Continuous extrusion method of double-color prefabricated pipe blank

Abstract

The invention discloses a continuous extrusion method of a double-color prefabricated pipe blank. The continuous extrusion method comprises the following steps: taking polytetrafluoroethylene cured materials with a color A and a color B which are the same in weight, and respectively adding into a charging cavity I and a charging cavity II; applying pressure to the thrust rod to obtain two semicircular pre-pressed blanks located on the two sides of the baffle pre-pressed section respectively; the bottom baffle is detached from the bottom of the extrusion charging barrel; taking polytetrafluoroethylene cured materials with the color A and the color B with the same weight, and respectively adding into a charging cavity I and a charging cavity II; pressure is applied to the thrust rod, the bottom check block is slowly pushed out of the extrusion material barrel till the bottom check block is completely separated from the extrusion material barrel, and at the moment, a pipe blank extruded from an outlet in the bottom of the extrusion material barrel is a circular-ring-column-shaped double-color prefabricated pipe blank; according to the continuous extrusion device, cured materials with different colors can be added into the continuous extrusion device to be continuously extruded to prepare the double-color prefabricated pipe blank, the uniformity, the uniformity and the color uniformity of the extruded double-color prefabricated pipe blank are more excellent, the overall efficiency is high, and the yield is high.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and specifically to a continuous extrusion method for a two-color preformed tube blank, that is, a continuous extrusion method for a two-color spiral preformed tube blank. Background Art

[0002] Polytetrafluoroethylene (PTFE) materials have characteristics such as hydrophobicity, chemical stability, and low friction coefficient. When a two-color film made of it is coated on the surface of a guide wire tube, it not only makes the guide wire tube have good lubricity and is convenient for moving in the human body cavity, but also can realize the two-color imaging function, facilitating doctors to observe the position and movement state of the guide wire tube during the operation.

[0003] In the prior art, the preparation of a PTFE two-color tube blank is a relatively cumbersome preparation process. First, the PTFE dispersion resin mixed with colored paste A is put into a semi-circular mold for pre-forming to obtain a semi-circular ring-shaped blank of color A; the PTFE dispersion resin mixed with colored paste B is put into the same semi-circular mold for pre-forming to obtain a semi-circular ring-shaped blank of color B; the semi-circular ring-shaped blanks of color A and color B with the same size are surrounded and butted to obtain a two-color ring-shaped tube blank, and then it is added into an extruder through a special feeding device, and a uniform two-color preformed tube blank (also called a two-color spiral preformed tube blank) is extruded through the extruder. The two-color preformed tube blank then goes through some specific steps to become a two-color threaded tube. The above preparation method of the two-color preformed tube blank has a complex process, and there are also unfavorable factors such as uncontrollable impurities during the mold installation process and difficult mold disassembly and assembly, resulting in too low overall efficiency and low product yield. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a continuous extrusion method for a two-color preformed tube blank in view of the above-mentioned prior art. This continuous extrusion method for a two-color preformed tube blank can add different-colored cured materials into a continuous extrusion device and prepare a PTFE two-color preformed tube blank through continuous extrusion. The neatness, uniformity, and color uniformity of the extruded two-color preformed tube blank are more excellent, with high overall efficiency and high product yield.

[0005] To achieve the above technical purpose, the technical solution adopted by the present invention is as follows:

[0006] A continuous extrusion method for a two-color preformed tube blank, comprising:

[0007] Using a continuous extrusion device composed of an extrusion barrel 4, a special baffle 3, a feeding device 2, a thrust rod 1, an outer frame support 6, a bottom block 7, and a bottom baffle 8;

[0008] The extrusion barrel 4 is connected to the outer frame bracket 6. The bottom block 7 is located in the inner hole of the extrusion barrel 4, and the outer wall of the bottom block 7 is in sliding contact with the inner hole wall of the extrusion barrel 4. The bottom of the extrusion barrel 4 is connected with a bottom baffle 8 for limiting the bottom block 7. The top of the extrusion barrel 4 is located in the bottom inner hole of the feeding device 2, and the inner hole wall of the bottom of the feeding device 2 is in sliding contact with the outer circular wall of the top of the extrusion barrel 4. The special baffle 3 includes a baffle feeding section 301, a baffle pre-pressing section 302 and a baffle forming section 303 connected in sequence. The baffle feeding section 301 of the special baffle 3 contacts the feeding device 2, the baffle pre-pressing section 302 of the special baffle 3 contacts the inner hole wall of the extrusion barrel 4, and the baffle feeding section 301 and the baffle pre-pressing section 302 of the special baffle 3 divide the cavity jointly formed by the feeding device 2 and the extrusion barrel 4 into a first feeding cavity 12 and a second feeding cavity 13. The baffle forming section 303 of the special baffle 3 is in sliding contact with the inner hole wall of the bottom block 7. The center lines of the feeding device 2, the special baffle 3, the extrusion barrel 4 and the bottom block 7 are all on the same straight line;

