Adhesive tube film attachment process

Abstract

The application discloses a rubber tube film-attached processing method and belongs to the technical field of rubber tube processing. The method comprises the following steps: transferring an inner covering film to a mold core of an injection molding machine by using a mechanical hand; and performing injection molding processing by using the injection molding machine to obtain a rubber tube with an inner covering film on the inner side wall. The mechanical hand comprises a first mounting bracket, a first sliding rail extending along an X axis is arranged on the first mounting bracket, a first sliding block is arranged on the first sliding rail, a second sliding rail extending along a Y axis is arranged on the first sliding block, a second sliding block and a third sliding block are arranged on the second sliding rail, a third sliding rail and a fourth sliding rail extending along a Z axis are respectively arranged on the second sliding block and the third sliding block, a fourth sliding block and a fifth sliding block are respectively arranged on the third sliding rail and the fourth sliding rail, a film sucking assembly is arranged on the fourth sliding block, and a film temporary storage assembly is arranged on the fifth sliding block. The rubber tube prepared by the method has the inner covering film on the inner side wall, and the storage time of the rubber material can be effectively prolonged under the premise of ensuring the use effect and use quality of the rubber material.

Description

Technical Field

[0001] This invention relates to the field of rubber tube processing technology, and in particular to a method for applying a film to a rubber tube. Background Technology

[0002] Silicone sealant is a widely used adhesive and sealant, especially in the construction and decoration industries, where it is an indispensable material. Silicone sealant products come in various packaging forms, but plastic tubs are currently the most common, typically 300ml or 600ml. These tubs usually consist of a tube with a dispensing nozzle at the front and a bottom cap (also called a piston) at the rear. During use, the bottom cap is pressed into the tube using a caulking gun. External pressure changes the volume of the tube, pushing the sealant out of the nozzle and ensuring full contact between the sealant and the surfaces of the materials to be bonded.

[0003] In existing technologies, the main material used for rubber cartridges is plastic. Although plastic cartridges offer good sealing, chemical resistance, and lightweight properties, effectively protecting the rubber from environmental pollution and damage, the performance of plastic (such as moisture resistance and oxidation resistance) is limited. After long-term storage in the cartridge, the rubber is prone to expansion and hardening, leading to reduced performance and quality, and a relatively short shelf life. To address this issue, a feasible solution is to add an inner liner to the inner wall of the cartridge. This inner liner adheres to the inner wall of the cartridge during injection molding. However, no dedicated processing equipment or method for this is currently available in the technology. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a method for attaching a film to a rubber tube, so as to adhere the inner film to the inner wall of the rubber tube during the injection molding process.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A method for applying a film to a rubber tubing, utilizing a rubber tubing film application system, the system comprising a robotic arm and an injection molding machine, the method comprising: Step S1: Use a robotic arm to transfer the inner film to the mold core of the injection molding machine; Step S2: The injection molding machine performs injection molding to obtain a rubber tube with an inner film on the inner wall; The robotic arm includes a first mounting bracket, on which a first slide rail extends along the X-axis, a first slider is mounted on the first slide rail, a second slide rail extends along the Y-axis on the first slider, a second slider and a third slider are mounted on the second slide rail, a third slide rail and a fourth slide rail extend along the Z-axis on the second slider and the third slider respectively, a fourth slider and a fifth slider are mounted on the third slide rail and the fourth slide rail respectively, a film suction assembly is mounted on the fourth slider, and a film storage assembly is mounted on the fifth slider, wherein the X-axis is perpendicular to the length direction of the injection molding machine; The membrane absorption assembly includes an adsorption rod, which has a plurality of first adsorption grooves for adsorbing the inner membrane onto the surface of the adsorption rod, and a first cavity communicating with the first adsorption grooves inside the adsorption rod. The membrane storage assembly includes a cylindrical component with openings at both ends for receiving and temporarily storing the inner membrane transferred by the adsorption rod. The cylindrical component, the adsorption rod, and the mold core of the injection molding machine are arranged in parallel, and the inner diameter of the cylindrical component is larger than the outer diameter of the adsorption rod and the mold core.

[0006] The present invention has the following beneficial effects: The film-coating processing method for rubber tubes of the present invention can use a robotic arm to transfer the inner film onto the mold core of the injection molding machine. After the rubber tube is injection molded according to conventional processes, the inner wall of the injection-molded rubber tube will naturally have the inner film (that is, the inner film adheres to the inner wall of the rubber tube during the injection molding process). This effectively protects the rubber material from pollution and damage from the external environment, reduces the occurrence of deterioration phenomena such as expansion and curing of the rubber material, and effectively extends the storage time of the rubber material while ensuring the use effect and quality of the rubber material. Attached Figure Description

