A traceless product double-color mold, working method and traceless double-color plastic part

Abstract

The application provides a traceless product double-color mold, a working method and a traceless double-color plastic part. The traceless product double-color mold comprises a first mold arranged at a first working position, a second mold arranged at a second working position, and a common mold module movable between the first working position and the second working position. The first mold comprises a first front mold core, a first rear mold core and a first wedge. The second mold comprises a second front mold core, a second rear mold core and a second wedge. The common mold module comprises a common rear mold and a common slider matched on the outside of the common rear mold. The common rear mold is provided with a mold hole for inserting the first rear mold core and the second rear mold core. When the first mold is opened, the first wedge drives the common slider to clamp and fix the hard rubber product on the common rear mold. When the first mold and the second mold are closed, the first wedge or the second wedge drives the common slider to loosen and avoid. The traceless product double-color mold has the advantages of compact structure, small volume, high production efficiency and good product quality.

Description

Technical Field

[0001] This invention relates to molds, and particularly to a two-color mold for seamless products, a working method thereof, and a two-color plastic part for seamless products. Background Technology

[0002] Existing high-end, two-color medical syringe plungers are made of seamless two-color plastic parts, requiring the product to have no parting lines or ejector pin marks, achieving an extremely seamless appearance. This requirement is very difficult to meet with ordinary mold technology.

[0003] Currently available two-color molds all require that the product structure of the post-mold portion of the first and second injections be completely identical. This ensures that after the first injection, the post-mold can rotate to the second injection position without moving the product, thus completing the two-color molding.

[0004] If the product structure results in completely different mold sections for the first and second injections, traditional two-color mold technology cannot achieve this. The biggest obstacle lies in products with different mold sections. After the first injection, the product needs to leave space for the second injection, so the product cannot be completely fixed to the mold, making it impossible for traditional two-color molds to achieve products with different mold sections.

[0005] Given the above requirements, when the product needs to be seamless and have a completely different product structure between the first and second injection molds, the existing two-color mold technology is even less able to meet the product requirements.

[0006] While overmolding can achieve seamless two-color injection molding, it requires making a hard plastic part first and then manually placing it into a soft plastic mold, which is inefficient. Secondly, because of the removal and re-placement process, there are at most two injection points. Otherwise, due to product consistency and the movement error of the hard plastic part, the sealing part between the hard and soft plastic parts cannot be perfect, and the product will have flash defects. Therefore, overmolding is not a truly good solution. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a seamless product injection molded part with a compact structure, low manufacturing cost, reliable operation and high molding quality, a seamless product two-color mold and its working method.

[0008] This invention provides a traceless two-color plastic part, comprising a hard plastic structure and a soft plastic structure. The hard plastic structure includes a rod 41 and a circular pressing plate 43 disposed at the lower end of the rod 41. The lower end surface of the pressing plate 43 is an inwardly concave arc surface, and the sidewall of the pressing plate 43 is a sloping surface, forming an inverted frustum structure with a larger upper end and a smaller lower end. The upper surface of the pressing plate 43 is provided with an annular groove, and the edge of the upper surface of the pressing plate 43 forms an annular protrusion 431. Multiple through holes penetrate between the annular groove and the arc surface. The soft plastic structure includes a first soft plastic layer 442 disposed on the arc surface, a second soft plastic layer 441 disposed in the annular groove, and a soft plastic column 443 disposed in the through holes and connecting the first soft plastic layer 442 and the second soft plastic layer 441.

[0009] Meanwhile, the present invention also provides a seamless product dual-color mold, which includes:

[0010] The first mold, set at the first station, is used for injection molding of hard plastic structures, including a first front mold core 11, a first rear mold core 12 and a first wedge 14;

[0011] The second mold, set at the second station, is used for injection molding of soft rubber structures, including a second front mold core 21, a second rear mold core 22, and a second wedge 24.

[0012] The common module 3, as a common end, can move between the first station and the second station, including a common rear mold 32 and a common slider 31 that slides on the outside of the common rear mold 32. The common rear mold 32 has a mold hole 320 for inserting the first rear mold core 12 and the second rear mold core 22.

[0013] When the first mold is being separated, the first wedge 14 drives the common slider 31 to clamp and fix the hard plastic product on the common rear mold 32.

[0014] When the first mold and the second mold are closed, the first wedge 14 or the second wedge 24 drives the common slider 31 to release and achieve avoidance.

[0015] Furthermore, the first wedge 14 can move along the mold closing and mold opening direction, and moves synchronously with the first front mold core 11 or the first rear mold core 12. After the first mold is opened, the first wedge 14 disengages from the common slider 31. The second wedge 24 can move along the mold closing and mold opening direction, and moves synchronously with the second front mold core 21 or the second rear mold core 22. After the second mold is opened, the second wedge 24 disengages from the common slider 31.