[0009] A slot 101 along its length direction and penetrating one end thereof is formed in the middle of the thrust rod 1. The slot 101 of the thrust rod 1 can be in sliding contact with both the baffle feeding section 301 and the baffle pre-pressing section 302 of the special baffle 3, and the thrust rod 1 can extend into the interior of the extrusion barrel 4;

[0010] Extrusion steps:

[0011] B1. Take the same weight of A-color PTFE cured material and B-color PTFE cured material. The A-color PTFE cured material is added to the first feeding cavity, and the B-color PTFE cured material is added to the second feeding cavity;

[0012] B2. Align the slot of the thrust rod 1 with the special baffle, align the bottom of the thrust rod with the inner hole of the extrusion barrel, apply downward pressure to the thrust rod. The outer wall of the thrust rod is in sliding contact with the inner hole wall of the extrusion barrel, and two semi-circular pre-pressed blanks located on both sides of the baffle pre-pressing section are obtained in the cavity;

[0013] B3. Remove the bottom baffle from the bottom of the extrusion barrel; lift the thrust rod; take the same weight of A-color PTFE cured material and B-color PTFE cured material. The A-color PTFE cured material is added to the first feeding cavity, and the B-color PTFE cured material is added to the second feeding cavity;

[0014] B6. Align the slot of the thrust rod with the special baffle, align the bottom of the thrust rod with the inner hole of the extrusion barrel, apply downward pressure to the thrust rod, and the bottom of the thrust rod squeezes the two semi-circular preforms, causing the two semi-circular preforms to move downward and be extruded and formed with the inner surface of the extrusion barrel. The two semi-circular preforms jointly fill the gap generated after the bottom block moves downward, and slowly push the bottom block out of the extrusion barrel until the bottom block completely disengages from the extrusion barrel. At this time, the tube blank extruded from the bottom outlet of the extrusion barrel is a circular columnar two-color prefabricated tube blank.

[0015] As a further improved technical solution of the present invention, after step B6, there is a step: B7. Lift the thrust rod; take A-color polytetrafluoroethylene cured material and B-color polytetrafluoroethylene cured material of the same weight, add the A-color polytetrafluoroethylene cured material to the first feeding cavity, and add the B-color polytetrafluoroethylene cured material to the second feeding cavity; align the slot of the thrust rod with the special baffle, align the bottom of the thrust rod with the inner hole of the extrusion barrel, apply downward pressure to the thrust rod, so that the two semi-circular preforms located on both sides of the pre-pressing section of the baffle are extruded and formed with the inner surface of the extrusion barrel, and then are slowly extruded from the bottom of the extrusion barrel, and finally a circular columnar two-color prefabricated tube blank is extruded.

[0016] B8. Repeat step B7 to obtain a continuous circular columnar two-color prefabricated tube blank.

[0017] As a further improved technical solution of the present invention, it further includes a fixed flange. There are installation through holes provided on the outer frame bracket, and the extrusion barrel passes through the installation through holes on the outer frame bracket and is connected to the outer frame bracket through the fixed flange and locking screws.

[0018] As a further improved technical solution of the present invention, the outer circumferential wall of the bottom block is in sliding and sealing contact with the inner hole wall of the extrusion barrel.

[0019] As a further improved technical solution of the present invention, there are two symmetric pin blind holes provided on the outer circumferential wall of the bottom of the extrusion barrel. Each pin blind hole is connected with a pin, and the bottom baffle is suspended below the two pins to limit the bottom of the bottom block.

[0020] As a further improved technical solution of the present invention, the inner hole wall of the bottom of the feeding device is in sliding and sealing contact with the outer wall of the top of the extrusion barrel.