[0007] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the oblique cross-section of the adhesive tube after the membrane is applied in this invention; Figure 2 for Figure 1 Schematic diagram of the inner membrane structure; Figure 3 The three-dimensional structure of the robotic arm in this invention Figure 1 ; Figure 4 The three-dimensional structure of the robotic arm in this invention Figure 2 ; Figure 5 This is a schematic diagram of the membrane absorption assembly in this invention; Figure 6 This is a schematic diagram of the membrane storage component in this invention; Figure 7 This is the three-dimensional structure of the film coating processing system for rubber tubes in this invention. Figure 1 ; Figure 8 This is the three-dimensional structure of the film coating processing system for rubber tubes in this invention. Figure 2 ; Figure 9 This is a schematic diagram of the molding assembly of the injection molding machine in this invention; Figure 10 This is a schematic diagram of the mold core of the injection molding machine in this invention; Figure 11 This is a schematic diagram of the telescopic component on the injection molding machine mold core in this invention; Figure 12 for Figure 11 The diagram shows an enlarged view of the telescopic component when the front end of the mold core is hidden. Figure 13 for Figure 11 The diagram shows the structure of the telescopic component when it is extended from the mold core. Figure 14 This is a photograph of a defective rubber tube after film coating processing in this invention, taken from one angle. Figure 15 This is a photograph of a defective rubber tube after film coating processing in this invention from another angle. Figure 16 This is a schematic diagram of the inner membrane structure in this invention; Figure 17 This is a schematic diagram of the membrane supply device in this invention; Figure 18 This is a schematic diagram of the membrane suction assembly taking membrane from the membrane supply device in this invention. Figure 19 This is a schematic diagram illustrating the operation of the membrane absorption assembly transferring the inner membrane to the membrane storage assembly in this invention. Figure 20 This is a schematic diagram illustrating the operation of the film storage component in this invention, which transfers the inner film to the injection molding machine mold core. Figure 21 This is a schematic flowchart of the film coating process for the rubber sleeve of the present invention.

[0008] Figure label: 100. Robotic arm; 300. Injection molding machine; 400. Glue cartridge film coating system. 11. First mounting bracket; 12. First slide rail; 13. First slider; 14. Second slide rail; 15. Second slider; 16. Third slider; 17. Third slide rail; 18. Fourth slide rail; 19. Fourth slider; 20. Fifth slider. 21. Membrane adsorption assembly; 211. Adsorption rod; 212. First adsorption tank; 22. Membrane temporary storage assembly; 221. Cylindrical component; 2211. A pair of semi-rings; 2212. Base block; 222. Second adsorption tank. 30. Molding assembly; 31. Front template; 32. Middle template; 33. Rear template; 34. Mold core; 341. Third suction groove; 342. Third cavity; 343. Circumferential groove; 344a. First arc-shaped component; 344b. Second arc-shaped component; 345. Fourth cavity; 35. Opening. 40. Film supply device; 41. Film storage assembly; 411. Base; 412. Lifting drive device; 413. Film placement platform; 414. Stop post; 42. Film delivery assembly; 421. Substrate; 422. Suction cup; 43. Second mounting bracket; 44. Fifth slide rail; 45. Sixth slider. 5. Glue tube, 51. Inner liner, 511. Connecting layer, 512. Separating layer, 513. Protective layer, 514. First adhesive layer, 515. Second adhesive layer, 52. Tube body, 53. Glue nozzle. Detailed Implementation

[0009] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0010] In existing technologies, the main material used for rubber cartridges is plastic. Although plastic cartridges offer good sealing, chemical resistance, and lightweight properties, effectively protecting the rubber from environmental pollution and damage, the performance of plastic (such as moisture resistance and oxidation resistance) is limited. After long-term storage in the cartridge, the rubber is prone to expansion and hardening, leading to reduced performance and quality, and a relatively short shelf life. To address this issue, a feasible solution is to add an inner liner to the inner wall of the cartridge. This inner liner adheres to the inner wall of the cartridge during injection molding. However, no dedicated processing equipment or method for this is currently available in the technology.

[0011] In this invention, such as Figure 1-2 As shown, the glue cartridge 5 after processing and film application includes a cartridge body 52, a glue outlet 53 at the front end of the cartridge body 52, a bottom cover (not shown) at the rear end of the cartridge body 52, and an inner film 51 on the side wall of the cartridge body 52.

[0012] Optionally, the inner membrane 51 includes a connecting layer 511 and an isolation layer 512 in sequence from the outside to the inside along the thickness direction. In addition, a protective layer 513 may be provided on the inner side of the isolation layer 512. The isolation layer 512 is made of metal, while the connecting layer 511 and the protective layer 513 are made of non-metallic materials.

