Preparation method, product and application of double-layer fluororesin conduit

Abstract

The invention relates to the technical field of double-layer fluororesin catheters, in particular to a preparation method of a double-layer fluororesin catheter, a product and application. A preparation method of a double-layer fluororesin catheter comprises the following steps that fluororesin is used for preparing an inner tube and an outer tube, and the inner tube is sleeved with the outer tube in a penetrating mode to obtain a sleeve; and plugging one end of the sleeve, placing the sleeve in a processing device, and sequentially preheating, expanding and cooling to obtain the double-layer fluororesin conduit. The double-layer fluororesin catheter provided by the invention has a good bonding effect, the inner layer is excellent in lubricity, and the outer layer needs to be soft and has no toxic or side effect.

Description

Technical Field

[0001] The invention relates to the technical field of double-layer fluororesin catheters, and in particular to a preparation method, a product and an application of a double-layer fluororesin catheter. Background Art

[0002] Endoscopes used in medical devices usually integrate multiple functions. Endoscopes include LED light tubes, water vapor tubes, electronic cameras, etc. However, endoscopes cannot be directly inserted into the human body for use. A clamp channel tube is required as the channel of the endoscope to be inserted into the human body. The inner layer of the clamp channel tube needs to be in contact with the instrument or other multiple pipes, so the friction resistance of the inner surface needs to be reduced. The natural channels in the human body are tortuous, small in space, and have delicate mucous membranes. The outer layer of the clamp channel tube needs to be soft and non-toxic. If the clamp channel tube adopts a single-layer structure, it is difficult to pass through the natural channels in the human body smoothly, and it is easy to bend, which may lead to surgical failure or cause pain to the patient. Therefore, the layer structure of the clamp channel tube needs to be improved, and the friction resistance of its inner surface needs to be reduced. The outer layer needs to be soft and non-toxic to better meet the use requirements of medical devices in the complex environment of the human body.

[0003] A Chinese patent with patent publication number CN111449701A discloses a clamp channel tube, which includes a head portion, which is a multi-layer composite structure of at least 3 layers and is arranged inside the end of the endoscope head; a tail portion, which is a single-layer structure and is used to connect the endoscope handle; a transition section, which is arranged between the head portion and the tail portion, and the transition section is a multi-layer composite structure to solve the risks of easy breakage, easy flattening and damage; but there is no disclosure of a technical solution that requires the inner layer to have excellent lubricity and the outer layer to be soft and non-toxic.

[0004] Therefore, the main technical problem that needs to be solved at present is to provide a double-layer fluororesin catheter with a multi-layer structure, an inner layer with excellent lubricity, an outer layer that is soft, non-toxic, and has good bending properties. Summary of the invention

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a method for preparing a double-layer fluororesin catheter, comprising the following steps:

[0006] An inner tube and an outer tube are prepared by using fluororesin, and the inner tube is inserted into the outer tube to obtain a casing;

[0007] After sealing one end of the casing, it is placed in a processing device and preheated, expanded, and cooled in sequence to obtain a double-layer fluororesin catheter.

[0008] In one embodiment, the inner tube is placed in a plasma machine for surface treatment and then used; the process of placing the inner tube in a plasma machine for surface treatment includes first evacuating the inner tube plasma treatment environment and then filling it with nitrogen atmosphere, with a nitrogen gas flow rate of 5 cm 3 / min, the energy is 400w, and the processing time is 3min after the nitrogen gas flow is stable. After the processing is completed, the inner tube is taken out.

[0009] In one embodiment, one end of the sleeve may be sealed by tying a knot or clamping it with a tool to achieve an airtight effect.

[0010] In one embodiment, the preparation process of the inner tube comprises:

[0011] The inner tube is obtained by aging, preforming, extruding, sintering and cooling the PTFE powder.

[0012] In one embodiment, the preparation process of the inner tube comprises:

[0013] S1. After mixing PTFE powder and auxiliary oil, the mixture is aged at 30°C, and after the mixture is aged, the mixture is preformed at a pressure of 2 to 3 MPa to remove air and form a cylindrical blank;

[0014] S2. The blank is placed in a mold in an extrusion device and extruded. The extruded tubular product enters a sintering furnace after volatilization. The sintering temperature is 400-500°C. The inner tube is obtained after sintering for 1.5-3 minutes and cooling.

