Expanded polytetrafluoroethylene product preforming equipment
By using liquid nitrogen to pre-cool and cool the engraving table and plates in the engraving equipment of the expanded polytetrafluoroethylene implant, the problem of fiber burrs during the engraving process is solved, and the surface smoothness of the implant is achieved.
Patent Information
- Application Number
- CN202421744402.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-22
- Publication Date
- 2025-05-09
- Estimated Expiration
- 2034-07-22
AI Technical Summary
When engraving the expanded polytetrafluoroethylene implant, fiber burrs are easily generated due to the microporous fiber structure in the plate, which affects the surface smoothness.
A preforming equipment for expanded polytetrafluoroethylene products was designed, and the engraving table and boards were pre-cooled and cooled by liquid nitrogen. After cooling to -28°C to -32°C, the fiber material became harder and brittle, reducing the generation of burrs.
Through liquid nitrogen cooling technology, the generation of burrs during the engraving process is significantly reduced, and the surface smoothness of the expanded polytetrafluoroethylene implant is ensured.
Smart Images
Figure CN222843674U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of medical device technology, and in particular to an expanded polytetrafluoroethylene product preforming device. Background Art
[0002] Expanded polytetrafluoroethylene (ePTFE) is a material with high biocompatibility and durability. The sheet produced from ePTFE is carved to form an ePTFE implant. The formed ePTFE implant can be used as a prosthesis to replace biological tissue.
[0003] However, due to the microporous fiber structure in the plate, many fiber burrs will be generated on the surface of the expanded polytetrafluoroethylene implant during carving, thereby affecting the surface smoothness of the expanded polytetrafluoroethylene implant. Utility Model Content
[0004] The present application provides an expanded polytetrafluoroethylene product preforming device, which can reduce the generation of burrs during the engraving process and ensure that the produced expanded polytetrafluoroethylene implant has good surface smoothness.
[0005] The expanded polytetrafluoroethylene product preforming equipment provided in this application adopts the following technical solution:
[0006] An expanded polytetrafluoroethylene product preforming device comprises a cabinet, wherein the cabinet is provided with:
[0007] An engraving table, wherein a plurality of cooling holes are provided in the engraving table;
[0008] The knife seat is arranged above the engraving table and has a horizontal and vertical movement stroke;
[0009] A carving knife is set on a knife holder;
[0010] The cooling component includes a liquid storage bottle, a connecting pipe and a control valve. The liquid storage bottle is used to store liquid nitrogen. One end of the connecting pipe is connected to the liquid storage bottle. The other end of the connecting pipe is inserted into the engraving table and is respectively connected to the plurality of cooling holes. The control valve is arranged on the connecting pipe to control the connection and disconnection of the connecting pipe.
[0011] By adopting the above technical solution, before engraving, liquid nitrogen is introduced into the cooling hole to pre-cool the engraving table first, and then the plate is placed on the top surface of the engraving table after pre-cooling. At this time, the liquid nitrogen is still continuously output to further cool the plate. After the plate is cooled to -28°C to -32°C, the engraving operation is then performed. After the plate is cooled, the fiber material becomes hard and brittle, which is convenient for engraving with a carving knife and reduces the generation of burrs.
[0012] Optionally, a pump group is provided in the cabinet, and a plurality of suction holes are provided on the engraving table. The pump group is connected to the suction holes through pipelines. When the pump group is working, negative pressure can be formed at the suction holes to fix the plate.
[0013] By adopting the above technical solution, negative pressure is formed to fix the plate, thereby preventing the plate from shifting when the carving knife is carving the plate.
[0014] Optionally, the cooling hole and the suction hole are staggered.
[0015] By adopting the above technical solution, the cooling hole is prevented from interfering with the suction work.
[0016] Optionally, an anti-skid pad is provided on the top surface of the engraving table, and air holes are opened on the anti-skid pad, and a plurality of the air holes are arranged in a one-to-one correspondence with the plurality of the suction holes.
[0017] By adopting the above technical solution and providing an anti-skid pad, water droplets formed on the engraving table after cooling down are prevented from directly contacting the plate, causing the plate to slip during the engraving process.
[0018] Optionally, a spray head is provided on the knife holder, and the spray head is connected to the liquid storage bottle.
[0019] By adopting the above technical solution, the carving knife will heat up rapidly during the carving process due to its high rotation speed, and the nozzle can move synchronously with the carving knife. Liquid nitrogen is output from the nozzle to further cool the carving knife and the plate on the carving table, thereby protecting the carving knife and maintaining the low temperature of the plate.