[0013] The connecting layer 511 serves to connect with the side wall of the cylinder 52. Preferably, it is made of the same material as the cylinder 52, namely PE (polyethylene). Thus, the inner liner 51 self-adheses (without additional adhesive) to the inner side wall of the cylinder 52 during injection molding. Specifically, the cut inner liner 51 can be wrapped around the mold core 34 of the injection molding machine 300. After injection molding of the cylinder 52, the inner liner 51 naturally adheres to the inner side wall of the cylinder 52. PE is a thermoplastic resin, and its processing temperature range is highly compatible with commonly used plastic materials for cylinder injection molding (such as PP, PE, ABS, etc.). During the injection molding process of the cylinder 52, the PE connecting layer 511 in its high-temperature molten state can quickly wet and fuse with the molten plastic on the inner wall of the cylinder 52, forming a strong molecular-level bond after cooling. The connection is tight, and the process is simple.

[0014] The isolation layer 512 can be made of various metals, such as copper and stainless steel. However, considering both cost and barrier effect, aluminum foil is preferred. Aluminum foil has outstanding barrier performance and can completely block oxygen and water vapor, effectively preventing external oxygen and water vapor from entering the cylinder 52 and avoiding oxidation and deterioration of the adhesive stored in the cylinder. It can also block light exposure, greatly extending the shelf life of the adhesive. In addition, aluminum foil has a certain degree of ductility and toughness. When combined with the non-metallic connecting layer 511 and protective layer 513, it can improve the overall structural strength of the inner coating 51.

[0015] The protective layer 513 is mainly used to protect the isolation layer 512 and prevent the white oil and other auxiliary materials (such as 30 glue and 31 glue) in certain adhesives (such as acidic glass glue, neutral transparent glue, MS glue, etc.) from corroding the isolation layer 512. Therefore, the protective layer 513 is preferably a PET (polyethylene terephthalate, abbreviated as polyester) layer or a PBT (polybutylene terephthalate) layer. Both PET and PBT are high-strength engineering plastics with excellent wear resistance, scratch resistance and impact resistance. As the innermost layer of the inner film 51 (directly in contact or rubbed with the adhesive in the cylinder), it can effectively resist the friction and impact of the adhesive, prevent the aluminum foil isolation layer 512 from being damaged, and extend the service life of the entire inner film 51.

[0016] Furthermore, a first adhesive layer 514 may be provided between the connecting layer 511 and the isolation layer 512, and a second adhesive layer 515 may be provided between the isolation layer 512 and the protective layer 513. This can improve the bonding strength between dissimilar materials and prevent interlayer delamination. The first adhesive layer 514 and the second adhesive layer 515 can be made of various common adhesives in the art, such as polyurethane adhesive.

[0017] At this point, the thickness of the connecting layer 511 can be 10μm-30μm, such as 15μm, 20μm, 25μm, etc.; the thickness of the separating layer 512 can be 5μm-10μm, such as 7μm, 8μm, 9μm, etc.; the thickness of the protective layer 513 can be 5μm-20μm, such as 12μm, 15μm, 18μm, etc.; and the thickness of the first adhesive layer 514 and the second adhesive layer 515 can both be 5μm-10μm, such as 6μm, 7μm, 8μm, etc. In other words, the overall thickness of the inner coating 51 can be 30μm-80μm. Thus, the five-layer composite design of the inner coating 51, while ensuring an extended shelf life, also controls the overall thickness and does not affect the capacity of the adhesive cartridge 5.

[0018] The inner liner 51 can be made using a composite process. Specifically, an adhesive can be applied to the surface of the connecting layer 511 near the insulating layer 512 to form a first adhesive layer 514, and an adhesive can be applied to the surface of the protective layer 513 near the insulating layer 512 to form a second adhesive layer 515. Then, the connecting layer 511 (with the first adhesive layer 514), the insulating layer 512, and the protective layer 513 (with the second adhesive layer 515) can be joined together using a composite process.

[0019] Thus, by setting an inner liner 51 on the inner wall of the cylinder 52, the rubber compound can be effectively protected from pollution and damage from the external environment, reducing the deterioration of the rubber compound such as expansion and curing, and effectively extending the storage time of the rubber compound while ensuring the performance and quality of the rubber compound.

[0020] It is understood that the structure of the inner membrane 51 described above is only an example. The present invention is not limited to this structure. Other structures that are easy for those skilled in the art to conceive of can also be used, and none of them will affect the implementation of the present technical solution.