[0016] Furthermore, the common slider 31 is provided with oblique guide holes corresponding to the first oblique wedge 14 and the second oblique wedge 24. After the first oblique wedge 14 and the second oblique wedge 24 are inserted into the oblique guide holes, they can drive the common slider 31 to slide and achieve pressing and releasing.

[0017] Furthermore, the common slider 31 is provided with a first oblique guide hole 310 corresponding to the first oblique wedge 14 and a second oblique guide hole 311 corresponding to the second oblique wedge 24, the first oblique guide hole 310 and the second oblique guide hole 311 are oriented in opposite directions; the first oblique wedge 14 and the second oblique wedge 24 are respectively disposed at the upper and lower ends of the common module.

[0018] Furthermore, the end face of the rear mold 32 is provided as a partial molding surface for the hard plastic product and can support the hard plastic product after the first mold is separated.

[0019] Furthermore, the partially formed surface is used for forming the inclined sidewalls of the pressing plate.

[0020] Furthermore, the end of the common slider 31 is provided with a pressing surface 312 facing the common rear mold 32 and used to fit the edge top surface of the hard plastic product.

[0021] Furthermore, the sidewalls of the mold closing points of the first mold and the second mold are provided with clearance grooves for avoiding the common slider 31.

[0022] Furthermore, the mold closing direction of the first mold and the second mold is perpendicular to the horizontal plane, so that the injection molded product after mold separation is in a vertical state.

[0023] Furthermore, the first mold and the second mold are arranged in parallel, the common module 3 is connected to a rotating mechanism and can move between the first mold and the second mold, and the rotation axis of the common module 3 is parallel to the mold closing and mold opening directions.

[0024] Furthermore, the common module 3 consists of two sets that can move alternately between the first mold and the second mold.

[0025] Furthermore, the upper end and / or side wall of the rear mold 32 are provided with a first limiting part, and the common slider 31 is provided with a second limiting part. When the common slider 31 is in the pressing state, the second limiting part contacts the first part and achieves limiting.

[0026] Furthermore, the common slider 31 is provided with sliding damping, or the contact surface between the common slider 31 and the common rear mold 32 is a smooth surface and can be attracted when in contact.

[0027] Furthermore, the common sliders 31 are multiple and evenly distributed circumferentially.

[0028] Meanwhile, the present invention also provides a method for working a two-color mold for a seamless product, which includes the following steps:

[0029] S1. Reset, the common module 3 moves to the first station and is located between the first front mold core 11 and the first rear mold core 12;

[0030] S2. In the first mold closing, the first front mold core 11 and the first rear mold core 12 move towards each other to achieve mold closing. After mold closing, the first rear mold core 12 is located in the mold hole 320 of the common rear mold 32, and a first molding cavity for hard plastic structure molding is formed between the first rear mold core 12, the common rear mold 32 and the first front mold core 11.

[0031] During the mold closing process, the first wedge 14 moves along the mold closing direction and inserts into the inclined guide hole of the common slider 31, pushing the common slider 31 to move outward, thereby avoiding collision and providing space for the mold closing of the first mold;

[0032] S3. In a single injection, the first injection molding machine injects hard plastic material into the first molding cavity to complete the injection molding of the hard plastic structure.

[0033] S4. First cooling: Cool and shape the hard plastic structure to ensure its structural stability and achieve demolding strength.

[0034] S5. In one mold opening, the first front mold core 11 and the first rear mold core 12 move along the mold opening direction to achieve mold separation. After mold separation, the first rear mold core 12 is located outside the mold hole 320 of the common rear mold 32, and the hard plastic structure remains on the common rear mold 32.

[0035] During the mold parting process, the first wedge 14 moves along the mold parting direction, causing the common slider 31 to move inward, and the pressing surface 312 at the end of the common slider 31 presses against the upper edge of the hard plastic structure, thereby fixing the hard plastic product.

[0036] After the mold parting is completed, the first wedge 14 disengages from the common slider 31;

[0037] S6, Shifting: The drive mechanism moves the common module 3, carrying the hard plastic product, to the second station and positions it between the second front mold core 21 and the second rear mold core 22.

[0038] S7. Secondary mold closing: The second front mold core 21 and the second rear mold core 22 move towards each other to achieve mold closing. After mold closing, the second rear mold core 22 extends into the mold hole 320 of the common rear mold 32, and a second molding cavity for soft rubber structure molding is formed between the second rear mold core 22, the common rear mold 32 and the second front mold core 21.