[0015] The PTFE powder for the inner tube is purchased from Japan Daikin Fluorochemical PTFE F201.

[0016] In one embodiment, the preparation process of the outer tube comprises:

[0017] The PTFE powder is subjected to ripening, preforming, stretching and extrusion, volatilization, rapid sintering and cooling to obtain an outer tube; the outer tube is an expanded PTFE outer tube.

[0018] In one embodiment, the preparation process of the outer tube comprises:

[0019] S1. After mixing PTFE powder and auxiliary oil, the mixture is aged at 30°C, and after the mixture is aged, the mixture is preformed at a pressure of 2 to 3 MPa to remove air and form a cylindrical blank;

[0020] S2. The blank is placed in a mold in an extrusion device and extruded. The extruded tubular product is stretched by a traction machine while volatilizing. The stretching temperature is 200 to 250° C., and the stretching speed is 1.5 to 3 times the extrusion line speed. The two ends of the stretched tubular product are clamped and rapidly sintered at 350 to 400° C. for 0.5 to 1 min, and then cooled and shaped to obtain an outer tube.

[0021] In one embodiment, the extrusion line speed is 1-3 m / min.

[0022] In one embodiment, the extrusion line speed is 2 m / min.

[0023] The PTFE powder for the outer tube is purchased from Japan Daikin Fluorochemical PTFE F104.

[0024] In one embodiment, the inner diameter of the inner tube is 3.5-3.8 mm, and the outer diameter is 3.85-4.1 mm;

[0025] In one embodiment, the inner diameter of the outer tube is 4.2-4.6 mm, and the outer diameter is 5.0-6.2 mm.

[0026] In one embodiment, the inner diameter of the inner tube is 3.7 mm and the outer diameter is 4.0 mm.

[0027] In one embodiment, the inner diameter of the outer tube is 4.3 mm and the outer diameter is 5.8 mm.

[0028] In one embodiment, the preheating temperature is greater than or equal to 240° C.; the preheating includes primary preheating and secondary preheating.

[0029] In one embodiment, the primary preheating temperature is 240-260°C.

[0030] In one embodiment, the primary preheating temperature includes but is not limited to 240°C, 241°C, 242°C, 243°C, 244°C, 245°C, 246°C, 247°C, 248°C, 249°C, 250°C, 251°C, 252°C, 253°C, 254°C, 255°C, 256°C, 257°C, 258°C, 259°C, and 260°C.

[0031] In one embodiment, the primary preheating temperature is 250°C.

[0032] In one embodiment, the secondary preheating temperature is 290-310°C.

[0033] In one embodiment, the secondary preheating temperature includes but is not limited to 290°C, 291°C, 292°C, 293°C, 294°C, 295°C, 296°C, 297°C, 298°C, 299°C, 300°C, 301°C, 302°C, 303°C, 304°C, 305°C, 306°C, 307°C, 308°C, 309°C, and 310°C.

[0034] In one embodiment, the secondary preheating temperature is 300°C.

[0035] In one embodiment, the expansion temperature is 335-345°C.

[0036] In one embodiment, the expansion temperature includes but is not limited to 335°C, 336°C, 337°C, 338°C, 339°C, 340°C, 241°C, 242°C, 243°C, 244°C, and 245°C.

[0037] In one embodiment, the expansion temperature is 340°C.

[0038] In one embodiment, the cooling temperature is 10-20°C.

[0039] In one embodiment, the cooling temperature includes but is not limited to 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C.

[0040] In one embodiment, the cooling temperature is 15°C.

[0041] In one embodiment, the processing is set up with a pulling speed of 0.15-0.25 m / min.

[0042] In one embodiment, the pulling speed of the processing setting includes but is not limited to 0.15m / min, 0.16m / min, 0.17m / min, 0.18m / min, 0.19m / min, 0.20m / min, 0.21m / min, 0.22m / min, 0.23m / min, 0.24m / min, and 0.25m / min.

