and in order to easily withdraw the mandrel from the catheter, a layer of PTFE coating is usually sprayed on the surface of the mandrel, and the PTFE coating is used to reduce the friction of the outer surface of the mandrel, but this way of spraying PTFE coating on the outer surface of the mandrel has a defect: the mandrel coated with PTFE coating is prone to coating falling off during catheter processing and production, thereby affecting the quality of the produced catheter, and usually the mandrel coated with PTFE coating is used for 5-10 times, and then the PTFE coating starts to fall off, and usually the mandrel coated with PTFE coating is used for 20 times, and then the PTFE coating falls off seriously, so that the mandrel cannot be used, and the surface of the mandrel needs to be cleaned to re-spray new PTFE coating, so as to ensure the thickness consistency of the PTFE coating on the surface of the mandrel, which increases the cost of catheter manufacturing, and needs to be improved. SUMMARY

[0003] The utility model discloses a PTFE heat shrink mandrel for catheter, which has the effects of being reusable multiple times, prolonging service life, being stable and not prone to PTFE outer layer falling off, and reducing catheter production and processing cost.

[0004] The above technical purpose of the utility model is achieved by the following technical scheme: a PTFE heat shrink mandrel for catheter, comprising a metal mandrel and a PTFE heat shrink tube, the PTFE heat shrink tube is heat shrunk and wrapped outside the metal mandrel, the PTFE heat shrink tube is coaxially arranged with the metal mandrel, the outer wall of the PTFE heat shrink tube is a smooth surface, the inner wall of the PTFE heat shrink tube is a joint surface, and the PTFE heat shrink tube is tightly combined with the outer wall of the metal mandrel through the joint surface.

[0005] The PTFE heat shrink tube is heat shrunk to form an anti-falling part radially inward at both ends of the metal mandrel, and the anti-falling part is annularly wrapped around the end of the metal mandrel.

[0006] By adopting the technical scheme, the PTFE heat shrink tube is coaxially sleeved outside the metal mandrel during assembly, while ensuring that there is a PTFE heat shrink tube allowance at both ends of the metal mandrel, then the PTFE heat shrink tube is uniformly heated as a whole, so that the PTFE heat shrink tube is heat shrunk and wrapped radially inward outside the metal mandrel, and since the PTFE heat shrink tube portions at both ends of the metal mandrel are heat shrunk and deformed inward without the blockage of the metal mandrel, the PTFE heat shrink tube portions at both ends are heat shrunk and wrapped around the two ends of the metal mandrel to form anti-disengagement portions, the joint surface of the inner wall of the PTFE heat shrink tube is used to realize close adhesion to the outer surface of the metal mandrel, so as to prevent the PTFE heat shrink tube from rotating relative to the metal mandrel, meanwhile, the anti-disengagement portions at both ends of the PTFE heat shrink tube can effectively prevent the PTFE heat shrink tube from axially sliding relative to the metal mandrel, and the smooth surface of the outer wall of the PTFE heat shrink tube can be used to realize that the catheter is quickly separated from the outer wall of the PTFE heat shrink tube during catheter processing, which is different from the way of spraying a PTFE coating outside the mandrel on the market, the way of heat shrink wrapping the PTFE heat shrink tube outside the outer surface of the metal mandrel is adopted, which can realize the purpose of multiple uses without PTFE outer layer falling off, by reducing the repeated spraying of the PTFE coating, the cost of catheter processing can be effectively reduced, and the efficiency of catheter processing is improved, and the catheter has the effects of multiple repeated use, long service life, high stability without PTFE outer layer falling off, and reduced catheter production and processing cost.

[0007] The metal mandrel is made of stainless steel.

[0008] By adopting the technical scheme, the metal mandrel made of stainless steel has high corrosion resistance, and has good heat conduction effect, which is beneficial to prolong the service life of the mandrel and improve the heat shrink speed and uniformity of the PTFE heat shrink tube.

[0009] The metal mandrel is made of stainless steel.

[0010] By adopting the technical scheme, the metal mandrel made of stainless steel has high corrosion resistance, and has good heat conduction effect, which is beneficial to prolong the service life of the mandrel and improve the heat shrink speed and uniformity of the PTFE heat shrink tube.

[0011] The metal mandrel is made of stainless steel.