[0039] During the mold closing process, the second wedge 24 moves along the mold closing direction and inserts into the inclined guide hole of the common slider 31, pushing the common slider 31 to move outward, releasing the pressure on the edge of the hard plastic product, and providing space for the second mold to close;

[0040] S8. Secondary injection: The second injection machine injects soft rubber material into the second molding cavity, so that it covers the surface of the hard rubber structure.

[0041] S9. Secondary cooling: Cooling and shaping the soft rubber product to ensure that the soft rubber and hard rubber are fully bonded and reach the demolding strength.

[0042] S14. Secondary mold opening: The second front mold core 21 and the second rear mold core 22 move in opposite directions to achieve mold separation. After mold separation, the second rear mold core 22 is located outside the mold hole 320 of the common rear mold 32, and the soft rubber covering the hard rubber product remains on the common rear mold 32.

[0043] During the mold parting process, the second wedge 24 moves along the mold parting direction and disengages from the common slider 31;

[0044] S11. Unloading: The formed product is removed from the common rear mold 32 by a robotic arm or air nozzle.

[0045] S12, Reset, the drive mechanism drives the common module 3 back to the first station.

[0046] Furthermore, in step S5, the common slider 31 is attached to the common rear mold under the action of damping or smooth surface adsorption, ensuring that no displacement occurs during the movement of the common module 3.

[0047] This invention relates to a seamless two-color mold for products. It features a common rear mold that works in conjunction with a movable common slider. This allows the hard plastic part, after being formed at the first station, to be transferred to the second station for soft plastic overmolding via the common module. This ensures zero displacement of the hard plastic part, effectively guaranteeing precise alignment of the mold cavity during both injection processes and improving product quality. During the transfer of the common module, the common slider adheres and secures the hard plastic part, preventing it from loosening due to vibration or displacement during the transfer. This ensures the hard plastic part remains precisely positioned upon entering the second station, further enhancing product quality. The entire process eliminates the need for manual handling of hard plastic parts; the common module automatically shifts, resulting in a short production cycle. The mold hole of the common rear mold can accommodate the insertion of the rear mold core from either the first or second mold, which have completely different molding surfaces. Regardless of whether the rear mold has a skeleton molding surface or an overmolding surface, mold closing and injection molding can be achieved, thus accommodating the two-color injection molding needs of various product structures and improving mold versatility. This seamless two-color mold for products is compact, small in size, highly efficient, and produces high-quality products. Attached Figure Description

[0048] Figure 1 A schematic diagram of the structure of a seamless two-color plastic part;

[0049] Figure 2 This is a schematic diagram of the structure of the first mold of the present invention;

[0050] Figure 3 This is a schematic diagram of the mold parting of the first mold of the present invention;

[0051] Figure 4 for Figure 3 Enlarged view of section A in the middle;

[0052] Figure 5 This is a schematic diagram of the structure of the second mold of the present invention;

[0053] Figure 6 This is a schematic diagram of the second mold closing mechanism of the present invention;

[0054] Figure 7 for Figure 6 Enlarged view of section B;

[0055] Figure 8 This is a schematic diagram of the parting of the second front mold core of the second mold of the present invention;

[0056] Figure 9 This is a schematic diagram of the mold parting of the second mold of the present invention;

[0057] Figure 10 This is a schematic diagram of the common module of the present invention located at the first workstation;

[0058] Figure 11 This is a schematic diagram of the operation of the first mold of the present invention.

[0059] In the diagram: 11. First front mold core, 12. First rear mold core, 14. First wedge, 21. Second front mold core, 22. Second rear mold core, 24. Second wedge, 3. Common module, 31. Common slider, 32. Common rear mold, 310. First oblique guide hole, 311. Second oblique guide hole, 312. Pressure surface, 320. Mold hole, 41. Rod body, 43. Pressing plate, 431. Annular protrusion, 441. Second soft rubber layer, 442. First soft rubber layer, 443. Soft rubber pillar. Detailed Implementation

[0060] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0061] See Figure 1This invention provides a seamless two-color plastic part, specifically, a plunger for a medical syringe, comprising a hard plastic structure and a soft plastic structure. The hard plastic structure includes a rod 41 and a circular pressing plate 43 disposed at the lower end of the rod 41. The lower end face of the pressing plate 43 is an inwardly concave arc surface, and the sidewalls of the pressing plate 43 are inclined, thus forming an inverted frustum structure with a larger upper end and a smaller lower end. An annular groove is provided on the upper surface of the pressing plate 43, which forms a groove along the edge of the upper surface of the pressing plate 43. An annular protrusion 431 is provided, and multiple through holes are provided between the annular groove and the arc-shaped surface. In this embodiment, there are multiple through holes, which are evenly distributed circumferentially. The soft rubber structure includes a first soft rubber layer 442, a second soft rubber layer 441, and a soft rubber pillar 443. The first soft rubber layer 442 is disposed on the surface of the arc-shaped surface, the second soft rubber layer 441 is disposed in the annular groove, and its edge extends to the upper surface of the annular protrusion 431. The soft rubber pillar is located in the through holes and is used to connect the first soft rubber layer 442 and the second soft rubber layer 441.