[0021] This invention provides a method for coating a film onto a rubber tub, utilizing a rubber tub coating system 400, which includes a robotic arm 100 and an injection molding machine 300, such as... Figure 21 As shown, the method includes: Step S1: Use the robotic arm 100 to transfer the inner film 51 to the mold core 34 of the injection molding machine 300; Step S2: The injection molding machine 300 performs injection molding to obtain a rubber tube 5 with an inner film 51 on the inner wall; The robotic arm 100 is used to transfer the inner liner 51 (to be attached) to the mold core 34 of the injection molding machine 300, such as... Figure 3-6 As shown, the system includes a first mounting bracket 11, a first slide rail 12 extending along the X-axis on the first mounting bracket 11, a first slider 13 on the first slide rail 12, a second slide rail 14 extending along the Y-axis on the first slider 13, a second slider 15 and a third slider 16 on the second slide rail 14, a third slide rail 17 and a fourth slide rail 18 extending along the Z-axis on the second slider 15 and the third slider 16 respectively, a fourth slider 19 and a fifth slider 20 on the third slide rail 17 and the fourth slide rail 18 respectively, a film suction assembly 21 on the fourth slider 19, and a film temporary storage assembly 22 on the fifth slider 20. The X-axis is perpendicular to the length direction of the injection molding machine 300 (see [reference]). Figure 7 In other words, the Y-axis is parallel to the length direction of the injection molding machine 300 / mold core 34; it can be understood that the X-axis and Y-axis are in the horizontal plane, and the Z-axis extends vertically; The membrane suction assembly 21 is used to suction the inner covering film 51, including an adsorption rod 211. The adsorption rod 211 is provided with a plurality of first adsorption grooves 212 for adsorbing the inner covering film 51 onto the surface of the adsorption rod 211. The adsorption rod 211 is provided with a first cavity (not shown) that communicates with the first adsorption grooves 212. The film storage assembly 22 is used to temporarily store the inner film 51 on the inner surface of the cylindrical part 221, and then transfer it to the mold core 34 of the injection molding machine 300. The film storage assembly 22 includes a cylindrical part 221 with openings at both ends for receiving and temporarily storing the inner film 51 transferred by the adsorption rod 211. The cylindrical part 221, the adsorption rod 211 and the mold core 34 of the injection molding machine 300 are arranged in parallel. The inner diameter of the cylindrical part 221 is larger than the outer diameter of the adsorption rod 211 and the mold core 34.

[0022] In use, the film suction assembly 21 first picks up the inner film 51 to be attached. Then, the slider moves on the slide rail, driving the film suction assembly 21 to move and transfer the inner film 51 to the film storage assembly 22. After that, the film storage assembly 22 moves to transfer the inner film 51 to the mold core 34 of the injection molding machine 300. Specifically, the inner film 51 can be placed (automatically or manually) on the surface of the suction rod 211, and a negative pressure is generated in the first cavity, so that the first suction groove 212 firmly adsorbs the inner film 51 onto the surface of the suction rod 211. Then, the film suction assembly 21 moves upward to align the suction rod 211 with the cylindrical part 221 (see...). Figure 19The inner film 51 is released from the first cavity of the suction rod 211 and inserted into the cylindrical part 221. The suction rod 211 is then withdrawn from the cylindrical part 221, thereby leaving / transferring the inner film 51 inside the cylindrical part 221. Afterward, the film storage assembly 22 moves to the opening 35 above the injection molding machine 300. Then, the film storage assembly 22 descends to align the cylindrical part 221 with the mold core 34 of the injection molding machine 300, and moves the cylindrical part 221 laterally onto the mold core 34 of the injection molding machine 300 (see...). Figure 20 At this point, the mold core 34 of the injection molding machine 300 adsorbs the inner film 51 onto the outer surface of the mold core 34. Finally, the cylindrical part 221 detaches from the mold core 34, and the film storage component 22 exits the injection molding machine 300 (at this point, all the previous related processes correspond to step S1). The injection molding machine 300 performs injection molding of the rubber cylinder 5 according to the conventional process (this process corresponds to step S2). Since the surface of the mold core 34 already has the inner film 51, the inner wall of the rubber cylinder 5 naturally has the inner film 51 after injection molding.

[0023] The film coating processing method of the present invention can use a robot arm 100 to transfer the inner film 51 to the mold core 34 of the injection molding machine 300. After the injection molding of the rubber tube 5 is carried out according to the conventional process, the inner sidewall of the injection molded rubber tube 5 will naturally have the inner film 51.

[0024] In some embodiments of the present invention, such as Figure 5-6 As shown, the first adsorption groove 212 is an annular groove located on the outer periphery of the adsorption rod 211. The width of the first adsorption groove 212 is 1mm-3mm, such as 1.5mm, 2mm, 2.5mm, etc. The difference between the inner diameter of the cylindrical component 221 and the outer diameter of the mold core 34, and the difference between the inner diameter of the cylindrical component 221 and the outer diameter of the adsorption rod 211, are both 1mm-5mm, such as 2mm, 3mm, 4mm, etc. It can be understood that the outer diameter of the adsorption rod 211 can be equal to the outer diameter of the mold core 34, or slightly larger or slightly smaller than the outer diameter of the mold core 34; the length of the adsorption rod 211 can be greater than or equal to the length of the mold core 34; and the length of the cylindrical component 221 can be less than or equal to the length of the mold core 34.