[0020] Optionally, a cleaning device is further provided in the cabinet, and the cleaning device includes:
[0021] A water absorbing block is arranged on the carving table and fits with the top surface of the carving table;
[0022] The driving rod is plugged into the water absorbing block and slidably connected to the engraving table to drive the water absorbing block to move.
[0023] By adopting the above technical solution, before the anti-skid pad is attached to the engraving table, the driving rod is first slid to drive the water absorption block to clean the condensed water drops on the engraving table to ensure the dryness of the engraving table.
[0024] In summary, the present application includes at least one of the following beneficial technical effects:
[0025] 1. Before engraving, introduce liquid nitrogen into the cooling hole to pre-cool the engraving table first. After pre-cooling, place the plate on the top of the engraving table. At this time, the liquid nitrogen is still continuously output to further cool the plate. After the plate is cooled to -30°C, the engraving operation can be carried out. After the plate is cooled, the fiber material becomes hard and brittle, which is convenient for engraving with a carving knife and reduces the generation of burrs.
[0026] 2. By forming negative pressure, the plate is fixed to prevent the possibility of the plate shifting when the engraving knife is engraving on the plate. By setting an anti-slip pad, it is further prevented that the water droplets formed on the engraving table after cooling down directly contact the plate, causing the plate to slip during the engraving process.
[0027] 3. During the engraving process, the carving knife will heat up rapidly due to its high rotation speed, and the nozzle can move synchronously with the carving knife. Liquid nitrogen is output from the nozzle to further cool the carving knife and the plate on the engraving table, protect the carving knife, and maintain the low temperature of the plate. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a three-dimensional structural schematic diagram of the preforming device in this application;
[0029] Figure 2 It is a partial structural schematic diagram of the preforming equipment in this application;
[0030] Figure 3 It is a schematic cross-sectional view of the engraving table in the present application.
[0031] In the figure, 1. cabinet; 2. engraving table; 21. cooling hole; 22. suction hole; 3. knife holder; 4. carving knife; 5. cooling part; 51. liquid storage bottle; 52. connecting pipe; 53. control valve; 6. pump group; 7. anti-slip mat; 71. air hole; 8. movable table; 9. cleaning part; 91. water absorption block; 92. driving rod; 10. nozzle. DETAILED DESCRIPTION
[0032] The following is combined with Figure 1 -Attached Figure 3 , further details of this application are given.
[0033] A preforming equipment for expanded polytetrafluoroethylene products, referring to Figure 1 and Figure 2 , including a cabinet 1, in which an engraving table 2, a knife holder 3 and a carving knife 4 are arranged. The knife holder 3 is arranged above the engraving table 2, and the carving knife 4 is arranged on the knife holder 3 and is arranged toward the engraving table 2. The knife holder 3 has a horizontal and vertical movement stroke. By moving the knife holder 3, the carving knife 4 is driven to perform a carving operation on the plate on the engraving table 2, so that the carving knife 4 carves a required shape on the plate.
[0034] Furthermore, a movable table 8 is provided on the bottom side of the engraving table 2, and the movable table 8 is slidably connected in the cabinet 1 to drive the engraving table 2 to move. When the carving knife 4 engraves the plate, the movable table 8 slides along its own length direction to adjust the position of the engraving table 2 and further cooperate with the direction of the carving knife 4.
[0035] Combination Figure 3 A cooling component 5 is also provided in the cabinet 1 for cooling the engraving table 2 and the plate mounted on the engraving table 2. Specifically, the cooling component 5 includes a liquid storage bottle 51, a connecting pipe 52 and a control valve 53. A plurality of cooling holes 21 are provided in the engraving table 2. The liquid storage bottle 51 is used to store liquid nitrogen. In this embodiment, the liquid storage bottle 51 adopts a self-enhanced liquid nitrogen tank. One end of the connecting pipe 52 is connected to the liquid storage bottle 51, and the other end is inserted into the engraving table 2 and respectively connected to the plurality of cooling holes 21. The control valve 53 is provided on the connecting pipe 52 for controlling the on-off of the connecting pipe 52, thereby controlling the amount of liquid nitrogen introduced.
[0036] Before engraving, liquid nitrogen is introduced into the cooling hole 21 to pre-cool the engraving table 2. After pre-cooling, the plate is placed on the top surface of the engraving table 2. At this time, the liquid nitrogen is still continuously output to further cool the plate. Specifically, in this embodiment, the plate is cooled to -30±2°C (i.e., between -28°C and -32°C) before engraving. After the plate is cooled, the fiber material becomes hard and brittle, which facilitates engraving by the carving knife 4 and reduces the generation of burrs.