[0043] In one embodiment, the processing is set up with a pulling speed of 0.20 m / min.

[0044] In one embodiment, after one end of the sleeve is sealed, the other end of the sleeve is connected to an inflation device, the other end of the sleeve cannot leak, and air is inflated into the gap between the inner tube and the outer tube, and the inflation pressure is 0.018-0.03MPa.

[0045] In one embodiment, the inflation pressure includes but is not limited to 0.018 MPa, 0.019 MPa, 0.02 MPa, 0.021 MPa, 0.022 MPa, 0.023 MPa, 0.024 MPa, 0.025 MPa, 0.026 MPa, 0.027 MPa, 0.028 MPa, 0.029 MPa, and 0.03 MPa.

[0046] In one embodiment, the inflation pressure is 0.02 MPa.

[0047] In order to promote the bonding effect between the inner tube and the outer tube, the inner layer of the double-layer fluororesin catheter has excellent lubricity, and the outer layer needs to be soft, non-toxic and non-bending; the inventor found in the experiment that the inner tube can be placed in a plasma machine for surface treatment; the inner tube is placed in a plasma machine for surface treatment, and the inner tube plasma treatment environment is first vacuumed, then filled with nitrogen atmosphere, and the nitrogen gas flow rate is 5cm 3 / min, the energy is 400w, and the processing time is 3min after the nitrogen gas flow is stable. After the processing is completed, the inner tube is taken out and then inserted into the outer tube to obtain the sleeve; one end of the sleeve is blocked and placed in the processing setting for preheating, expansion and cooling in sequence to obtain a double-layer fluororesin catheter; the preheating temperature is greater than or equal to 240℃; the preheating includes primary preheating and secondary preheating; the primary preheating temperature is 240-260℃; the secondary preheating temperature is 290-310℃; the expansion temperature is 335-345℃; the traction speed of the processing setting is 0.15-0.25m / min; the inflation pressure is 0.018-0.03MPa, and the cooling temperature is 10-20℃; by adopting the above-mentioned preheating, expansion and cooling methods Under the action of the expansion of the internal air pressure and the slight melting of the high-temperature zone, the inner tube and the outer tube can be bonded together, and the obtained double-layer fluororesin catheter has a good bonding effect. However, the inventor found that when the secondary preheating is low and the expansion temperature is low, the inner tube and the outer tube of the obtained double-layer fluororesin catheter will appear unbonded and layered; when the inflation pressure used is small, the bonding effect of the inner tube and the outer tube of the double-layer fluororesin catheter is not strong enough, and the peeling force is relatively low; when the traction speed used is too fast, there will be a problem of insufficient welding time, which will cause the inner tube and the outer tube of the double-layer fluororesin catheter to not be firmly bonded; when the expansion temperature is too high and the traction speed is too fast, the inner tube and the outer tube will appear in an over-sintered state, the tube will be hard, the bending performance is poor, the tube will appear transparent, and it will no longer have the expanded properties.

[0048] The second aspect of the present invention provides a double-layer fluororesin catheter, which is prepared by the preparation method of the double-layer fluororesin catheter.

[0049] The double-layer fluororesin conduit comprises an inner tube and an outer tube, wherein the inner tube is a PTFE inner tube; and the outer tube is an expanded PTFE outer tube.

[0050] A third aspect of the present invention provides an application of a double-layer fluororesin catheter, wherein the double-layer fluororesin catheter is applied in the technical field of medical devices.

[0051] Beneficial Effects

[0052] 1. The double-layer fluororesin catheter provided in this application has a good bonding effect, the inner layer has excellent lubricity, and the outer layer needs to be soft and non-toxic.

[0053] 2. The preparation method of the double-layer fluororesin catheter provided in the present application can prevent the inner tube and the outer tube of the double-layer fluororesin catheter from being unbonded or delaminated.

[0054] 3. The preparation method of the double-layer fluororesin catheter provided in the present application can avoid the problem that the bonding effect between the inner tube and the outer tube of the double-layer fluororesin catheter is not strong enough and the tear strength is relatively low.