[0012] By adopting the technical scheme, the metal mandrel made of stainless steel has high corrosion resistance, and has good heat conduction effect, which is beneficial to prolong the service life of the mandrel and improve the heat shrink speed and uniformity of the PTFE heat shrink tube.

[0013] The further setting of the utility model discloses: the outer wall of metal core shaft corresponds the sanding layer that is formed to the joint surface.

[0014] Through adopting above-mentioned technical scheme, the outer surface of metal core shaft is sanded to obtain sanding layer, can effectively improve the friction between the joint surface of metal core shaft and PTFE heat shrink tube, improve the rotation stopping effect between PTFE heat shrink tube and metal core shaft.

[0015] The further setting of the utility model discloses: the metal core shaft is equipped with tear structure to tear PTFE heat shrink tube.

[0016] Through adopting above-mentioned technical scheme, when the utility model is repeatedly used for many times, the surface of PTFE heat shrink tube outside metal core shaft can be abraded due to the stripping of catheter, when the abrasion reaches critical value, PTFE heat shrink tube needs to be stripped from metal core shaft, at this time, the tear structure can be used to quickly strip PTFE heat shrink tube from metal core shaft.

[0017] The further setting of the utility model discloses: the tear structure includes several tear fiber filaments arranged on the surface of metal core shaft.

[0018] Through adopting above-mentioned technical scheme, the operator can pull tear fiber filament radially outward, tear PTFE heat shrink tube on the surface of metal core shaft using tear fiber filament, that is, PTFE heat shrink tube can be more easily peeled off from the surface of metal core shaft.

[0019] The further setting of the utility model discloses: the outer wall of metal core shaft is equipped with several strip-shaped installation grooves along the axial direction, the tear fiber filament is pre-buried in corresponding strip-shaped installation groove, and when PTFE heat shrink tube is heat-shrunk and wrapped outside metal core shaft, one side of tear fiber filament close to the opening end of strip-shaped installation groove is supported with the inner wall of PTFE heat shrink tube.

[0020] Through adopting above-mentioned technical scheme, tear fiber filament is pre-buried in corresponding strip-shaped installation groove during assembly, then PTFE heat shrink tube is heat-shrunk and wrapped outside metal core shaft pre-buried with tear fiber filament, and assembly can be completed.

[0021] The further setting of the utility model discloses: the outer wall of metal core shaft is equipped with helical installation groove along the length direction, the tear fiber filament is pre-buried in helical installation groove, and when PTFE heat shrink tube is heat-shrunk and wrapped outside metal core shaft, one side of tear fiber filament close to the opening end of helical installation groove is supported with the inner wall of PTFE heat shrink tube.

[0022] By adopting the above technical scheme, when the outwardly tearing fiber is torn, the tearing fiber embedded in the spiral installation groove can be used to realize spiral cutting of the PTFE heat-shrinkable tube, and the PTFE heat-shrinkable tube can be more easily peeled from the surface of the metal mandrel.

[0023] The utility model discloses further provide that: the material of tearing fiber is metal material quality with tenacity.

[0024] In conclusion, the utility model has the following beneficial effects:

[0025] The PTFE heat-shrinkable tube is uniformly heated as a whole, so that the PTFE heat-shrinkable tube is radially inwardly heat-shrunk on the metal mandrel, and the PTFE heat-shrinkable tube is radially inwardly heat-shrunk on the metal mandrel and forms the anti-disengagement part at the two ends of the metal mandrel, the metal mandrel is not blocked when the PTFE heat-shrinkable tube is radially inwardly heat-shrunk at the two ends of the metal mandrel, the PTFE heat-shrinkable tube is radially inwardly heat-shrunk on the two ends of the metal mandrel and forms the anti-disengagement part, the inner wall of the PTFE heat-shrinkable tube is tightly attached to the outer surface of the metal mandrel by the joint surface, the PTFE heat-shrinkable tube is prevented from rotating relative to the metal mandrel, the anti-disengagement part at the two ends of the PTFE heat-shrinkable tube can effectively prevent the PTFE heat-shrinkable tube from axially sliding relative to the metal mandrel, the smooth surface of the outer wall of the PTFE heat-shrinkable tube can be used to quickly separate the catheter from the outer wall of the PTFE heat-shrinkable tube during catheter processing, the utility model uses the PTFE heat-shrinkable tube to heat-shrink on the outer surface of the metal mandrel, which can be used repeatedly without PTFE outer layer falling off, the repeated spraying of the PTFE coating is reduced, the cost of catheter processing is effectively reduced, the efficiency of catheter processing is improved, the catheter can be repeatedly used to prolong the service life, the stability is high, the PTFE outer layer does not fall off, and the production and processing cost of the catheter is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is the overall structure diagram of the first embodiment of the utility model.