[0025] In some embodiments of the present invention, such as Figure 6 As shown, the inner surface of the cylindrical component 221 is provided with a second adsorption groove 222, and the side wall of the cylindrical component 221 is provided with a second cavity (not shown) that communicates with the second adsorption groove 222. Thus, when the adsorption rod 211 carrying the inner film 51 is inserted into the cylindrical component 221, after the first cavity on the adsorption rod 211 releases the air and releases the inner film 51, a negative pressure can be generated in the second cavity. As a result, the second adsorption groove 222 firmly adsorbs the inner film 51 onto the inner surface of the cylindrical component 221, improving the convenience of transferring the inner film 51.

[0026] In some embodiments of the present invention, such as Figure 6As shown, the cylindrical component 221 includes a pair of opposing semi-rings 2211. Each of the two semi-rings 2211 has a base block 2212 at the center of its relatively distant side. The fifth slider 20 is equipped with a driving device (not shown) that drives the base blocks 2212 to move the pair of semi-rings 2211 relative to each other. It can be understood that, in this case, the second adsorption groove 222 and the second cavity are respectively located on the pair of semi-rings 2211. Thus, the inner diameter of the cylindrical component 221 can be adjusted according to different size specifications of the rubber sleeve 5 / mold core 34, improving the adaptability of product manufacturing.

[0027] In some embodiments of the present invention, such as Figure 7-9 As shown, the film-attached processing system 400 for rubber tubes includes an injection molding machine 300 and the aforementioned robotic arm 100. The injection molding machine 300 includes a molding assembly 30, which includes a front template 31 (mainly used to cooperate with the mold core 34 to form the front wall of the rubber tube 5), a middle template 32 (mainly used to cooperate with the mold core 34 to form the side wall of the rubber tube 5), and a rear template 33 arranged sequentially. The front template 31 is fixedly set, the middle template 32 is fixedly connected to the front template 31, and the rear template 33 is slidably set with the mold core 34 (made of metal) fixed on it. The front template 31, the middle template 32, and the rear template 33 together form the cavity of the rubber tube. The injection molding machine 300 has an opening 35 above the molding assembly 30 for the film storage assembly 22 to enter.

[0028] Understandably, the rest of the injection molding machine 300 (including injection, hydraulic transmission, control, etc.) is the same as existing technology and will not be described in detail here. The robot arm 100 can be installed and fixed on the ground, or it can be fixed near the opening 35 on the injection molding machine 300 as shown in the figure.

[0029] Unlike existing technologies where the middle template is fixedly connected to the rear template, in this invention, to facilitate the film application process, the middle template 32 is fixedly connected to the front template 31. Thus, after mold opening, the rear template 33 can move a certain distance backward relative to the front template 31 and the middle template 32, thereby fully exposing the mold core 34 on the rear template 33. This allows sufficient space for the cylindrical part 221 to extend into the injection molding machine 300 and be fitted onto the mold core 34, thus smoothly transferring the inner film 51 to the surface of the mold core 34. Afterward, the injection molding of the rubber tube 5 is carried out according to the conventional process. Since the surface of the mold core 34 already has the inner film 51, the inner wall of the rubber tube 5 naturally has the inner film 51 after injection molding.

[0030] In this invention, the inner liner 51 can be firmly attached to the surface of the mold core 34 in the following ways.

[0031] Method 1 (Negative Pressure Adsorption): like Figure 10As shown, the mold core 34 is provided with a third adsorption groove 341 for adsorbing the inner coating film 51 onto the surface of the mold core 34, and a third cavity 342 connected to the third adsorption groove 341 is provided inside the mold core 34. At this time, referring to the aforementioned film-attaching process of the rubber sleeve 5, after the cylindrical part 221 transfers the inner coating film 51 to the surface of the mold core 34, a negative pressure is generated in the third cavity 342, so that the third adsorption groove 341 firmly adsorbs the inner coating film 51 onto the surface of the mold core 34, preparing for the subsequent injection molding process.

[0032] The third adsorption groove 341 can be an annular groove provided on the outer periphery of the mold core 34. The width of the third adsorption groove 341 is less than or equal to 1 mm, preferably 0.1 mm to 0.5 mm, such as 0.2 mm, 0.3 mm, 0.4 mm, etc. The width of the third adsorption groove 341 should not be too large or too small. If it is too large, it will easily cause local wrinkles in the inner film 51, affecting the film application effect. If it is too small, the annular groove will be difficult to process and the adsorption force will be insufficient.

[0033] Method 2 (electrostatic adsorption): The inner wall of the cylindrical part 221 is provided with an electrostatic plate (not shown) for applying static electricity to the inner film 51. The mold core 34 is electrically connected to a high-voltage electric application device (not shown). The mold core 34 is fixed to the rear template 33 by an insulating component. In specific implementation, after the inner film 51 is transferred from the adsorption rod 211 into the cylindrical part 221, a voltage of 5kV-50kV can be applied to the electrostatic plate to generate static electricity on the aluminum foil isolation layer 512 of the inner film 51. Then, when the cylindrical part 221 carrying the inner film 51 is fitted onto the mold core 34 of the injection molding machine 300, the high-voltage electric application device can be used to energize the mold core 34, so that the inner film 51 is electrostatically adsorbed and firmly fixed on the surface of the mold core 34, which facilitates the subsequent injection molding process.