[0062] This seamless, two-color plastic component features a first soft rubber layer covering the curved concave surface at the lower end of the press plate. This ergonomic design allows for a more comfortable and gentle contact between the fingers and the soft rubber layer when medical personnel push the syringe, reducing fatigue during prolonged use. A second soft rubber layer is placed within an annular groove on the upper surface of the press plate, connected by a soft rubber pillar between the first and second layers, creating a continuous soft rubber structure. This significantly improves the bonding strength between the soft and hard rubber layers, effectively preventing the soft rubber layer from detaching or tearing during use. Furthermore, the beveled structure on the sidewalls of the press plate creates an inverted frustum shape, wider at the top and narrower at the bottom. This facilitates support and transfer of common modules during injection molding, enabling two-color (rubber) injection molding.

[0063] Meanwhile, the present invention also provides a seamless product dual-color mold, which includes a first mold, a second mold, and a common module 3, see reference. Figures 2-11 .

[0064] The first mold is set at the first station and is used for injection molding of hard plastic structures. The first mold includes a first front mold core 11, a first rear mold core 12 and a first wedge 14. Both the first rear mold core 12 and the first front mold core 11 can move to realize mold opening and mold separation.

[0065] The second mold is set at the second station and is used for injection molding of soft rubber structures. The second mold includes a second front mold core 21, a second rear mold core 22 and a second wedge 24. Both the second rear mold core 22 and the second front mold core 21 can move to realize mold opening and mold separation.

[0066] The common module 3 serves as a common end and can move between the first station and the second station. It includes a common rear mold 32 and a common slider 31 that slides on the outside of the common rear mold 32. There are multiple common sliders 31 and they are evenly distributed around the periphery. In this embodiment, the sliding direction of the common slider 31 is perpendicular to the mold closing or mold opening direction. A mold hole 320 is provided on the common rear mold 32. The mold hole 320 can accommodate the insertion of the first rear mold core 12 and the second rear mold core 22. After insertion, a complete molding surface is formed.

[0067] When the first mold is separated, the first wedge 14 drives the common slider 31 to clamp, thereby fixing the hard plastic product on the common rear mold 32 and preventing the hard plastic product on the common slider from loosening during the movement, which would affect the quality of the soft plastic molding at the rear.

[0068] When the first mold and the second mold are closed, the first wedge 14 or the second wedge 24 drives the common slider 31 to release and achieve avoidance;

[0069] When the first mold and the second mold are completely separated, the first wedge 14 or the second wedge 24 disengages from the common slider 31. At this time, the common module 3 is not connected to the first mold or the second mold, and can move between the first station and the second station to perform soft or hard plastic injection molding.

[0070] This application sets up a common rear mold, which works in conjunction with a movable common slider to allow the hard plastic to be transferred to the second station for soft plastic overmolding after being formed at the first station. This achieves zero displacement of the hard plastic, effectively ensuring precise alignment of the mold cavity during the two injection processes and improving product quality.

[0071] The mold hole 320 of the common rear mold 32 can accommodate the insertion of the rear mold core of the first mold or the second mold with completely different molding surfaces. Regardless of whether the rear mold is a skeleton molding surface or a covering molding surface, mold closing injection can be realized, thereby accommodating the two-color injection molding requirements of various product structures and improving the versatility of the mold.

[0072] When the mold is closed, the slider automatically releases to avoid collisions and ensure smooth injection molding. This reduces the slider's travel distance, improves response speed, and reduces the overall size of the common module.

[0073] During mold separation, the wedge disengages from the common slider, separating the common module from the first or second mold, thus enabling the common module to freely switch between the first and second stations to complete different injection molding processes.

[0074] When the common module is transferred, the rigid plastic product is attached and fixed by the common slider to prevent the product from loosening due to vibration or displacement during the transfer process. This ensures that the rigid plastic part remains in a precise position when it enters the second station, thus improving product quality. The entire process does not require manual handling of rigid plastic parts, as the common module moves automatically, resulting in a short production cycle.