[0027] Figure 2 It is the longitudinal section view of the utility model Figure 1 .

[0028] Figure 3 It is the local enlarged view of A area in the utility model Figure 2 .

[0029] Figure 4This is a structural diagram of a metal mandrel in a specific embodiment of the present invention, in which the torn fiber filaments are pre-embedded in a strip-shaped mounting groove.

[0030] Figure 5 This is a structural diagram of a metal mandrel in a specific embodiment three of this utility model, in which the torn fiber filaments are pre-embedded in a spiral new installation groove.

[0031] In the diagram: 1. Metal mandrel; 11. Rounded corner; 12. Frosted layer; 13. Strip mounting groove; 14. Spiral mounting groove; 2. PTFE heat shrink tubing; 21. Smooth surface; 22. Joint surface; 23. Anti-detachment part; 3. Tear fiber filament; 31. Traction head. Detailed Implementation

[0032] The present invention will be further described below with reference to the accompanying drawings. Specific Implementation Example 1

[0034] A type of PTFE heat-shrink mandrel for catheters, such as Figure 1 As shown, it includes a metal mandrel 1 and a PTFE heat shrink tube 2. The PTFE heat shrink tube 2 is heat-shrinked and wrapped around the metal mandrel 1. The PTFE heat shrink tube 2 is coaxially arranged with the metal mandrel 1, and the outer wall of the PTFE heat shrink tube 2 is a smooth surface 21, and the inner wall of the PTFE heat shrink tube 2 is a mating surface 22. The PTFE heat shrink tube 2 is tightly attached to the outer wall of the metal mandrel 1 through the mating surface 22. The PTFE heat shrink tube 2 has anti-detachment parts 23 formed radially inward at both ends of the metal mandrel 1, and the anti-detachment parts 23 are circumferentially covered around the ends of the metal mandrel 1.

[0035] like Figures 1-3 As shown, the metal mandrel 1 is made of stainless steel. Stainless steel has high corrosion resistance and good thermal conductivity, which helps extend the service life of the mandrel and improves the heat shrinking speed and uniformity of the PTFE heat shrink tubing 2. The perimeter of both ends of the metal mandrel 1 is rounded 11, which can effectively prevent the PTFE heat shrink tubing 2 from being damaged due to excessive stress extrusion at the ends of the metal mandrel 1 during the heat shrinking process. The outer wall thickness of the PTFE heat shrink tubing 2 is the same, and the thickness of the PTFE heat shrink tubing 2 formed on the outer wall of the metal mandrel 1 is maintained between 0.1-10mm. The uniform thickness of the PTFE heat shrink tubing 2 is beneficial to the uniformity of the inner diameter of the conduit during production. At the same time, the PTFE heat shrink mandrel with the corresponding thickness and diameter can be selected according to the actual needs of the conduit production.