[0037] In addition, a nozzle 10 is also provided on the tool holder 3, and the nozzle 10 is connected to the liquid storage bottle 51 through a pipeline (not shown in the figure), and a control valve 53 is also provided on the pipeline to control the on-off of the pipeline. Furthermore, a plurality of engraving knives 4 are provided. In the present embodiment, the number of engraving knives 4 is two, and the two engraving knives 4 are arranged opposite to each other on the bottom side of the tool holder 3, and the nozzle 10 is arranged between the two engraving knives 4, and two nozzles are provided on the nozzle 10, and the two nozzles are arranged one by one with the two engraving knives 4, and the output end of the nozzle faces the engraving knives 4.
[0038] When the control valve 53 on the pipeline is opened, liquid nitrogen is sprayed out from the nozzle on the nozzle 10, first acting on the carving knife 4 to cool down the carving knife 4, preventing the carving knife 4 from rapidly heating up during the engraving process, thereby protecting the carving knife 4. After the liquid nitrogen exchanges heat with the carving knife 4, it falls onto the plate, further cooling the plate to maintain the plate at a low temperature.
[0039] It should be noted that, in the present embodiment, the pipe between the nozzle 10 and the liquid storage bottle 51 and the connecting pipe 52 are both made of metal hoses, and an insulation pipe is further sheathed outside the metal hose. The insulation pipe is made of plastic material to reduce the amount of heat exchange between the liquid nitrogen and the outside air before heat exchange occurs between the liquid nitrogen and the engraving knife 4 and the plate, thereby maintaining the low temperature state of the liquid nitrogen.
[0040] In addition, in this embodiment, a control panel is provided on the cabinet door of the cabinet 1, and a controller is provided on the control panel. The controller is electrically connected to the movable table 8, the tool holder 3, the engraving knife 4 and the control valve 53. By inputting a program into the controller, the positions of the engraving table 2 and the tool holder 3, the operating state (rotation speed and cutting feed rate) of the engraving knife 4 and the liquid nitrogen flow rate can be adjusted.
[0041] It should be noted that the control panel and the controller are both mature existing technologies and are not specifically shown in the figures.
[0042] Furthermore, since the engraving table 2 is precooled first, after the precooling is completed, water droplets will condense on the engraving table 2. Figure 1 and Figure 2 In this embodiment, a cleaning member 9 is provided in the cabinet 1, and the cleaning member 9 includes a water absorbing block 91 and a driving rod 92, wherein the water absorbing block 91 is horizontally arranged on the engraving table 2 and fits with the top surface of the engraving table 2. In this embodiment, the water absorbing block 91 is made of a sponge block, and in other embodiments, it can also be made of cloth.
[0043] The driving rod 92 is plugged into the water absorbing block 91 and slidably connected to the engraving table 2. The driving rod 92 is driven by a motor. When the driving rod 92 slides, it drives the water absorbing block 91 to clean the condensed water droplets on the top surface of the engraving table 2, thereby ensuring the dryness of the engraving table 2.
[0044] Furthermore, in this embodiment, a non-slip pad 7 is provided on the top surface of the engraving table 2. When the water drops on the engraving table 2 are cleaned, the protective pad is bonded to the engraving table 2 to prevent the plate from slipping during the engraving process.
[0045] Further, refer to Figure 1 and Figure 2 In order to better fix the plate, a plurality of suction holes 22 are provided on the engraving table 2, and a pump group 6 is provided in the cabinet. These suction holes 22 are connected to the pump group 6. When the pump group 6 is working, negative pressure can be formed at the suction holes 22, thereby fixing the plate placed on the engraving table 2. Correspondingly, in this embodiment, a plurality of air holes 71 are provided on the anti-slip mat 7. The plurality of air holes 71 are arranged in a one-to-one correspondence with the plurality of suction holes 22. When the anti-slip mat 7 is laid on the engraving table 2, the air holes 71 are connected to the suction holes 22.