[0055] 4. The method for preparing a double-layer fluororesin catheter provided in the present application can avoid the problem of the inner tube and the outer tube of the double-layer fluororesin catheter not being firmly bonded.

[0056] 5. The preparation method of the double-layer fluororesin catheter provided in the present application can improve the resilience of the double-layer fluororesin catheter and has good bending performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 Schematic diagram of the preparation process of the double-layer fluororesin catheter provided in Example 1.

[0058] Figure 2 This is a schematic diagram of the structure of the double-layer fluororesin catheter provided in Example 1.

[0059] Figure 3 The double-layer fluororesin catheter provided for Comparative Example 1 appears in an unbonded state and a delaminated state.

[0060] Figure 4 The double-layer fluororesin catheter provided for Comparative Example 1 appears in an unbonded state and a delaminated state.

[0061] Figure 5 This is a diagram showing the variation of the peeling force during the peeling force test of the double-layer fluororesin catheter provided in Example 1.

[0062] Figure 6 This is the minimum bending diameter test method.

[0063] Figure 7 This is a method for testing resilience.

[0064] Figure 8 The outer tube body of Example 1 is in a white state.

[0065] Fig. 9 The outer tube body of Comparative Example 4 is in a transparent state.

[0066] Figure 1 Middle: 01. Pipe pay-off drum (including air pressure); 02. Casing; 03. Primary preheating zone; 04. Secondary preheating zone; 05. Expansion zone; 06. Cooling zone; 07. Traction wheel for processing; 08. Finished pipe collection zone.

[0067] Figure 2 Middle: 101, outer tube; 102, inner tube. DETAILED DESCRIPTION

[0068] Example 1

[0069] A first aspect of the present embodiment provides a method for preparing a double-layer fluororesin catheter, comprising the following steps:

[0070] An inner tube and an outer tube are prepared by using fluororesin, and the inner tube is inserted into the outer tube to obtain a casing;

[0071] After sealing one end of the casing, it is placed in a processing device and preheated, expanded, and cooled in sequence to obtain a double-layer fluororesin catheter.

[0072] Figure 1 A schematic diagram of the preparation process of the double-layer fluororesin catheter provided in this embodiment.

[0073] The inner tube is placed in a plasma machine for surface treatment and then used; the process of placing the inner tube in a plasma machine for surface treatment includes first evacuating the inner tube plasma treatment environment and then filling it with nitrogen atmosphere, with a nitrogen gas flow rate of 5cm 3 / min, the plasma energy is 400w, the processing time is 3min after the nitrogen gas flow is stable, and the inner tube is taken out after the processing is completed.

[0074] After sealing one end of the casing, the effect of preventing air leakage is achieved.

[0075] The preparation process of the inner tube comprises:

[0076] S1. By mass percentage, 75wt% PTFE powder and 25wt% additive oil were mixed and aged at 30 ° C. After aging, the preformed material was removed from the air at a pressure of 2MPa to form a cylindrical blank;

[0077] S2. The blank is placed in a mold in an extrusion device and extruded. The extruded tubular material enters a sintering furnace after volatilization. The sintering temperature is 420°C and the sintering time is 2 minutes. The inner tube is obtained after cooling. The cooling temperature is 25°C. The inner tube is a PTFE tube.

[0078] The PTFE powder for the inner tube is purchased from Japan Daikin Fluorochemical F201.

[0079] The manufacturer's model of the auxiliary oil for the inner tube is ExxonMobil G type.

[0080] The inner diameter of the inner tube is 3.7 mm, and the outer diameter is 4.0 mm.

[0081] The preparation process of the outer tube comprises:

[0082] S1. By mass percentage, 75wt% PTFE powder and 25wt% additive oil were mixed and aged at 30 ° C. After aging, the preformed material was removed from the air at a pressure of 2MPa to form a cylindrical blank;

[0083] S2. The blank is placed in a mold in an extrusion device and extruded. The extruded tubular product is stretched by a traction machine while volatilizing. The stretching temperature is 200°C and the stretching speed is twice the extrusion line speed. The extrusion line speed is 2m / min. The two ends of the stretched tubular product are clamped and rapidly sintered at 350°C for 1 minute, and then cooled and shaped to obtain an outer tube. The cooling temperature is 25°C. The outer tube is an expanded PTFE outer tube.