[0036] The basic working principle of the utility model is that a layer of PTFE heat shrink tube 2 is wrapped on the outer surface of the metal core shaft 1, meanwhile, the PTFE heat shrink tube 2 is formed with anti-off portions 23 along the radial direction inwardly at both ends of the metal core shaft 1, during assembly, the PTFE heat shrink tube 2 is coaxially sleeved on the outer surface of the metal core shaft 1, meanwhile, the PTFE heat shrink tube 2 is ensured to have a surplus at both ends of the metal core shaft 1, then the PTFE heat shrink tube 2 is uniformly heated as a whole, so that the PTFE heat shrink tube 2 is wrapped on the outer surface of the metal core shaft 1 along the radial direction inwardly, meanwhile, since the PTFE heat shrink tube 2 at both ends of the metal core shaft 1 is deformed inwardly without the block of the metal core shaft 1, the PTFE heat shrink tube 2 is wrapped on both ends of the metal core shaft 1 along the radial direction inwardly and forms the anti-off portions 23, the joint surface 22 of the inner wall of the PTFE heat shrink tube 2 is used to realize the close adhesion with the outer surface of the metal core shaft 1, so that the PTFE heat shrink tube 2 is prevented from rotating relative to the metal core shaft 1, meanwhile, the anti-off portions 23 at both ends of the PTFE heat shrink tube 2 can effectively prevent the PTFE heat shrink tube 2 from axially sliding relative to the metal core shaft 1, during the processing of the catheter, the smooth surface 21 of the outer wall of the PTFE heat shrink tube 2 can realize the quick separation of the catheter from the outer wall of the PTFE heat shrink tube 2, different from the mode of spraying the PTFE coating on the outer surface of the core shaft in the market, the utility model adopts the mode of wrapping the PTFE heat shrink tube 2 on the outer surface of the metal core shaft 1, so that the PTFE outer layer can not be separated after multiple uses, through reducing the repeated spraying of the PTFE coating, the cost of the catheter processing can be effectively reduced, the efficiency of the catheter processing is improved, the catheter has the effects of multiple repeated use, long service life, high stability, no separation of the PTFE outer layer and low catheter production and processing cost. Specific embodiment two

[0038] A PTFE heat shrink core shaft for a catheter, such as Figure 4As shown, the difference between the embodiment and the specific embodiment one is that the outer wall of the metal mandrel 1 is formed with the frosted layer 12 corresponding to the joint surface 22, the outer surface of the metal mandrel 1 is frosted to obtain the frosted layer 12, the friction between the metal mandrel 1 and the joint surface 22 of the PTFE heat-shrinkable tube 2 can be effectively improved, and the rotation stopping effect between the PTFE heat-shrinkable tube 2 and the metal mandrel 1 is improved; the metal mandrel 1 is provided with a tearing structure for tearing the PTFE heat-shrinkable tube 2, when the utility model is repeatedly used for many times, the surface of the PTFE heat-shrinkable tube 2 outside the metal mandrel 1 is abraded due to the demolding of the catheter, when the abrasion amount reaches a critical value, the PTFE heat-shrinkable tube 2 needs to be detached from the metal mandrel 1, at this time, the tearing structure can be used to quickly detach the PTFE heat-shrinkable tube 2 from the metal mandrel 1; the tearing structure comprises a plurality of tearing fiber filaments 3 arranged on the surface of the metal mandrel 1, the material of the tearing fiber filament 3 is a metal material with toughness, an operator can pull the tearing fiber filament 3 radially outward, and the PTFE heat-shrinkable tube 2 on the surface of the metal mandrel 1 is torn by the tearing fiber filament 3, so that the PTFE heat-shrinkable tube 2 can be more easily peeled off from the surface of the metal mandrel 1; a plurality of strip-shaped mounting grooves 13 are formed in the outer wall of the metal mandrel 1 in the axial direction, the tearing fiber filament 3 is pre-embedded in the corresponding strip-shaped mounting groove 13, and when the PTFE heat-shrinkable tube 2 is heat-shrunk and wrapped outside the metal mandrel 1, one side of the tearing fiber filament 3 close to the opening end of the strip-shaped mounting groove 13 is supported and matched with the inner wall of the PTFE heat-shrinkable tube 2, during assembly, the tearing fiber filament 3 is pre-embedded in the corresponding strip-shaped mounting groove 13, and then the PTFE heat-shrinkable tube 2 is heat-shrunk and wrapped outside the metal mandrel 1 pre-embedded with the tearing fiber filament 3, so that the assembly is completed; in the embodiment, at least one end of the tearing fiber filament 3 is extended with a traction head 31, when the PTFE heat-shrinkable tube 2 is wrapped outside the metal mandrel 1, the traction head 31 is partially exposed outside the strip-shaped mounting groove 13, so that an operator can pull the tearing fiber filament 3 to tear the PTFE heat-shrinkable tube 2 through the traction head 31.