[0021] As a further improved technical solution of the present invention, the feeding device includes a funnel-shaped feeding section and a barrel connection section. There is a strip-shaped placement groove provided on the outer wall of the funnel-shaped feeding section. The baffle feeding section is wider at the top and narrower at the bottom, and the outer wall of the baffle feeding section is in sliding and sealing contact with the strip-shaped placement groove of the funnel feeding section. The bottom of the baffle feeding section is placed on the top of the extrusion barrel, and the pre-pressing section of the baffle extends into the inner hole of the extrusion barrel, and the pre-pressing section of the baffle is in sliding and sealing contact with the inner hole wall of the extrusion barrel.

[0022] As a further improved technical solution of the present invention, the outer wall of the baffle forming section of the special baffle is in sliding and sealing contact with the inner hole wall of the bottom baffle block.

[0023] As a further improved technical solution of the present invention, the slot length of the thrust rod is greater than the total length of the baffle feeding section and the baffle pre-pressing section of the special baffle. The inner wall of the slot of the thrust rod can be in sliding and sealing contact with both the baffle feeding section and the baffle pre-pressing section of the special baffle, and the outer wall of the thrust rod is in sliding and sealing contact with the inner hole wall of the extrusion barrel.

[0024] The beneficial effects of the present invention are as follows:

[0025] The continuous extrusion method of the double-color prefabricated pipe blank of the present invention includes a feeding device, an extrusion barrel, a special baffle, a thrust rod, etc. Two kinds of polytetrafluoroethylene cured materials with different colors and the same weight, under the downward thrust applied by the thrust rod, make the polytetrafluoroethylene cured materials pass through the feeding section, pre-forming section, and forming section composed of the extrusion barrel, the special baffle, and the feeding device, and directly obtain an annular columnar double-color prefabricated pipe blank (i.e., a double-color spiral prefabricated pipe blank), that is, a PTFE blank pipe. There are no complex mold disassembly and assembly steps in the whole process. Only by repeating the movement of the thrust rod and adding polytetrafluoroethylene cured materials with the same weight, the double-color spiral prefabricated pipe blank that can be directly added to the extruder can be continuously obtained. And this device can continuously extrude stably and reliably. Compared with the previous preparation method, the preparation process of this continuous extrusion method is also simple and efficient, which can avoid the mistakes of a large number of manual steps and greatly improve the operation efficiency. This continuous extrusion method adds different-color mixed materials to the continuous extrusion device and can directly prepare the polytetrafluoroethylene double-color spiral pipe blank, that is, the double-color pipe blank, through continuous extrusion. The continuous extrusion method of the double-color prefabricated pipe blank of the present invention can continuously extrude the double-color prefabricated pipe blank; the neatness, uniformity, and color uniformity of the extruded double-color prefabricated pipe blank are more excellent. Description of the Drawings

[0026] Figure 1 It is a three-dimensional structural view of the continuous extrusion device of the present invention when it is prepared.

[0027] Figure 2 It is a schematic cross-sectional view of the structure of the continuous extrusion device of the present invention when it is prepared.

[0028] Figure 3 It is a plan view of the structure of the special baffle in the continuous extrusion device of the present invention.

[0029] Figure 4 It is a three-dimensional structural view of the special baffle in the continuous extrusion device of the present invention.

[0030] Figure 5 It is a three-dimensional structural view of the thrust rod in the continuous extrusion device of the present invention.

[0031] Figure 6 This is a three-dimensional structural view of the feeding device in the continuous extrusion device of the present invention.

[0032] Figure 7 This is a three-dimensional structural view of the continuous extrusion device of the present invention during operation.

[0033] Figure 8 This is a schematic cross-sectional view of the continuous extrusion device of the present invention during operation.

[0034] Figure 9 This is a schematic view of the material cavity of the continuous extrusion device of the present invention during operation. Detailed implementation manners

[0035] The following further describes the detailed implementation manners of the present invention with reference to the accompanying drawings:

[0036] As Figure 1 shown, a continuous extrusion device for a two-color prefabricated pipe blank includes an extrusion barrel 4, a special baffle 3, a feeding device 2, a thrust rod 1, an outer frame support 6, a bottom block 7, and a bottom baffle 8.