[0075] This invention utilizes the coordinated operation of a common rear mold and a common slider to achieve the transfer of hard plastic molding to the second station for soft plastic coating along with the common module, ensuring precise alignment of the mold cavity between the two injection molding processes and effectively improving product consistency and yield. At the same time, this structure is compatible with mold switching for different molding surfaces, meeting the production needs of various types of two-color products and significantly enhancing mold versatility and production line flexibility. Its structure is compact, small in size, and highly flexible in use.

[0076] In this application, the first wedge 14 can move along the mold closing and mold parting direction, and it can move synchronously with the first front mold core 11 or the first rear mold core 12. After the first mold is parted, the first wedge 14 disengages from the common slider 31. The second wedge 24 can move along the mold closing and mold parting direction, and it can move synchronously with the second front mold core 21 or the second rear mold core 22. After the second mold is parted, the second wedge 24 disengages from the common slider 31.

[0077] The wedge moves synchronously with the first and second front mold cores or the rear mold core, directly using the rigid power of mold closing and mold opening to drive the slider. When the mold closes, the wedge inserts into the slider's inclined guide hole to push and avoid. When the mold opens, the wedge drives the slider to clamp. No additional power unit or control system is required, making the mold structure more compact, reducing the overall volume and manufacturing cost, while improving the reliability and response speed of the action. After the first and second molds are completely separated, the wedge moves synchronously with the mold core and disengages from the slider's inclined guide hole. The common module has no connection with the mold of the previous station, allowing the common module to move freely to another station by rotation or linear drive. The mold hole 320 can accommodate the insertion of front and rear mold cores with completely different structures, breaking through the core limitation that the rear mold structure of traditional two-color molds must be consistent.

[0078] In this embodiment, the common slider 31 is provided with oblique guide holes corresponding to the first wedge 14 and the second wedge 24. After the first wedge 14 and the second wedge 24 are inserted into the oblique guide holes, they can drive the common slider 31 to slide, thereby achieving pressing and releasing. In this embodiment, the common slider 31 is provided with a first oblique guide hole 310 corresponding to the first wedge 14 and a second oblique guide hole 311 corresponding to the second wedge 24. The first oblique guide hole 310 and the second oblique guide hole 311 are oblique holes and have opposite inclination directions. The first wedge 14 and the second wedge 24 are respectively provided at the upper and lower ends of the common module.

[0079] Traditional two-color mold slider drive mechanisms require space on the side or end face of the mold, resulting in increased mold volume and making it unsuitable for miniaturized two-color products. However, this application utilizes the mold space longitudinally through the design of reverse oblique guide holes and upper and lower oblique wedges, without occupying side space, thus expanding the application scenarios of the mold.

[0080] In this application, the end face of the common rear mold 32 is provided with a partial molding surface for forming hard plastic products. That is, when the first mold is closed, this partial molding surface of the common rear mold 32 is spliced ​​with the first rear mold to form a lower molding surface. In this embodiment, this partial molding surface is used to form the inclined side wall of the pressing plate, and it has a radial width and an axial depth. At the same time, this partial molding surface is used to support the hard plastic product after the first mold is separated. The end face of the common rear mold 32 serves as the main support surface for the hard plastic product. After the mold is separated, the hard plastic product is on this end face and is pressed to achieve overall movement and stable support. No manual or additional mechanism is required for transfer, which reduces the labor intensity of workers, improves the degree of automation, and avoids product positioning deviation caused by secondary placement, ensuring accurate coating of hard plastic and soft plastic, and improving product quality.

[0081] A pressing surface 312 facing the common rear mold 32 is provided at the end of the common slider 31. This pressing surface 312 is used to fit the top surface of the edge of the hard plastic product, specifically, to fit the top surface of the annular protrusion on the edge of the pressing plate. Through axial contact, the pressing surface is fixed, ensuring that the bottom surface of the hard plastic structure is always in contact with the common rear mold 32, thus improving the positional accuracy after transfer. The top surface of the annular protrusion is a non-appearance area. Later, during soft plastic injection molding, the top surface of the annular protrusion also serves as a covering surface. The pressing surface 312 only contacts this area, completely avoiding the appearance-sensitive area and achieving traceless pressing. Axial pressing not only avoids the appearance surface but also avoids deformation, damage, or positional displacement of the hard structure caused by radial pressing, ensuring the structural integrity and positioning accuracy of the hard plastic part during the transfer process, and effectively improving the stability and product yield of two-color injection molding.

[0082] In order to achieve a rapid response of the common slider during mold opening and closing and reduce its sliding formation, even if the common slider is close to the molding cavity, in this embodiment, the sidewalls of the first mold and the second mold at the mold closing position are provided with clearance grooves to avoid the common slider 31.