[0039] The embodiment is consistent with other structures of the specific embodiment one, and details are not repeated here. Specific embodiment three

[0041] A PTFE heat-shrinkable mandrel for a catheter, as shown in the figure, Figure 5 The difference between the embodiment and the specific embodiment two is that the outer wall of the metal mandrel 1 is formed with the spiral mounting groove 14 in the length direction, the tearing fiber filament 3 is pre-embedded in the spiral mounting groove 14, and when the PTFE heat-shrinkable tube 2 is heat-shrunk and wrapped outside the metal mandrel 1, one side of the tearing fiber filament 3 close to the opening end of the spiral mounting groove 14 is supported and matched with the inner wall of the PTFE heat-shrinkable tube 2, so that when the tearing fiber filament 3 is pulled outward, the tearing fiber filament 3 pre-embedded in the spiral mounting groove 14 can realize spiral cutting of the PTFE heat-shrinkable tube 2, and the PTFE heat-shrinkable tube 2 can be more easily peeled off from the surface of the metal mandrel 1.

[0042] The embodiment is consistent with other structures of the second embodiment, and will not be described here.

[0043] The above is only the preferred embodiment of the present application, so equivalent changes or modifications made according to the structure, features and principles described in the patent application range of the present application are included in the patent application range of the present application.

Claims

1. A PTFE heat-shrink mandrel for catheters, characterized by: The metal mandrel (1) and the PTFE heat shrink tube (2) are coaxially arranged, the outer wall of the PTFE heat shrink tube (2) is provided with a smooth surface (21), the inner wall of the PTFE heat shrink tube (2) is provided with an engaging surface (22), and the PTFE heat shrink tube (2) is tightly combined with the outer wall of the metal mandrel (1) through the engaging surface (22). The PTFE heat shrink tube (2) is radially inwardly heat shrunk to form an anti-disengagement part (23) at both ends of the metal mandrel (1), and the anti-disengagement part (23) is circumferentially wrapped around the end of the metal mandrel (1).

2. A PTFE heat-shrink mandrel for use in a catheter according to claim 1, characterized in that: The material of the metal mandrel (1) is stainless steel.

3. A PTFE heat-shrink mandrel for use in a catheter according to claim 1, characterized in that: The periphery of the end surface of the metal mandrel (1) is provided with a rounded corner (11).

4. A PTFE heat-shrink mandrel for use in a catheter according to claim 1, characterized in that: The thickness of the outer wall of the PTFE heat shrink tube (2) is the same, and the thickness of the PTFE heat shrink tube (2) heat shrunk to the outer wall of the metal mandrel (1) is kept between 0.1-10mm.

5. A PTFE heat-shrink mandrel for use in a catheter according to claim 1, characterized in that: The outer wall of the metal mandrel (1) is provided with a frosted layer (12) corresponding to the engaging surface (22).

6. A PTFE heat-shrink mandrel for use in a catheter according to claim 1, characterized in that: The metal mandrel (1) is provided with a tearing structure for tearing the PTFE heat shrink tube (2).

7. A PTFE heat-shrink mandrel for use in a catheter according to claim 6, characterized in that: The tearing structure includes a plurality of tearing fiber filaments (3) arranged on the surface of the metal mandrel (1).

8. A PTFE heat-shrink mandrel for use in a catheter according to claim 7, characterized in that: A plurality of strip-shaped installation grooves (13) are axially arranged on the outer wall of the metal mandrel (1), the tearing fiber filaments (3) are pre-embedded in the strip-shaped installation grooves (13), and when the PTFE heat shrink tube (2) is heat shrunk around the metal mandrel (1), the side of the tearing fiber filaments (3) close to the opening end of the strip-shaped installation grooves (13) is supported by the inner wall of the PTFE heat shrink tube (2).

9. A PTFE heat-shrink mandrel for use in a catheter according to claim 7, characterized in that: The outer wall of the metal mandrel (1) is provided with a spiral-shaped installation groove (14) along the length direction, the tearing fiber filaments (3) are pre-embedded in the spiral-shaped installation groove (14), and when the PTFE heat shrink tube (2) is heat shrunk around the metal mandrel (1), the side of the tearing fiber filaments (3) close to the opening end of the spiral-shaped installation groove (14) is supported by the inner wall of the PTFE heat shrink tube (2).

10. A PTFE heat-shrink mandrel for use in a catheter according to claim 7, characterized in that: The material of the tearing fiber filaments (3) is a metal material with toughness.

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