[0034] Method 3 (Negative pressure adsorption + electrostatic adsorption): It can be conceivable that the above-mentioned implementation method one and implementation method two can be used simultaneously. Specifically, negative pressure adsorption can be used first to adsorb the inner film 51 onto the surface of the mold core 34, and then electrostatic adsorption can be used to firmly fix the inner film 51 onto the surface of the mold core 34. During the injection molding process of the rubber tube 5, the negative pressure adsorption can be turned off, and only the electrostatic adsorption force can be used to keep the inner film 51 fixed on the surface of the mold core 34. This method has the best effect.

[0035] During the production process, the inventors discovered that there is a small probability that the film-coated plastic tube 5 may have defects, namely, the inner film 51 fails to adhere to the inner wall of the plastic tube 5, but instead runs to the outer wall of the plastic tube 5. This is because the molten plastic is gradually squeezed into the plastic tube cavity from front to back under greater pressure. When the adsorption force of the mold core 34 on the inner film 51 (especially on the inner film 51 at the front edge of the mold core 34) is insufficient, this problem is likely to occur.

[0036] To address the above problems, in some embodiments of the present invention, such as Figure 11-13 As shown, the front end of the mold core 34 may be provided with a circumferential annular groove 343, and the inner film 51 is attached to the rear of the circumferential annular groove 343. The circumferential annular groove 343 is provided with a telescopic component 344 that can be hidden in the circumferential annular groove 343 and is in the shape of a ring. The telescopic component 344 includes a pair of first arc-shaped members 344a arranged opposite each other, and a pair of second arc-shaped members 344b is provided between the two ends of the pair of first arc-shaped members 344a. The two end faces of the pair of second arc-shaped members 344b are both inclined surfaces that gradually narrow from the inside to the outside. The shape of the two end faces of the pair of first arc-shaped members 344a is adapted to the end face shape of the corresponding second arc-shaped members 344b. The mold core 34 is provided with a pushing device for pushing the pair of second arc-shaped members 344b to move outward, and a resetting device for resetting the pair of first arc-shaped members 344a and the pair of second arc-shaped members 344b.

[0037] In this embodiment, initially, the telescopic component 344 is hidden within the circumferential annular groove 343, so that the surface of the mold core 34 remains flat (e.g., Figure 12 (As shown); After the injection molding process begins, the pushing device pushes a pair of second arc-shaped parts 344b outwards from the surface of the mold core 34. Since the first arc-shaped parts 344a and the second arc-shaped parts 344b are connected by inclined surfaces, the pair of first arc-shaped parts 344a are also squeezed outwards from the surface of the mold core 34, so that the pair of first arc-shaped parts 344a and the pair of second arc-shaped parts 344b form annular protrusions that protect the inner coating 51 (as shown). Figure 13 (As shown); after the molten plastic passes over the pair of first arc-shaped parts 344a and the pair of second arc-shaped parts 344b, the molten plastic naturally presses the inner liner 51 onto the surface of the mold core 34. At this point, the pushing force can be removed, allowing the pair of first arc-shaped parts 344a and the pair of second arc-shaped parts 344b to return to their original positions. The space occupied by the arc-shaped parts will later be filled by the molten plastic. In this way, the problem of the inner liner 51 failing to adhere to the inner wall of the glue tube 5 and instead ending up on the outer wall of the glue tube 5 can be effectively solved.

[0038] In this embodiment, the first arc-shaped component 344a and the second arc-shaped component 344b are connected by an inclined surface, providing good sealing and preventing molten plastic from flowing in and affecting the long-term use of the telescopic component 344. It is understood that the circumferential groove 343 on the mold core 34 is not connected to the third cavity 342; the pushing device can be any mechanical drive type in the art, such as a lever radially driving the arc-shaped component, or a rotating rod with a cam pushing the arc-shaped component to move, etc. Figure 10 The reference numeral 345 is the fourth cavity through which the pushing device passes; the reset device can also be any kind of mechanical drive in the field, such as a reverse pushing device, a reset spring pulling reset, etc.

[0039] The inventors also discovered during the production process that the coated rubber tube 5 has a certain probability of developing another defect: the portion of the inner film 51 near the front of the rubber tube 5 adheres normally, but the portion near the rear of the rubber tube 5 fails to adhere to the inner wall of the rubber tube 5, instead partially migrating to the outer wall of the rubber tube 5. Figure 14-15 As shown. To solve this problem, in some embodiments of the present invention, such as Figure 16 As shown, along the length of the rubber tube 5, the inner liner 51 has 2-5 notches 511 on both sides of its edge. The notches 511 can be of various shapes, such as V-shaped, semi-circular, U-shaped, straight, etc. The size of the notches 511 can be flexibly set according to actual needs, and the depth is preferably 1mm-5mm; the notches 511 on both sides of the inner liner 51 are preferably staggered.