[0083] In this application, the mold closing direction of the first mold and the second mold is perpendicular to the horizontal plane, which makes the injection molded product after mold separation in a vertical state. Even if the rod of the hard plastic product is vertical, the pressing plate is located directly below the rod. This not only eliminates the horizontal parting line and ensures that the main body is free of parting line marks, thus improving the appearance of the product, but also facilitates the fixing of the pressing material and the transfer of its position.

[0084] The first mold and the second mold are arranged in parallel. The common module 3 is connected to a rotating mechanism, which can move between the first mold and the second mold. The rotation axis of the common module 3 is parallel to the mold closing and mold opening directions. In order to improve production efficiency, in this embodiment, there are two sets of common modules 3, which can move alternately between the first mold and the second mold. The common module 3 achieves a precise 180-degree rotation under the drive of the rotating mechanism, completing the switching between the two workstations and ensuring that the injection molding processes of hard plastic and soft plastic are carried out continuously and efficiently. During the rotation, the common module is accurately positioned and runs smoothly. With the high-speed response of the mold, the molding cycle is significantly shortened and the production efficiency is high.

[0085] To improve the motion accuracy of the common module, this application provides a first limiting part on the upper end and / or side wall of the common rear mold 32, and a second limiting part on the common slider 31. When the common slider 31 is in the pressing state, the second limiting part contacts the first part, thereby achieving limiting. This ensures the movement stroke of the common slider, avoids positioning deviation caused by overshoot, and ensures that the slider accurately fits the edge of the hard plastic product when the mold is closed, achieving stable pressing. To prevent the common module from shifting due to inertia or external force interference during movement, in this embodiment, a sliding damping is provided on the common slider 31, or the contact surface between the common slider 31 and the common rear mold 32 is a smooth surface, which can attract when the smooth surfaces are in contact. The sliding damping can absorb the impact energy during the wedge drive, avoid vibration or impact at the moment of contact with the slider, and at the same time, it can counteract the rebound tendency of the slider, ensuring that the slider has no displacement after pressing, and improving the pressing stability. By setting up smooth surfaces, when the two smooth surfaces come into contact, they can form a certain adsorption force, which prevents the slider from loosening or shifting due to vibration or inertia during the transfer of the common module, thus ensuring the stability of the pressing. When the wedge is inserted into the inclined hole of the common slider, it can overcome the adsorption force and drive the common slider to move. Its structure is simple and compact, and no other additional parts are required.

[0086] Meanwhile, the present invention also provides a method for working a two-color mold for a seamless product, which includes the following steps:

[0087] S1. Reset, the common module 3 moves to the first station and is located between the first front mold core 11 and the first rear mold core 12;

[0088] S2. In the first mold closing, the first front mold core 11 and the first rear mold core 12 move towards each other to achieve mold closing. After mold closing, the first rear mold core 12 is located in the mold hole 320 of the common rear mold 32, and a first molding cavity for hard plastic structure molding is formed between the first rear mold core 12, the common rear mold 32 and the first front mold core 11.

[0089] During the mold closing process, the first wedge 14 moves along the mold closing direction and inserts into the inclined guide hole of the common slider 31, pushing the common slider 31 to move outward, thereby avoiding collision and providing space for the mold closing of the first mold;

[0090] S3. In a single injection, the first injection molding machine injects hard plastic material into the first molding cavity to complete the injection molding of the hard plastic structure.

[0091] S4. First cooling: Cool and shape the hard plastic structure to ensure its structural stability and achieve demolding strength.

[0092] S5. In one mold opening, the first front mold core 11 and the first rear mold core 12 move along the mold opening direction to achieve mold separation. After mold separation, the first rear mold core 12 is located outside the mold hole 320 of the common rear mold 32, and the hard plastic structure remains on the common rear mold 32. Specifically, the inclined side wall of the pressing plate of the hard plastic structure contacts the molding surface on the common module to achieve support.

[0093] During the mold parting process, the first wedge 14 moves along the mold parting direction, causing the common slider 31 to move inward, and the pressing surface 312 at the end of the common slider 31 presses against the upper surface of the edge of the hard plastic structure, that is, the upper surface of the annular protrusion on the edge of the pressing plate, thereby fixing the hard plastic product.

[0094] Furthermore, after the mold parting is completed, the first wedge 14 disengages from the common slider 31, allowing the common module to separate from the first mold and not interfere with each other, thereby ensuring the smooth transfer of the position of the common module.