[0037] As Figure 1-2 shown, the extrusion barrel 4 is connected to the outer frame support 6. The bottom block 7 is cylindrical, and the bottom block 7 is located in the cylindrical inner hole of the extrusion barrel 4, and the outer wall of the bottom block 7 is in sliding contact with the inner hole wall of the extrusion barrel 4. A bottom baffle 8 for limiting the bottom block 7 is connected to the bottom of the extrusion barrel 4. The top of the extrusion barrel 4 is located in the bottom inner hole of the feeding device 2, in contact with the step of the bottom inner hole of the feeding device 2, and the inner hole wall of the bottom of the feeding device 2 is in sliding contact with the outer circular wall of the top of the extrusion barrel 4. A special baffle 3 is provided inside the feeding device 2. The baffle feeding section 301 of the special baffle 3 is in sliding contact with the feeding device 2. The baffle pre-pressing section 302 of the special baffle 3 is in sliding contact with the inner hole wall of the extrusion barrel 4. The outer circular wall of the cylindrical baffle forming section 303 of the special baffle 3 is in sliding contact with the inner hole wall of the bottom block 7. The bottom of the baffle pre-pressing section 302 of the special baffle 3 is in contact with the top of the bottom block 7. The center lines of the feeding device 2, the special baffle 3, the extrusion barrel 4, and the bottom block 7 are all on the same straight line;

[0038] As Figure 5 shown, the thrust rod 1 has a cylindrical shape. A slot 101 extending along its length direction and penetrating the bottom end is provided in the middle of the thrust rod 1. The inner wall of the slot 101 of the thrust rod 1 can be in sliding contact with the surfaces of both the baffle feeding section 301 and the baffle pre-pressing section 302 of the special baffle 3, and the thrust rod 1 can extend into the inside of the extrusion barrel 4. The outer circular wall of the thrust rod 1 is in sliding contact with the inner hole wall of the extrusion barrel 4.

[0039] This embodiment further includes a fixed flange 5. An installation through-hole is provided on the outer frame bracket 6. After the extrusion barrel 4 passes through the installation through-hole on the outer frame bracket 6, the connection groove 401 of the extrusion barrel 4 is connected to the outer frame bracket 6 through the fixed flange 5 and the locking screw 9.

[0040] In this embodiment, the outer circular wall of the bottom stop block 7 is in sliding and sealing contact with the inner hole wall of the extrusion barrel 4. Specific sliding and sealing method: The outer circular wall of the bottom stop block 7 and the inner hole wall of the extrusion barrel 4 can be processed smoother to achieve sealed sliding contact.

[0041] In this embodiment, two symmetric pin blind holes are provided on the outer circular wall at the bottom of the extrusion barrel 4. A pin 11 is connected in each pin blind hole. The pin 11 is made of metal. The bottom baffle 8 is suspended below the two pins 11 and is used to limit the bottom of the bottom stop block 7 to prevent the bottom stop block 7 from falling.

[0042] In this embodiment, the inner hole wall at the bottom of the feeding device 2 is in sliding and sealing contact with the outer circular wall at the top of the extrusion barrel 4.

[0043] In this embodiment, as Figure 3-4 shown, the special baffle 3 includes a baffle feeding section 301, a baffle pre-pressing section 302, and a baffle forming section 303 connected in sequence. The baffle feeding section 301 is wider at the top and narrower at the bottom. The baffle pre-pressing section 302 is rectangular, and the baffle forming section 303 is bar-shaped and cylindrical. As Figure 6 shown, the feeding device 2 includes a funnel-shaped feeding section 201 and a barrel connection section 202. A strip-shaped placement groove 203 is provided on the outer wall of the funnel-shaped feeding section 201. The baffle feeding section 301 is wider at the top and narrower at the bottom, and the outer side wall of the baffle feeding section 301 is in sliding and sealing contact with the strip-shaped placement groove 203 of the funnel feeding section 201. The bottom of the baffle feeding section 301 is placed on the top of the extrusion barrel 4, and the baffle pre-pressing section 302 extends into the inner hole of the extrusion barrel 4. The baffle pre-pressing section 302 is in sliding and sealing contact with the inner hole wall of the extrusion barrel 4.

[0044] In this embodiment, the outer wall of the baffle forming section 303 of the special baffle 3 is in sliding and sealing contact with the inner hole wall of the bottom stop block 7.

[0045] In this embodiment, as Figure 5 shown, the length of the slot 101 of the thrust rod 1 is greater than the total length of the baffle feeding section 301 and the baffle pre-pressing section 302 of the special baffle 3. The inner wall of the slot 101 of the thrust rod 1 can be in sliding and sealing contact with both the baffle feeding section 301 and the baffle pre-pressing section 302 of the special baffle 3, and the outer wall of the thrust rod 1 is in sliding and sealing contact with the inner hole wall of the extrusion barrel 4.