[0040] In-depth research revealed that the above-mentioned problems are caused by the following: In order for the inner liner 51 to cover the entire inner surface of the plastic tube 5, the width of the inner liner 51 needs to be slightly larger than the circumference of the inner cavity of the plastic tube 5. That is, there is a partial overlap on both sides of the inner liner 51 in the plastic tube 5. For this overlapping part, there is a problem that the adsorption force of the mold core 34 is slightly insufficient. At the same time, there is internal stress / tension after the inner liner 51 is wound on the mold core 34. In particular, the molding of the plastic tube 5 is done sequentially from front to back. When the molten plastic is injected into the plastic tube cavity to squeeze the inner liner 51 at the front of the mold core 34, but before the inner liner 51 at the rear of the mold core 34 is squeezed, the part of the inner liner 51 near the rear of the mold core 34 is prone to slightly opening outward under the squeezing force of the molten plastic. This causes a small amount of molten plastic to enter the inner side of the opened inner liner 51, thus producing the above-mentioned defects. In this embodiment, by providing 2-5 notches 511 on both sides of the inner film 51, the tension on both sides of the inner film 51 can be better released, reducing the probability of such defective products from about 20% to almost zero.

[0041] In some embodiments of the present invention, such as Figure 7-8 , Figure 17-18 As shown, the film-coating system 400 also includes a film supply device 40, which includes a film storage assembly 41 and a film delivery assembly 42, wherein: The film storage assembly 41 includes a base 411, a lifting drive device 412 is provided in the middle of the base 411, the lifting drive device 412 is connected to the film placement platform 413, and a number of baffles 414 are provided on the base 411 at the edge of the film placement platform 413. The film placement platform 413 and the baffles 414 together form a receiving space for placing the inner covering film 51. The film delivery assembly 42 includes a substrate 421 located above and opposite to the film delivery platform 413. The lower surface of the substrate 421 is provided with suction cups 422 at the four corners of the inner film 51. The film coating processing system 400 also includes a second mounting bracket 43, on which a fifth slide rail 44 extending along the Y-axis is provided, and a sixth slider 45 is provided on the fifth slide rail 44, and the film loading and unloading assembly 42 (i.e., substrate 421) is fixed to the sixth slider 45.

[0042] In this invention, the inner film 51 is a sheet material, pre-cut into rectangles of the required size, and placed on the film placement platform 413. In use, firstly, the sixth slider 45 moves the film delivery assembly 42 above the film placement platform 413. Then, the lifting drive device 412 rises and lifts the film placement platform 413, bringing the inner film 51 on the platform closer to the suction cup 422 on the lower surface of the substrate 421 of the film delivery assembly 42. Afterward, the suction cup 422 adsorbs the uppermost inner film 51, and then, driven by the sixth slider 45, resets and moves above the adsorption rod 211 (see...). Figure 18 In this embodiment, the membrane suction assembly 21 is provided with four suction rods 211. Each time, two inner covering films 51 are transferred to two of the suction rods 211. Finally, the suction cup 422 is released, and the suction rods 211 generate adsorption force, automatically adsorbing and wrapping the inner covering film 51 around the surface of the suction rods 211. In this way, continuous automatic film picking and feeding to the suction rods 211 can be realized, which facilitates the implementation of automated production and improves production efficiency.

[0043] In summary, the film-coating processing method for plastic tubing of the present invention utilizes a robotic arm 100 to transfer the inner film 51 onto the mold core 34 of the injection molding machine 300. After injection molding of the plastic tubing 5 using conventional processes, the inner wall of the injection-molded tubing 5 naturally bears the inner film 51, effectively protecting the plastic material from environmental pollution and damage, reducing deterioration phenomena such as expansion and curing, and effectively extending the storage time of the plastic material while ensuring its performance and quality. In the prior art, the shelf life of plastic material stored in plastic tubing is typically 9 months; with the solution of the present invention, it can reach 2 years, significantly extending the shelf life.