[0084] The PTFE powder for the outer tube is purchased from Japan's Daikin Fluorochemical PTFE F104.

[0085] The auxiliary oil for the outer tube is purchased from ExxonMobil G type.

[0086] The inner diameter of the outer tube is 4.3 mm, and the outer diameter is 5.8 mm.

[0087] The preheating includes primary preheating and secondary preheating.

[0088] The primary preheating temperature is 250°C.

[0089] The secondary preheating temperature is 300°C.

[0090] The expansion temperature is 340°C.

[0091] The cooling temperature is 15°C.

[0092] The pulling speed of the processing setting is 0.20m / min.

[0093] After one end of the sleeve is blocked, the other end of the sleeve is connected to the inflation device. The other end of the sleeve cannot leak air, and air is inflated into the gap between the inner tube and the outer tube. The inflation pressure is 0.02MPa.

[0094] A second aspect of this embodiment provides a double-layer fluororesin catheter, which is prepared by the preparation method of the double-layer fluororesin catheter.

[0095] The double-layer fluororesin conduit comprises an inner tube and an outer tube, wherein the inner tube is a PTFE tube; and the outer tube is an expanded PTFE outer tube.

[0096] Figure 2 A schematic diagram of the structure of a double-layer fluororesin catheter is provided.

[0097] A third aspect of the present embodiment provides an application of a double-layer fluororesin catheter, which is applied in the technical field of medical devices.

[0098] Comparative Example 1

[0099] This comparative example provides a method for preparing a double-layer fluororesin catheter. The specific implementation method is the same as that of Example 1, except that the secondary preheating temperature is 280°C and the expansion temperature is 330°C.

[0100] This comparative example provides a double-layer fluororesin catheter, which is prepared by the preparation method of the double-layer fluororesin catheter.

[0101] The double-layer fluororesin catheter obtained in this comparative example has an inner layer tube and an outer layer tube that are not bonded and are in a delaminated state. Figure 3 and Figure 4 .

[0102] Comparative Example 2

[0103] This comparative example provides a method for preparing a double-layer fluororesin catheter. The specific implementation method is the same as Example 1, except that after one end of the sleeve is sealed, the other end of the sleeve is connected to an inflation device, and the other end of the sleeve cannot leak. Air is inflated into the gap between the inner tube and the outer tube, and the inflation pressure is 0.01 MPa.

[0104] This comparative example provides a double-layer fluororesin catheter, which is prepared by the preparation method of the double-layer fluororesin catheter.

[0105] Comparative Example 3

[0106] This comparative example provides a method for preparing a double-layer fluororesin catheter, and the specific implementation method is the same as that of Example 1, except that the pulling speed of the processing setting is 0.40 m / min.

[0107] This comparative example provides a double-layer fluororesin catheter, which is prepared by the preparation method of the double-layer fluororesin catheter.

[0108] Comparative Example 4

[0109] This comparative example provides a method for preparing a double-layer fluororesin catheter. The specific implementation method is the same as that of Example 1, except that the expansion temperature is 380° C. and the pulling speed of the processing setting is 0.40 m / min.

[0110] This comparative example provides a double-layer fluororesin catheter, which is prepared by the preparation method of the double-layer fluororesin catheter.

[0111] Performance Testing

[0112] 1 Peeling performance test:

[0113] The double-layer fluororesin conduits provided in Example 1 and Comparative Examples 1-4 were tested for peeling force between the inner tube and the outer tube according to GB / T 8808-1988 Peeling Test Method for Soft Composite Plastic Materials. The test speed was 50 mm / min. The test results are shown in Table 1.

[0114] The peeling force variation state of the double-layer fluororesin catheter provided in Example 1 during the peeling force test is shown in FIG. Figure 5 .