[0046] The extrusion barrel 4 is a hollow cylindrical mold. It is necessary to ensure that the inner wall of the hollow part is smooth. There is a connection groove 401 on the outer wall for connecting and fixing the flange 5. There are symmetrical pin blind holes at the lower part of the outer wall for installing pins 11 (metal pins) to ensure the connection strength of the bottom baffle 8. The top is connected to the bottom of the feeding device 2 to ensure that the center lines of the two components are on the same straight line. The special baffle 3 is a special hard thin metal piece, which is divided into three sections, namely the baffle feeding section 301, the baffle preforming section 302, and the baffle forming section 303. The shapes and functions of each section are different. The baffle feeding section 301 is used to prevent the two-color cured materials from being mixed with each other. The baffle preforming section 302 is where the two different-color cured materials are respectively compressed in their respective material cavities (i.e., the first material cavity 12 and the second material cavity 13). The baffle forming section 303 is a solid cylinder where the two different-color cured materials are fused. The special baffle 3 is connected to the feeding device 2 to ensure that the center lines of the two components are on the same straight line. The special baffle 3 is kept in a sliding connection with the extrusion barrel 4. Figure 1 In Figure 1 , after the special baffle 3 is placed inside the feeding device 2, the bottom of the special baffle 3 is flush with the bottom of the extrusion barrel 4. The feeding device 2 is a feeding mold in the shape of a flared opening, with a placement groove 203 in the center for placing the special baffle 3. The bottom of the feeding device 2 is in a sliding connection with the extrusion barrel 4. The bottom block 7 is a hollow cylindrical block. The outer wall of the bottom block 7 is smooth and fits the inner wall of the extrusion barrel 4, and the inner wall of the bottom block 7 is also smooth and fits the outer wall of the baffle forming section 303 of the special baffle 3. The smoothness enables a sealed sliding contact. The bottom baffle 8 is a metal bent part that cooperates with the pin 11 installed in the pin blind hole on the lower part of the outer wall of the extrusion barrel 4, mainly used to block the fall of the bottom block 7, so that the cured material inside the barrel can reach its due compressed volume and strength. The thrust rod 1 is a solid long cylindrical push rod with a hollow groove, mainly used to apply a downward thrust so that the cured material can be formed through three forming areas to become the double-color spiral preform tube blank we need. The outer frame bracket 6 is a C-shaped mounting bracket, with 4 threaded holes for connecting to the fixed flange 5 at the top and an installation through hole for the extrusion barrel 4 to pass through, mainly used for fixing the extrusion barrel 4.

[0047] The preparatory work before preparation is that the whole set of parts is in accordance with Figure 1Perform the assembly to ensure that all the components mentioned below are clean, tidy and free of burrs. The outer frame bracket 6 contacts the workbench surface to lift the overall tooling, facilitating subsequent operations. The outer frame bracket 6 and the extrusion barrel 4 are positioned and installed through the fixed flange 5 and then fixed by the locking screw 9. The inner hole of the extrusion barrel 4 and the outer wall of the bottom block 7 are in sliding fit, and symmetric pin blind holes are left below the outer wall of the extrusion barrel 4 for installing the pins 11. Then, a special bottom baffle 8 is suspended below the two metal pins 11. The bottom baffle 8 is provided with a suspension groove for suspending below the two metal pins 11 to limit the bottom of the bottom block 7; The feeding device 2 and the extrusion barrel 4 are in sliding fit. The feeding device 2 is placed on the top of the extrusion barrel 4. Finally, a special baffle 3 is placed in the feeding device 4. The baffle feeding section 301 of the special baffle 3 is in sliding fit with the feeding device 2, the baffle pre-pressing section 302 of the special baffle 3 is in sliding fit with the inner wall of the extrusion barrel 4, and the baffle forming section 303 of the special baffle 3 is in sliding fit with the inner wall of the bottom block 7, ensuring that the center lines of the feeding device 2, the special baffle 3, the barrel 4, and the bottom block 7 are all on the same straight line. The assembled device is as shown in Figure 1 shown, and can be divided into two feeding chambers of the same size, namely the feeding chamber one 12 and the feeding chamber two 13 as shown in Figure 9 shown, through the special baffle 3 for standby. The schematic diagram of the material chamber when the assembled device is working is as shown in Figure 9 shown. The whole material chamber is divided into a feeding section, a preforming section, and a forming section.