[0046] In addition, an embodiment of the present application also provides an engraving process, which is implemented based on the above-mentioned preforming device and includes the following steps:
[0047] S1. Cut the sheet into pieces according to the outer contour size of the product to be formed, put the cut sheets into cloth bags for sealing, and then put them into an ultra-low temperature refrigerator below -40°C. The freezing time in the ultra-low temperature refrigerator is not less than 12 hours;
[0048] S2, introducing liquid nitrogen into the cooling hole 21 to pre-cool the engraving table 2;
[0049] S3, after the precooling is completed, the water drops formed on the engraving table 2 are cleaned, and a layer of anti-skid pad 7 is attached to the top surface of the engraving table 2, and then the cut plate is placed on the engraving table 2;
[0050] S4. Continue to introduce liquid nitrogen until the temperature of the plate drops to between -28°C and -32°C;
[0051] S5, start the carving knife 4, and move the knife holder 3, so that the carving knife 4 carves the plate. During the carving process, liquid nitrogen is continuously blown toward the position where the carving knife 4 is located to cool the carving knife 4.
[0052] During the engraving process, the rotation speed of the engraving knife 4 is 20000-30000 rpm, and the cutting feed rate is 2500-3500 mmpm.
[0053] It should be noted that:
[0054] In S1, the bag is made of polyester cloth.
[0055] In S3, the water droplets can be cleaned by the water absorption block 91, which is driven by the driving rod 92 to move on the engraving table 2 to absorb and remove the water droplets. When the plate is placed on the engraving table 2, the pump group 6 works to form a negative pressure at the suction hole 22 to fix the plate.
[0056] In S4, the temperature of the plate is monitored in real time by a temperature sensor.
[0057] The principles of the embodiments of the present application are as follows:
[0058] Before engraving the plate, the plate is cut into multiple pieces to reduce the time the whole plate is exposed to the air, and the cut plate is placed in an ultra-low temperature refrigerator so that the plate has a lower temperature when placed on the engraving table 2. The plate and the engraving table 2 are then cooled by liquid nitrogen to maintain the low temperature of the plate. The plate becomes hard and brittle, which is convenient for engraving by the carving knife 4 and reduces the generation of burrs.
[0059] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.
Claims
1. An expanded polytetrafluoroethylene product preforming device, characterized in that: The invention comprises a cabinet (1), wherein the cabinet (1) is provided with: An engraving table (2), wherein a plurality of cooling holes (21) are provided in the engraving table (2); A knife seat (3) is arranged above the engraving table (2) and has a horizontal and vertical movement stroke; A carving knife (4) is arranged on the knife seat (3); The cooling element (5) comprises a liquid storage bottle (51), a connecting pipe (52) and a control valve (53); the liquid storage bottle (51) is used to store liquid nitrogen; one end of the connecting pipe (52) is connected to the liquid storage bottle (51); the other end of the connecting pipe (52) is inserted into the engraving table (2) and is respectively connected to the plurality of cooling holes (21); the control valve (53) is arranged on the connecting pipe (52) and is used to control the connection and disconnection of the connecting pipe (52).
2. The expanded polytetrafluoroethylene product preforming equipment according to claim 1, characterized in that: A pump group (6) is arranged in the cabinet (1), and a plurality of suction holes (22) are provided on the engraving table (2). The pump group (6) and the suction holes (22) are connected via a pipeline. When the pump group (6) is working, negative pressure can be formed at the suction holes (22) to fix the plate.
3. The expanded polytetrafluoroethylene product preforming equipment according to claim 2, characterized in that: The cooling hole (21) and the suction hole (22) are arranged in a staggered manner.
4. The expanded polytetrafluoroethylene product preforming equipment according to claim 2, characterized in that: An anti-skid pad (7) is arranged on the top surface of the engraving table (2), and an air hole (71) is opened on the anti-skid pad (7), and the air hole (71) is connected to the suction hole (22).
5. The expanded polytetrafluoroethylene product preforming equipment according to claim 1, characterized in that: A movable platform (8) is provided on the bottom side of the engraving table (2); the movable platform (8) is slidably connected in the cabinet (1) and is used to drive the engraving table (2) to move.
6. The expanded polytetrafluoroethylene product preforming equipment according to claim 1, characterized in that: The knife seat (3) is provided with a spray head (10), and the spray head (10) is connected to the liquid storage bottle (51).
7. The expanded polytetrafluoroethylene product preforming equipment according to claim 1, characterized in that: A cleaning member (9) is also provided in the cabinet (1), and the cleaning member (9) comprises: A water absorbing block (91) is arranged on the engraving table (2) and is in contact with the top surface of the engraving table (2); The driving rod (92) is plugged into the water absorbing block (91) and is slidably connected to the engraving table (2) to drive the water absorbing block (91) to move.