[0115] 2. Minimum bending diameter test:

[0116] A certain length of the double-layer fluororesin tube provided in Example 1 and Comparative Examples 1-4 was taken and placed in the tooling. One end of the tooling was fixed and the other end was translated inward until a crease appeared on the top of the tube. The movement was stopped and the minimum bending radius of the double-layer fluororesin tube was recorded. The test method is shown in Figure 6 , the test results are shown in Table 1.

[0117] 3. Resilience test:

[0118] Take a certain length of the double-layer fluororesin tube provided in Example 1 and Comparative Examples 1-4 respectively and put them in the tooling, bend the double-layer fluororesin tube to 180° and then release the active end to observe the instantaneous rebound angle of the double-layer fluororesin tube. The test method is shown in Figure 7 ; The test results are shown in Table 1.

[0119] 4. Outer tube color test:

[0120] The colors of the outer tube bodies of the double-layer fluororesin catheters provided in Example 1 and Comparative Examples 1-4 were recorded. The results are shown in Table 1.

[0121] The outer tube body of the double-layer fluororesin catheter provided in Example 1 is white in color. Figure 8 .

[0122] The outer tube body of the double-layer fluororesin catheter provided in Comparative Example 4 is transparent. Fig. 9 .

[0123] Table 1

[0124]

[0125] In Table 1, “ / ” means that it cannot be measured.

[0126] The double-layer fluororesin catheter provided in Comparative Example 1 had an inner tube and an outer tube that were not bonded and were in a delaminated state, and the tearing force could not be measured.

[0127] In the double-layer fluororesin catheter provided in Comparative Example 4, the inner tube and the outer tube were firmly bonded, and the contact interface between the inner tube and the outer tube was completely melted, so the tearing force could not be measured.

[0128] When the secondary preheating and expansion temperature used in Comparative Example 1 are low, the inner and outer tubes of the obtained double-layer fluororesin catheter will be unbonded and delaminated; when the inflation pressure used in Comparative Example 2 is small, the bonding effect of the inner and outer tubes of the double-layer fluororesin catheter is not strong enough, and the tear strength is relatively low. When the pulling speed used in Comparative Example 3 is too fast, the problem of insufficient welding time will occur, resulting in the inner and outer tubes of the double-layer fluororesin catheter not being firmly bonded. When the expansion temperature used in Comparative Example 4 is too high and the pulling speed is too fast, the inner and outer tubes will be over-sintered, the tube will be hard, the bending performance will be poor, the tube will be transparent, and it will no longer have the expanded properties.

Claims

1. A method for preparing a double-layer fluororesin catheter, characterized in that: The following steps are involved: An inner tube and an outer tube are prepared by using fluororesin, and the inner tube is inserted into the outer tube to obtain a casing; After sealing one end of the casing, it is placed in a processing device and preheated, expanded, and cooled in sequence to obtain a double-layer fluororesin catheter.

2. The method for preparing a double-layer fluororesin catheter according to claim 1, characterized in that: The preheating temperature is greater than or equal to 240° C.; the preheating includes primary preheating and secondary preheating.

3. The method for preparing a double-layer fluororesin catheter according to claim 2, characterized in that: The primary preheating temperature is 240-260°C.

4. The method for preparing a double-layer fluororesin catheter according to claim 2, characterized in that: The secondary preheating temperature is 290-310°C.

5. The method for preparing a double-layer fluororesin catheter according to any one of claims 1 to 4, characterized in that: The expansion temperature is 335-345°C.

6. The method for preparing a double-layer fluororesin catheter according to claim 1, characterized in that: The cooling temperature is 10-20°C.

7. The method for preparing a double-layer fluororesin catheter according to claim 1, characterized in that: The pulling speed of the processing setting is 0.15-0.25m / min.

8. The method for preparing a double-layer fluororesin catheter according to claim 1, characterized in that: After one end of the sleeve is sealed, the other end of the sleeve is connected to the inflation device to inflate air into the gap between the inner tube and the outer tube, and the inflation pressure is 0.018-0.03MPa.

9. A double-layer fluororesin catheter, characterized in that: The double-layer fluororesin catheter is prepared by the preparation method of any one of claims 1 to 8.

10. An application of a double-layer fluororesin catheter, characterized in that: The double-layer fluororesin catheter is used in the technical field of medical devices.

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