[0095] The common slider 31 can fit into the common rear mold under the action of damping or smooth surface adsorption, ensuring that no displacement occurs during the movement of the common module 3;

[0096] S6. Shifting: The driving mechanism drives the common module 3 to move the hard plastic product to the second station. In this embodiment, it is a rotary driving structure, so that the common module is located between the second front mold core 21 and the second rear mold core 22.

[0097] S7. Secondary mold closing: The second front mold core 21 and the second rear mold core 22 move towards each other to achieve mold closing. After mold closing, the second rear mold core 22 extends into the mold hole 320 of the common rear mold 32, and a second molding cavity for soft rubber structure molding is formed between the second rear mold core 22, the common rear mold 32 and the second front mold core 21.

[0098] During the mold closing process, the second wedge 24 moves along the mold closing direction and inserts into the inclined guide hole of the common slider 31, pushing the common slider 31 to move outward, releasing the pressure on the edge of the hard plastic product, and providing space for the second mold to close;

[0099] S8. Secondary injection: The second injection machine injects soft rubber material into the second molding cavity, so that it covers the surface of the hard rubber structure. Specifically, it covers the surface of the pressing plate. The through holes on the pressing plate are set to connect the soft rubber layers on the upper and lower surfaces on the one hand, and to allow the soft rubber to flow from one end to the other end. In this embodiment, it flows from the lower end to the upper end.

[0100] S9. Secondary cooling: Cooling and shaping the soft rubber product to ensure that the soft rubber and hard rubber are fully bonded and reach the demolding strength.

[0101] S10, Secondary mold opening: The second front mold core 21 and the second rear mold core 22 move in opposite directions to achieve mold separation. After mold separation, the second rear mold core 22 is located outside the mold hole 320 of the common rear mold 32, and the soft rubber covering the hard rubber product remains on the common rear mold 32.

[0102] During the mold parting process, the second wedge 24 moves along the parting direction and disengages from the common slider 31, so that the common module is separated from the second mold and does not interfere with each other, thereby ensuring the smooth transfer of the position of the common module.

[0103] S11. Unloading: The formed product is removed from the common rear mold 32 by a robotic arm or air nozzle.

[0104] S12, reset, the drive mechanism drives the common module 3 back to the first station, and repeats in sequence.

[0105] This application abandons the traditional mold design method and changes the product from the traditional horizontal placement to vertical placement, with all the glue parts of the main body protruding from the front mold. This avoids the parting line of horizontal placement and ensures that there are no parting line marks on the main body. Finally, the product is ejected by air blowing instead of traditional ejector pins, avoiding the appearance of ejector pin marks on the product.

[0106] After the first mold produces a hard plastic product, the mold is designed with a clearance structure to ensure two-color molding of different subsequent molds during the second mold's soft plastic molding. However, due to the clearance structure, the product may not be able to be fixed in place. To address this, the mold incorporates a glue-free slider structure. After the first mold is formed and opened, the glue-free slider presses down on the product under the action of the wedge, thus fixing the product. After rotating 180 degrees to the second mold, the glue-free slider detaches from the product under the action of the second mold's wedge, allowing for soft plastic injection in the second mold.

[0107] Since there is no adhesive on the slider throughout the entire process, and the slider only serves to fix the product, the slider will not produce parting lines on the product, thus achieving the requirement of a traceless product.

[0108] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A two-color die for a traceless product, characterized by, include: The first mold, set at the first station, is used for injection molding of hard plastic structures, and includes a first front mold core, a first rear mold core, and a first wedge. The second mold, set at the second station, is used for injection molding of soft rubber structures, including a second front mold core, a second rear mold core, and a second wedge. The common module, as a common end, can move between the first station and the second station, including a common rear mold and a common slider that slides on the outside of the common rear mold. The common rear mold has a mold hole for inserting the first rear mold core or the second rear mold core. When the first mold is being separated, the first wedge drives the common slider to clamp and fix the hard plastic product on the common rear mold; When the first mold and the second mold are closed, the first wedge or the second wedge drives the common slider to release and achieve avoidance.

2. The seamless product dual-color mold as described in claim 1, characterized in that: The first wedge can move along the mold closing and mold opening direction and move synchronously with the first front mold core or the first rear mold core. After the first mold is opened, the first wedge disengages from the common slider. The second wedge can move along the mold closing and mold opening direction and move synchronously with the second front mold core or the second rear mold core. After the second mold is opened, the second wedge disengages from the common slider.

3. The seamless product dual-color mold as described in claim 1, characterized in that: The common slider has oblique guide holes corresponding to the first and second oblique wedges. After the first and second oblique wedges are inserted into the oblique guide holes, they can drive the common slider to slide and achieve pressing and releasing.