[0044] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0045] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0046] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0047] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A method for coating a film onto a rubber tube, utilizing a rubber tube coating system, characterized in that, The film coating processing system for the rubber tube includes a robotic arm and an injection molding machine, and the method includes: Step S1: Use a robotic arm to transfer the inner film to the mold core of the injection molding machine; Step S2: The injection molding machine performs injection molding to obtain a rubber tube with an inner film on the inner wall; The robotic arm includes a first mounting bracket, on which a first slide rail extends along the X-axis, a first slider is mounted on the first slide rail, a second slide rail extends along the Y-axis on the first slider, a second slider and a third slider are mounted on the second slide rail, a third slide rail and a fourth slide rail extend along the Z-axis on the second slider and the third slider respectively, a fourth slider and a fifth slider are mounted on the third slide rail and the fourth slide rail respectively, a film suction assembly is mounted on the fourth slider, and a film storage assembly is mounted on the fifth slider, wherein the X-axis is perpendicular to the length direction of the injection molding machine; The membrane absorption assembly includes an adsorption rod, which has a plurality of first adsorption grooves for adsorbing the inner membrane onto the surface of the adsorption rod, and a first cavity communicating with the first adsorption grooves inside the adsorption rod. The membrane storage assembly includes a cylindrical component with openings at both ends for receiving and temporarily storing the inner membrane transferred by the adsorption rod. The cylindrical component, the adsorption rod, and the mold core of the injection molding machine are arranged in parallel, and the inner diameter of the cylindrical component is larger than the outer diameter of the adsorption rod and the mold core.

2. The method for applying a film to a rubber tube according to claim 1, characterized in that, The first adsorption groove is an annular groove provided on the outer periphery of the adsorption rod, and the width of the first adsorption groove is 1mm-3mm; And / or, the difference between the inner diameter of the cylindrical component and the outer diameter of the mold core is 1mm-5mm; And / or, the difference between the inner diameter of the cylindrical component and the outer diameter of the adsorption rod is 1mm-5mm.

3. The method for applying a film to a rubber tube according to claim 1, characterized in that, The inner surface of the cylindrical component is provided with a second adsorption groove, and the side wall of the cylindrical component is provided with a second cavity that communicates with the second adsorption groove.

4. The method for applying a film to a rubber tube according to claim 3, characterized in that, The cylindrical component includes a pair of opposing semi-rings, each of which has a base block at the center of its opposite side. The fifth slider is provided with a driving device that drives the base blocks to move the pair of semi-rings relative to each other.

5. The method for applying a film to a rubber sleeve according to any one of claims 1-4, characterized in that, The injection molding machine includes a molding assembly, which includes a front mold plate, a middle mold plate, and a rear mold plate arranged sequentially. The front mold plate is fixedly arranged, the middle mold plate is fixedly connected to the front mold plate, and the rear mold plate is slidably arranged with a mold core fixed thereon. The front mold plate, the middle mold plate, and the rear mold plate together form a cylindrical cavity. The injection molding machine has an opening above the molding assembly for the film storage assembly to enter.

6. The method for applying a film to a rubber tube according to claim 5, characterized in that, The mold core is provided with a third adsorption groove for adsorbing the inner film onto the surface of the mold core, and the mold core is provided with a third cavity that communicates with the third adsorption groove.

7. The method for applying a film to a rubber sleeve according to claim 6, characterized in that, The third adsorption groove is an annular groove located on the outer periphery of the mold core, and the width of the third adsorption groove is less than or equal to 1 mm.

8. The method for applying a film to a rubber tube according to claim 6, characterized in that, The inner wall of the cylindrical component is provided with an electrostatic plate for applying static electricity to the inner film. The mold core is electrically connected to a high-voltage electric application device. The mold core is fixed to the rear template by an insulating component.

9. The method for applying a film to a rubber tube according to claim 6, characterized in that, The front end of the mold core is provided with a circumferential annular groove, and the inner liner is attached to the rear of the circumferential annular groove. The circumferential annular groove is provided with a telescopic component that can be hidden within the groove and is circular in shape. The telescopic component includes a pair of first arc-shaped members arranged opposite each other, and a pair of second arc-shaped members are provided between the two ends of the pair of first arc-shaped members. Both end faces of the pair of second arc-shaped members are inclined surfaces that gradually narrow from the inside to the outside. The shape of the end faces of the pair of first arc-shaped members is adapted to the end face shape of the corresponding second arc-shaped members. The mold core is provided with a pushing device for pushing the pair of second arc-shaped members outward, and a resetting device for resetting the pair of first arc-shaped members and the pair of second arc-shaped members. And / or, along the length of the rubber tube, the inner liner has 2-5 notches on both sides of its edge.

10. The method for applying a film to a rubber tube according to claim 5, characterized in that, The film-coating system for rubber tubes further includes a film supply device, which comprises a film storage assembly and a film delivery assembly, wherein: The film storage assembly includes a base, a lifting drive device is provided in the middle of the base, the lifting drive device is driven to connect to a film placement platform, and a number of baffles are provided on the base at the edge of the film placement platform. The film placement platform and the baffles together form a receiving space for placing the inner film. The film delivery assembly includes a substrate located above the film placement platform and opposite to the film placement platform, and suction cups are provided on the lower surface of the substrate corresponding to the four corners of the inner film. The film coating processing system also includes a second mounting bracket, on which a fifth slide rail extending along the Y-axis is provided, and a sixth slider is provided on the fifth slide rail, and the film delivery assembly is fixed to the sixth slider.

Images