[0048] Prepare N grams each of A and B color polytetrafluoroethylene cured materials of the same weight. The A and B color polytetrafluoroethylene cured materials are respectively added to the feeding chamber completed by assembly. Apply pressure downward through the push rod 1 to obtain 2 semi-circular pre-pressed blanks in the middle of the device; Remove the bottom baffle 8, lift the push rod 1, and add N grams each of A and B color polytetrafluoroethylene cured materials again. Apply pressure through the push rod 1. After the preformed blank is extruded and formed with the inner surface of the extrusion barrel 4 to fill the gap, slowly push the bottom block 7 out of the extrusion barrel 4 until the bottom block 7 is completely separated from the extrusion barrel 4. Repeating the above actions can obtain a continuous double-color circular columnar tube blank, that is, the double-color prefabricated tube blank 10 as shown in Figure 7-8 shown.

[0049] Based on the above continuous extrusion device, a continuous extrusion method for double-color prefabricated tube blanks is provided, including:

[0050] Steps for assembling the continuous extrusion device:

[0051] A1. Connect the extrusion barrel 4 to the outer frame bracket 6; A2. Removably connect the bottom baffle 8 to the bottom of the extrusion barrel 4; At the same time, place the bottom block 7 in the inner hole of the extrusion barrel 4, and the outer wall of the bottom block 7 is in sliding contact with the inner hole of the extrusion barrel 4;

[0052] A3. Place the feeding device 2 on top of the extrusion barrel 4 such that the top of the extrusion barrel 4 is located within the bottom inner hole of the feeding device 2. At the same time, the inner wall of the bottom inner hole of the feeding device 2 is in sliding contact with the outer circular wall of the top of the extrusion barrel 4; A4. Place the special baffle 3 in the feeding device 2. The baffle feeding section 301 of the special baffle 3 is in sliding contact with the feeding device 2. The baffle pre-pressing section 302 of the special baffle 3 is in sliding contact with the inner wall of the extrusion barrel 4. The baffle forming section 303 of the special baffle 3 is in sliding contact with the inner wall of the bottom block 7, ensuring that the centerlines of the feeding device 2, the special baffle 3, the extrusion barrel 4, and the bottom block 7 are all on the same straight line; The special baffle 3 divides the cavity jointly formed by the feeding device 2 and the extrusion barrel 4 into a first feeding cavity 12 and a second feeding cavity 13;

[0053] Extrusion steps of the continuous extrusion device:

[0054] B1. Take the A-color PTFE cured material and the B-color PTFE cured material of the same weight. Add the A-color PTFE cured material to the first feeding cavity 12 and the B-color PTFE cured material to the second feeding cavity 13;

[0055] B2. Align the slot 101 of the thrust rod 1 with the special baffle 3 and the bottom of the thrust rod 1 with the inner hole of the extrusion barrel 4. Apply downward pressure to the thrust rod 1. The outer wall of the thrust rod 1 is in sliding contact with the inner wall of the extrusion barrel 4, and two semi-circular pre-pressed blanks located on both sides of the baffle pre-pressing section 302 are obtained within the cavity;

[0056] B3. Remove the bottom baffle 8 from the bottom of the extrusion barrel 4; Lift the thrust rod 1; Take the A-color PTFE cured material and the B-color PTFE cured material of the same weight. Add the A-color PTFE cured material to the first feeding cavity 12 and the B-color PTFE cured material to the second feeding cavity 13;

[0057] B6. Align the slot 101 of the thrust rod 1 with the special baffle 3 and the bottom of the thrust rod 1 with the inner hole of the extrusion barrel 4. Apply downward pressure to the thrust rod 1. The bottom of the thrust rod 1 squeezes the two semi-circular pre-pressed blanks, causing the two semi-circular pre-pressed blanks to move downward and be extrusion-molded with the inner surface of the extrusion barrel 4. The two semi-circular pre-pressed blanks jointly fill the gap generated after the bottom block 7 moves downward, and slowly push the bottom block 7 out of the extrusion barrel 4 until the bottom block 7 is completely separated from the extrusion barrel 4. At this time, the tubular blank extruded from the bottom outlet of the extrusion barrel 4 is a circular ring-shaped double-color prefabricated tubular blank;

[0058] B7. Then, lift the thrust rod 1; take PTFE cured materials of color A and color B with the same weight, add the PTFE cured material of color A into the first feeding chamber 12, and add the PTFE cured material of color B into the second feeding chamber 13; align the slot 101 of the thrust rod 1 with the special baffle 3, align the bottom of the thrust rod 1 with the inner hole of the extrusion barrel 4, apply downward pressure to the thrust rod 1, so that the two semi-circular preforms located on both sides of the baffle pre-pressing section 302 are extruded and formed with the inner surface of the extrusion barrel 4, and then are slowly extruded from the bottom of the extrusion barrel 4, and finally a circular ring-shaped double-color preform tube blank is extruded.