4. The seamless product dual-color mold as described in claim 1, characterized in that: The end face of the common rear mold is provided with a partial molding surface for the hard plastic product and can support the hard plastic product after the first mold is separated.

5. The seamless product dual-color mold as described in claim 1, characterized in that: The end of the common slider is provided with a pressing surface facing the common rear mold and used to fit the top edge of the hard plastic product.

6. The seamless product dual-color mold as described in claim 1, characterized in that: The first mold and the second mold are perpendicular to the horizontal plane in the mold closing direction, so that the injection molded product after mold separation is in a vertical state; the first mold and the second mold are arranged in parallel, the common module is connected to a rotating mechanism and can move between the first mold and the second mold, and the rotation axis of the common module is parallel to the mold closing and mold separation direction.

7. The seamless product dual-color mold as described in claim 1, characterized in that: The common module consists of two sets and can move alternately between the first mold and the second mold.

8. The seamless product dual-color mold as described in claim 1, characterized in that: The common slider is provided with sliding damping, or the contact surface between the common slider and the common rear mold is a smooth surface and can be attracted when in contact.

9. A method of working with a seamless product dual-color mold as described in any one of claims 1-8, characterized in that, Includes the following steps: S1. Reset, the common module moves to the first station and is located between the first front mold core and the first rear mold core; S2. In the first mold closing, the first front mold core and the first rear mold core move towards each other to achieve mold closing. After mold closing, the first rear mold core is located in the mold hole of the common module, and a first molding cavity for hard plastic structure molding is formed between the first rear mold core, the common rear mold and the first front mold core. During the mold closing process, the first wedge moves along the mold closing direction and inserts into the inclined guide hole of the common slider, pushing the common slider to move outward, thereby avoiding collision and providing space for the first mold to close; S3. In a single injection, the first injection molding machine injects hard plastic material into the first molding cavity to complete the injection molding of the hard plastic structure. S4. First cooling: Cool and shape the hard plastic structure to ensure its structural stability and achieve demolding strength. S5. In one mold opening, the first front mold core and the first rear mold core move along the mold opening direction to achieve mold separation. After mold separation, the first rear mold core is located outside the mold hole of the common module, and the hard plastic structure remains on the common rear mold. During the mold parting process, the first wedge moves along the mold parting direction, causing the common slider to move inward and press the pressure surface at the end of the common slider against the upper edge of the hard plastic structure, thereby fixing the hard plastic product. Furthermore, after the mold parting is completed, the first wedge disengages from the common slider; S6, Shifting: The drive mechanism moves the common module, carrying the hard plastic product, to the second station and positions it between the second front mold core and the second rear mold core. S7. Secondary mold closing: The second front mold core and the second rear mold core move towards each other to achieve mold closing. After mold closing, the second rear mold core extends into the mold hole of the common rear mold, and a second molding cavity for molding soft rubber structure is formed between the second rear mold core, the common rear mold and the second front mold core. During the mold closing process, the second wedge moves along the mold closing direction and inserts into the inclined guide hole of the common slider, pushing the common slider to move outward, releasing the pressure on the edge of the hard plastic product, and providing space for the second mold to close; S8. Secondary injection: The second injection machine injects soft rubber material into the second molding cavity, so that it covers the surface of the hard rubber structure. S9. Secondary cooling: Cooling and shaping the soft rubber product to ensure that the soft rubber and hard rubber are fully bonded and reach the demolding strength. S10, Secondary mold opening: The second front mold core and the second rear mold core move in opposite directions to achieve mold separation. After mold separation, the second rear mold core is located outside the mold hole of the common rear mold, and the product with soft rubber covering hard rubber remains on the common rear mold. During the mold parting process, the second wedge moves along the mold parting direction and disengages from the common slider. S11. Unloading: The formed product is removed from the common rear mold by a robotic arm or air nozzle. S12, Reset, the drive mechanism drives the common module back to the first station.

10. A seamless two-color plastic part prepared using the working method described in claim 9, characterized in that: The device includes a hard rubber structure and a soft rubber structure. The hard rubber structure includes a rod and a circular pressing plate disposed at the lower end of the rod. The lower end surface of the pressing plate is an inwardly concave arc surface, and the side wall of the pressing plate is inclined, forming an inverted frustum structure with a larger upper end and a smaller lower end. The upper surface of the pressing plate is provided with an annular groove, and the edge of the upper surface of the pressing plate forms an annular protrusion. Multiple through holes penetrate between the annular groove and the arc surface. The soft rubber structure includes a first soft rubber layer disposed on the arc surface, a second soft rubber layer disposed in the annular groove, and a soft rubber column disposed in the through holes and connecting the first soft rubber layer and the second soft rubber layer.

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