Medical carbon fiber composite tube and preparation method thereof

Abstract

The invention relates to a composite pipe for medical equipment, which is of a three-layer composite structure and comprises a lining layer, a reinforcing layer and an outer coating layer, the lining layer is a fluorine-containing plastic pipe, the reinforcing layer is a carbon fiber woven mesh layer or a wire winding layer, and the outer coating layer is a thermoplastic plastic pipe; the three-layer composite structure is heated and shrunk through the expansion pipe, so that the inner and outer layer materials are fused, and the carbon fiber layer is fixedly bonded in the middle. By adopting the composite pipe prepared by the invention, the axial strength of the pipe can be improved on the premise of keeping the flexibility of the pipe.

Description

Technical Field

[0001] The present invention relates to a medical composite tube and a preparation method thereof, and particularly to a medical carbon fiber composite tube and a preparation method thereof. Background Art

[0002] Interventional therapy has become one of the main methods for treating cardiovascular diseases globally. In order to enable interventional devices to reach the expected site quickly and accurately, it is necessary to use guiding devices to establish channels, such as catheter sheaths, guiding catheters, support catheters, and microcatheters. Therefore, medical catheters play an important role in minimally invasive interventional therapy, especially in some complex interventional surgeries. Braided tubes have excellent support, flexibility, and bending resistance, and are widely used in the production and processing technology of medical catheters and sheath tubes to ensure the safety and effectiveness of the channels.

[0003] The braided net in the braided tube is generally woven from metal materials such as SS304, which has excellent support, torque resistance, and anti-folding properties, but its flexibility is slightly poor and it cannot be used at the distal end of the catheter. In order to minimize damage to the human body and prevent situations such as wire leakage at the edge of the braided tube, a polymer tube without a braided structure is welded at the head end, but the mechanical strength of this polymer tube is insufficient, and the tube wall is prone to wear and rupture when transporting metal pipe network structures such as nickel-titanium stents, metal filters, and arrestors, resulting in the failure of the device to be used and clinical adverse events. Summary of the Invention

[0004] To solve the problems raised in the above background art, the present invention provides the following technical solutions: A composite pipe for medical devices, which is a three-layer composite pipe structure, including an inner liner layer, a reinforcement layer, and an outer covering layer from inside to outside. The outer covering layer includes an expansion tube, and the expansion tube makes the inner liner layer, the reinforcement layer, and the outer covering layer fit together and fixes the reinforcement layer. The reinforcement layer is a carbon fiber braided net layer or a wire winding layer.

[0005] The surface of the inner liner layer is a rough surface. The inner liner layer is an inner liner extrusion tube made by co-extrusion or layer extrusion of one or two of polytetrafluoroethylene (PTFE), perfluoroethylene propylene (FEP), and soluble polytetrafluoroethylene (PFA). The thickness of the inner liner layer is 0.02 - 1.0 mm.

[0006] The thickness of the reinforcement layer is 0.01 - 0.50 mm, and the tensile strength of the carbon fiber in the reinforcement layer is not less than 3500 MPa, and the wire diameter is less than 10 μm.

[0007] The outer covering layer further includes an outer covering extrusion tube, and the outer covering extrusion tube is filled between the inner liner layer, the reinforcement layer, and the expansion tube.

[0008] The thickness of the outer covering layer is 0.02 - 1.0 mm, and the materials of the outer covering extrusion tube and the expansion tube are polyamide (PA), polyether block polyamide (PEBAX), polyurethane (PU), polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP) or polyolefin (PO).

[0009] The preparation method of the composite pipe for the medical device includes the following steps: Step 1, the outer surface of the inner lining extrusion tube is first treated by plasma etching to increase the surface roughness and reduce the surface energy; Step 2, the carbon fiber is directly woven or wound on the surface of the treated inner lining extrusion tube; Step 3, if the outer covering layer (3) only includes the expansion tube, perform Steps 4 to 5; if the outer covering layer (3) includes the expansion tube and the outer covering extrusion tube, perform Steps 6 to 7; Step 4, sleeving the expansion tube outside the inner lining extrusion tube with the carbon fiber; Step 5, heating to shrink the expansion tube to bond the inner lining layer (1), the strengthening layer (2) and the expansion tube together; Step 6, sleeving the outer covering extrusion tube and the expansion tube outside the inner lining extrusion tube with the carbon fiber from inside to outside in sequence; Step 7, melting the outer covering extrusion tube to fuse the inner lining layer (1), the strengthening layer (2) and the expansion tube together.

[0010] In Step 1, the plasma etching treatment uses air, the treatment time is 100 - 1000 s, and the power is 300 - 600 W.

[0011] In Step 2, each carbon fiber bundle for carbon fiber weaving or winding has 20 - 500 filaments, and the pitch is 0.5 - 5 mm.

[0012] The heating temperature in Step 5 and Step 7 is 200 - 360 °C.