[0059] B8. Repeat step B7 to obtain a continuous circular ring-shaped double-color preform tube blank.

[0060] The continuous extrusion device for the double-color preform tube blank of the present invention mainly consists of a feeding device 2, an extrusion barrel 4, a special baffle 3, a thrust rod 1, etc. Two PTFE cured materials with different colors and the same weight, under the downward thrust applied by the thrust rod 1, pass through the feeding section, preforming section and forming section composed of the extrusion barrel 4, special baffle 3 and feeding device 2 as shown, and directly obtain the double-color preform tube blank 10 (i.e., double-color spiral preform tube blank), that is, the PTFE blank tube. There is no complex mold disassembly and assembly process in the whole process. Only by repeating the movement of the thrust rod 1 and adding PTFE cured materials with the same weight, the double-color spiral preform tube blank that can be directly added to the extruder can be continuously obtained. And this device can continuously extrude stably and reliably. Compared with the previous preparation device, the structure of this continuous extrusion device is novel and simple, and the preparation process of this continuous extrusion device is also simple and efficient, which can avoid the mistakes of a large number of manual steps and greatly improve the operation efficiency. Figure 9 The protection scope of the present invention includes but is not limited to the above embodiments. The protection scope of the present invention is subject to the claims. Any replacement, deformation and improvement that are easily conceivable by those skilled in the art to this technology fall within the protection scope of the present invention.

[0061] The protection scope of the present invention includes but is not limited to the above embodiments. The protection scope of the present invention is subject to the claims. Any replacement, deformation and improvement that are easily conceivable by those skilled in the art to this technology fall within the protection scope of the present invention.

Claims

1. A method for continuous extrusion of a two-color prefabricated tube, characterized in that: include: A continuous extrusion device comprising an extrusion barrel (4), a special baffle (3), a feeding device (2), a thrust rod (1), an outer frame bracket (6), a bottom baffle (7) and a bottom baffle (8); The extrusion barrel (4) is connected to the outer frame bracket (6); the bottom stopper (7) is located in the inner hole of the extrusion barrel (4) and the outer wall of the bottom stopper (7) is in sliding contact with the inner hole wall of the extrusion barrel (4); the bottom of the extrusion barrel (4) is connected to a bottom baffle (8) for limiting the bottom stopper (7); the top of the extrusion barrel (4) is located in the bottom inner hole of the feeding device (2); the bottom inner hole wall of the feeding device (2) is in sliding contact with the outer circular wall of the top of the extrusion barrel (4); the special baffle (3) includes a baffle feeding section (301), a baffle pre-pressing section (302) and a baffle forming section (303) which are connected in sequence. 3), the baffle feeding section (301) of the special baffle (3) contacts the feeding device (2), the baffle pre-pressing section (302) of the special baffle (3) contacts the inner hole wall of the extrusion barrel (4), the baffle feeding section (301) and the baffle pre-pressing section (302) of the special baffle (3) divide the cavity formed by the feeding device (2) and the extrusion barrel (4) into a feeding cavity 1 (12) and a feeding cavity 2 (13); the baffle forming section (303) of the special baffle (3) contacts the inner hole wall of the bottom baffle (7) in a sliding manner, and the center lines of the feeding device (2), the special baffle (3), the extrusion barrel (4) and the bottom baffle (7) are all on the same straight line; A slot (101) is provided in the middle of the thrust rod (1) along its length direction and penetrating one end thereof, the slot (101) of the thrust rod (1) can be in sliding contact with both the baffle feeding section (301) and the baffle pre-compression section (302) of the special baffle (3), and the thrust rod (1) can extend into the interior of the extrusion barrel (4); Extrusion steps: B1. Take the same weight of color A polytetrafluoroethylene mature material and color B polytetrafluoroethylene mature material, add color A polytetrafluoroethylene mature material into feeding chamber 1 (12), and add color B polytetrafluoroethylene mature material into feeding chamber 2 (13); B2, aligning the slot (101) of the thrust rod (1) with the special baffle (3), aligning the bottom of the thrust rod (1) with the inner hole of the extrusion barrel (4), applying downward pressure to the thrust rod (1), so that the outer wall of the thrust rod (1) and the inner hole wall of the extrusion barrel (4) are in sliding contact, and two semicircular pre-pressed blanks are obtained in the cavity, which are respectively located on both sides of the baffle pre-pressing section (302); B3. Remove the bottom baffle (8) from the bottom of the extrusion barrel (4); lift the thrust rod (1); take the same weight of color A polytetrafluoroethylene mature material and color B polytetrafluoroethylene mature material, add the color A polytetrafluoroethylene mature material to the feeding chamber 1 (12), and add the color B polytetrafluoroethylene mature material to the feeding chamber 2 (13); B6. Align the slot (101) of the thrust rod (1) with the special baffle (3), align the bottom of the thrust rod (1) with the inner hole of the extrusion barrel (4), apply downward pressure to the thrust rod (1), and squeeze two semicircular pre-pressed billets at the bottom of the thrust rod (1), so that the two semicircular pre-pressed billets move downward and are extruded with the inner surface of the extrusion barrel (4). The two semicircular pre-pressed billets together fill the gap formed by the downward movement of the bottom stopper (7) inside the extrusion barrel (4), and slowly push the bottom stopper (7) out of the extrusion barrel (4) until the bottom stopper (7) is completely separated from the extrusion barrel (4). At this time, the tube billet extruded from the bottom outlet of the extrusion barrel (4) is a circular cylindrical two-color prefabricated tube billet.

2. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: Step B6 is followed by the steps: B7, lift the thrust rod (1); take the same weight of color A polytetrafluoroethylene mature material and color B polytetrafluoroethylene mature material, add the color A polytetrafluoroethylene mature material into the feeding chamber 1 (12), and add the color B polytetrafluoroethylene mature material into the feeding chamber 2 (13); align the slot (101) of the thrust rod (1) with the special baffle (3), align the bottom of the thrust rod (1) with the inner hole of the extrusion barrel (4), and apply pressure downward to the thrust rod (1), so that the two semicircular pre-pressed blanks located on both sides of the baffle pre-pressing section (302) are extruded with the inner surface of the extrusion barrel (4), and then slowly extruded from the bottom of the extrusion barrel (4), and finally a circular cylindrical two-color prefabricated tube blank is extruded; B8. Repeat step B7 to obtain a continuous circular cylindrical two-color prefabricated tube.

3. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: It also includes a fixing flange (5), and the outer frame bracket (6) is provided with a mounting through hole. The extrusion barrel (4) passes through the mounting through hole on the outer frame bracket (6) and is connected to the outer frame bracket (6) through the fixing flange (5) and the locking screw (9).

4. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: The outer circular wall of the bottom stopper (7) is in sliding sealing contact with the inner hole wall of the extrusion barrel (4).

5. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: The outer circular wall at the bottom of the extrusion barrel (4) is provided with two symmetrical pin blind holes, each of which is connected to a pin (11), and a bottom baffle (8) is suspended below the two pins (11) to limit the bottom of the bottom baffle (7).

6. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: The inner hole wall at the bottom of the feeding device (2) is in sliding sealing contact with the outer wall at the top of the extrusion barrel (4).

7. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: The feeding device (2) comprises a funnel-type feeding section (201) and a barrel connecting section (202); the outer wall of the funnel-type feeding section (201) is provided with a strip-shaped receiving groove (203); the baffle feeding section (301) is wide at the top and narrow at the bottom, and the outer wall of the baffle feeding section (301) is in sliding and sealing contact with the strip-shaped receiving groove (203) of the funnel feeding section (201); the bottom of the baffle feeding section (301) is placed on the top of the extrusion barrel (4), and the baffle pre-pressing section (302) extends into the inner hole of the extrusion barrel (4), and the baffle pre-pressing section (302) is in sliding and sealing contact with the inner hole wall of the extrusion barrel (4).

8. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: The outer wall of the baffle forming section (303) of the special baffle (3) is in sliding sealing contact with the inner hole wall of the bottom baffle (7).

9. The continuous extrusion method of a two-color prefabricated tube according to claim 1, characterized in that: The length of the slot (101) of the thrust rod (1) is greater than the total length of the baffle feeding section (301) and the baffle pre-pressing section (302) of the special baffle (3); the inner wall of the slot (101) of the thrust rod (1) can be in sliding and sealing contact with both the baffle feeding section (301) and the baffle pre-pressing section (302) of the special baffle (3), and the outer wall of the thrust rod (1) is in sliding and sealing contact with the inner hole wall of the extrusion barrel (4).

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