[0013] The beneficial effects of the present invention are as follows: For the composite pipe with carbon fiber as the intermediate layer, while improving the axial strength of the pipe, the pipe is softer than the one with a metal mesh layer. The inner lining layer uses a fluorine-containing plastic pipe, which can improve the wear resistance of the composite pipe and reduce the friction coefficient, facilitating the pushing and recovery of the metal pipe network structure product. The plasma etching treatment of the fluorine-containing plastic pipe is green and environmentally friendly, does not introduce other impurities, reduces the surface energy of the material, and is beneficial to improving the composite bonding strength of the composite pipe. By using the method of heat-shrinkable expansion tube, the three-layer materials are bonded together, or the extrusion tube of the outer covering layer is melted to fuse the three-layer materials together, avoiding the use of adhesives or fillers for composite. Description of the Drawings

[0014] Figure 1 Schematic structural diagram of the present invention; In the figure: 1, inner lining layer; 2, reinforcing layer; 3, outer covering layer. Embodiment

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention. Embodiment

[0016] A medical composite tube has an inner diameter of 0.6 mm and an outer diameter of 0.7 mm, and from the inside outwards, it is successively a PFA inner lining layer, a carbon fiber braided mesh layer, and a PEBAX outer covering layer. The thicknesses of the PFA inner lining layer, the carbon fiber braided mesh layer, and the PEBAX outer covering layer are 0.02 mm, 0.01 mm, and 0.02 mm respectively.

[0017] It is obtained by the following steps: The PFA inner lining tube with an inner diameter of 0.6 mm and a wall thickness of 0.02 mm is treated by plasma in an air atmosphere at a power of 600 W for 100 s; then a carbon fiber mesh layer is woven outside the inner lining tube by a weaving machine. The selected carbon fiber has a tensile strength of about 4000 MPa, a wire diameter of about 6 μm, about 50 wires per strand, a total of 8 strands, and is woven in a 1-over-1 weaving method with a pitch of 1.2 mm; a PEBAX expansion tube with an inner diameter of 0.7 mm is put on the tube and heat-treated at 200 °C to make the PEBAX expansion tube shrink and cover on the inner lining tube. Embodiment

[0018] A medical composite tube has an inner diameter of 1.0 mm and an outer diameter of 1.2 mm, and from the inside outwards, it is successively a PTFE inner lining layer, a carbon fiber braided mesh layer, and a PTFE outer covering layer. The thicknesses of the PTFE inner lining layer, the carbon fiber braided mesh layer, and the PTFE outer covering layer are 0.04 mm, 0.02 mm, and 0.04 mm respectively.

[0019] It is obtained by the following steps: The PTFE inner lining tube with an inner diameter of 1.0 mm and a wall thickness of 0.04 mm is treated by plasma in an air atmosphere at a power of 400 W for 1000 s; then a carbon fiber mesh layer is woven outside the inner lining tube by a weaving machine. The selected carbon fiber has a tensile strength of about 4000 MPa, a wire diameter of about 6 μm, about 200 wires per strand, a total of 8 strands, and is woven in a 1-over-1 weaving method with a pitch of 2.0 mm; a PTFE expansion tube with an inner diameter of 1.2 mm is put on the tube and heat-treated at 360 °C to make the PTFE expansion tube shrink and cover on the inner lining tube. Example

[0020] A medical composite tube with an inner diameter of 2.0 mm and an outer diameter of 2.3 mm. From the inside to the outside, it comprises an inner lining layer extruded from PTFE and PFA, a carbon fiber woven mesh layer and a PA outer covering layer. The thicknesses of the inner lining layer, the carbon fiber woven mesh layer and the PA outer covering layer are 0.06 mm, 0.03 mm and 0.06 mm respectively.

[0021] The preparation was carried out by the following steps: An inner liner tube with a wall thickness of 2.0 mm and an inner diameter of 0.06 mm and PTFE and PFA extruded in layers was treated with plasma in an air atmosphere at a power of 600 W for 500 s; then a carbon fiber mesh layer was weaved on the outside of the inner liner tube using a braiding machine, and the carbon fiber had a tensile strength of about 4000 MPa, a wire diameter of about 6 μm, about 100 wires per strand, a total of 16 strands, and a 1-press-1 braiding method with a pitch of 3.0 mm for wrapping and braiding; a PA outer coating and a PO expansion tube were coated on the outer sleeve of the tube, and heated at 240°C to shrink the PO expansion tube and melt the PA on the inner liner tube to fuse the three layers of material together. Example

[0022] A medical composite tube has an inner diameter of 5.0 mm and an outer diameter of 8.6 mm. From the inside to the outside, it comprises an inner lining layer extruded from a mixture of FEP and PFA, a carbon fiber winding layer and a FEP outer covering layer. The thicknesses of the inner lining layer, the carbon fiber winding layer and the FEP outer covering layer are 1.0 mm, 0.5 mm and 0.3 mm respectively.

[0023] The preparation was carried out by the following steps: An inner liner tube with a wall thickness of 5.0mm and an inner diameter of 1.0mm and a mixed extrusion of FEP and PFA is treated with plasma in an air atmosphere at a power of 500W for 200s; then, carbon fiber with a tensile strength of about 3500MPa, a wire diameter of about 5μm, and about 500 wires per strand are selected and wound on the inner liner tube; an FEP expansion tube is installed on the outer sleeve of the tube and heated at 220℃ to shrink the FEP expansion tube and cover the inner liner tube. Example

[0024] A medical composite tube has an inner diameter of 6.0 mm and an outer diameter of 9 mm. From the inside to the outside, it comprises a PFA lining layer, a carbon fiber woven mesh layer and a PU outer covering layer. The thicknesses of the inner lining layer, the carbon fiber woven mesh layer and the PU outer covering layer are 0.3 mm, 0.2 mm and 1.0 mm respectively.

[0025] The preparation was carried out by the following steps: The PFA inner liner tube with a wall thickness inner diameter of 6.0 mm and a wall thickness of 0.3 mm is treated by plasma in an air atmosphere at a power of 500 W for 100 s; then a carbon fiber mesh layer is woven outside the inner liner tube by a weaving machine. The carbon fiber with a tensile strength of about 4000 MPa, a wire diameter of about 6 μm, about 300 wires per strand, and a total of 64 strands is selected and woven in a 1-over-1 weaving method with a pitch of 8.0 mm; a PU outer covering layer and a PO expansion tube are sleeved outside the tube and heat-treated at 240 °C to shrink the PO expansion tube and melt the PU to cover the inner liner tube to fuse the three layers of materials together.

[0026] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A medical carbon fiber composite tube, which is a three-layer composite tube structure and consists of an inner lining layer (1), a reinforcing layer (2), and an outer covering layer (3) from inside to outside. It is characterized in that, The outer covering layer (3) includes an expansion tube, which makes the inner lining layer (1), the reinforcing layer (2) and the outer covering layer (3) fit together and fixes the reinforcing layer (2). The reinforcing layer (2) is a carbon fiber braided mesh layer or a wire winding layer.

2. The medical carbon fiber composite tube according to claim 1, wherein, The surface of the inner lining layer (1) is a rough surface. The inner lining layer (1) is an inner lining extrusion tube made of one or two of polytetrafluoroethylene, perfluoroethylene-propylene copolymer, and soluble polytetrafluoroethylene by co-extrusion or laminated extrusion. The thickness of the inner lining layer (1) is 0.02 - 1.0 mm.

3. A medical carbon fiber composite tube according to claim 1, characterized in that, The thickness of the reinforcing layer (2) is 0.01 - 0.50 mm. The tensile strength of the carbon fiber in the reinforcing layer (2) is not less than 3500 MPa, and the wire diameter is less than 10 μm.

4. A medical carbon fiber composite tube according to claim 1, wherein, The outer covering layer (3) further includes an outer covering extrusion tube, which is filled between the inner lining layer (1), the reinforcing layer (2) and the expansion tube.

5. A medical carbon fiber composite tube according to claim 4, wherein, The thickness of the outer covering layer (3) is 0.02 - 1.0 mm. The materials of the outer covering extrusion tube and the expansion tube are polyamide, polyether block polyamide, polyurethane, polytetrafluoroethylene, perfluoroethylene-propylene copolymer or polyolefin.

6. A medical carbon fiber composite tube and its preparation method, characterized in that, It includes the following steps: Step 1): The outer surface of the inner lining extrusion tube is first treated by plasma etching to increase the surface roughness and reduce the surface energy. Step 2): Carbon fiber is directly woven or wound on the surface of the treated inner lining extrusion tube. Step 3): If the outer covering layer (3) only includes the expansion tube, execute Steps 4 to 5; if the outer covering layer (3) includes the expansion tube and the outer covering extrusion tube, execute Steps 6 to 7. Step 4): Put the expansion tube on the outer surface of the inner lining extrusion tube with carbon fiber. Step 5): Heat to make the expansion tube shrink, and fit the inner lining layer (1), the reinforcing layer (2) and the expansion tube together. Step 6): Put the outer covering extrusion tube and the expansion tube on the outer surface of the inner lining extrusion tube with carbon fiber from the inside to the outside in sequence. Step 7): Melt the outer covering extrusion tube to fuse the inner lining layer (1), the reinforcing layer (2) and the expansion tube together.

7. The preparation method of the medical carbon fiber composite tube according to claim 6, characterized in that: In Step 1), the plasma etching treatment uses air, the treatment time is 100 - 1000 s, and the power is 300 - 600 W.

8. The preparation method of the medical carbon fiber composite tube according to claim 6, characterized in that: In Step 2), each strand of the carbon fiber bundle for carbon fiber weaving or winding is 20 - 500 wires, and the pitch is 0.5 - 5 mm.

9. The preparation method of the medical carbon fiber composite tube according to claim 6, characterized in that: In Step 5 and Step 7), the heating temperature is 200 - 360 °C.

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