Molding structure and manufacturing method of super-thin plastic chin for display

Abstract

This invention relates to the field of plastic injection molding technology, and discloses a molding structure and manufacturing method for an ultra-thin plastic chin part for displays. The structure includes a female mold core, a male mold core, a multi-point needle valve injection system, a hot runner-to-cold runner gate structure, a multi-stage venting structure, and a partitioned water channel system. The female mold core and male mold core are joined to form a long, narrow cavity. The multi-point needle valve injection system is arranged along the length of the cavity, and its outlet end connects to the hot runner-to-cold runner gate structure. The multi-stage venting structure is located at the parting surface of the long, narrow cavity, the mold slider area, and around the gate. By employing a combination of a ten-point needle valve array injection system and a hot runner-to-cold runner system, the melt flow range inside the long, narrow cavity is rationally divided, and the single-segment melt flow stroke is shortened. This satisfies the filling conditions of long, ultra-thin plastic parts and reduces the probability of filling defects and weld lines.

Description

Technical Field

[0001] This invention relates to the field of plastic injection molding technology, specifically to the molding structure and manufacturing method of an ultra-thin plastic chin part for a display screen. Background Technology

[0002] Currently, the elongated chin-like outer component at the bottom of monitors is generally made of metal. The metal manufacturing process is complex, resulting in high overall production costs. Furthermore, the finished product surface is prone to directional reflections, causing glare during daily use. To address these issues, the industry has begun using plastic to replace metal in the production of similar outer components. However, most existing plastic molding dies employ a single-point or few-point concentrated injection layout. When handling long, thin-walled elongated cavities, the melt flow distance is too long, leading to insufficient filling during the molding process, and noticeable weld lines easily form at the melt convergence points.

[0003] Existing mold venting layouts are relatively simple, relying solely on venting grooves on the parting surface to expel gas. The narrow and ultra-thin cavity has limited internal space, and the melt fills the mold quickly. Air trapped inside the cavity and trace amounts of gas generated by the melt heating cannot be expelled in time. Gas accumulation will cause molding defects on the surface of the plastic part, and at the same time, it will hinder the complete transfer of mold surface texture, making it impossible to stably form a uniform and consistent matte appearance. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a molding structure and manufacturing method for an ultra-thin plastic chin component for displays, solving the problem that existing molds cannot stably form a uniform matte finish.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a molding structure for an ultra-thin plastic chin part for a display, comprising a female mold core, a male mold core, a multi-point needle valve injection system, a hot runner-to-cold runner gate structure, a multi-stage venting structure, and a partitioned water channel system. The female mold core and the male mold core are molded together to form a long strip-shaped cavity. The multi-point needle valve injection system is arranged along the length of the long strip-shaped cavity. The discharge end of the multi-point needle valve injection system is connected to the hot runner-to-cold runner gate structure. The multi-stage venting structure is located at the parting surface of the long strip-shaped cavity, the mold slider area, and the periphery of the gate. The partitioned water channel system is arranged in partitions along the length of the long strip-shaped cavity.

[0006] By adopting the above technical solution—using an array-type hot runner system with ten needle valve injection points, combined with a hybrid structure design that converts hot and cold runners—the flow area of ​​the melt within the narrow cavity can be planned and defined, effectively shortening the actual path length of each melt flow segment. This allows it to fully meet the filling requirements of large-size, ultra-thin-walled plastic parts during injection molding, reducing incomplete filling defects caused by poor flow or insufficient pressure, and significantly reducing the possibility of weld lines. The side-mounted gates, through their guiding effect, prevent the melt from directly impacting the molded surface, thus better protecting the structural integrity and surface quality of the product's appearance.

[0007] Preferably, the multi-point needle valve glue injection system is a ten-point needle valve hot nozzle array structure, and each group of needle valve hot nozzles is equipped with an independent timing control component, so that each group of needle valve hot nozzles can independently realize the opening and closing timing control.

[0008] Preferably, the hot runner to cold runner gate structure includes a hot runner body and a side-mounted submerged cold runner gate. The hot runner body is connected to the discharge end of the needle valve hot nozzle, and the side-mounted cold runner gate is connected to the interior of the elongated cavity.

[0009] Preferably, the multi-stage exhaust structure includes a parting surface exhaust groove, a slider side exhaust groove, and a micro exhaust hole at the glue inlet. The three types of exhaust structures cooperate with each other to form a layered and orderly exhaust passage.

[0010] Preferably, the partitioned water system is divided into three independent cooling water channels along the length of the elongated cavity: a front cooling water channel, a middle cooling water channel, and a rear cooling water channel. Each of the three independent cooling water channels is connected to an independent mold temperature control device.

[0011] Preferably, it also includes a needle valve timing and zoned water circuit temperature control linkage control module, wherein the linkage control module is electrically connected to the multi-point needle valve injection system and the zoned water circuit system respectively, so as to synchronously adjust the mold temperature of the corresponding area according to the needle valve filling sequence.

[0012] Preferably, the surface of the master mold core is provided with a textured venting and air guiding structure, the matte textured surface is set at the corresponding position of the venting structure, the textured air guiding groove is arranged in a gradient form, and the textured air guiding groove is connected to the internal air guiding channel of the multi-stage venting structure.

[0013] Preferably, a method for manufacturing an ultra-thin plastic chin component for a display includes the following steps: S1. The mold is closed to form a long strip-shaped molding cavity; S2. Melt the PC / ABS raw materials to obtain a homogeneous melt adhesive; S3. Molten glue is injected into the elongated cavity through a multi-point needle valve glue injection system in conjunction with a hot runner to cold runner gate structure. S4. During the melt filling process, the multi-stage venting structure is activated to expel the gas trapped inside the long strip cavity. S5. Implement zoned mold temperature control through a zoned water system, and use the molding surface of the master mold core to replicate the matte texture; S6. After the plastic part has cooled and solidified sufficiently, the ejection operation is carried out to obtain the finished ultra-thin plastic chin part.

[0014] Preferably, in step S5, the melting molding progress and the zoned cooling rhythm are matched by the linkage control module, and the textured exhaust adapter air guide structure is used to assist in the discharge of residual gas in the long strip cavity.

[0015] Preferably, the chin piece is installed on the lower edge of the display. The chin piece has a long, integrated structure with a length of 450mm-850mm and a maximum thickness of no more than 0.5mm. The chin piece is made of PC / ABS material and is integrally injection molded. The outer surface of the chin piece has a matte textured finish.

[0016] This invention provides a molding structure and manufacturing method for an ultra-thin plastic chin component for displays. It offers the following advantages: 1. This invention adopts a combination structure of ten-point needle valve array injection and hot runner to cold runner, which reasonably divides the melt flow range inside the long cavity, shortens the single melt flow stroke, can meet the mold filling conditions of long and thin plastic parts, reduce the probability of filling defects and weld lines, and the side gate flow guiding method can also protect the integrity of the appearance molding surface structure.

[0017] 2. This invention combines a multi-stage venting structure with a textured venting adaptation structure, which can orderly discharge various types of stagnant gases inside the cavity during the molding process. With the help of textured grooves on the surface of the mold core to guide the gas, the interference of gas on texture transfer is eliminated, and a stable and uniform matte structure is formed. This structure also weakens the surface reflection of the product.

[0018] 3. This invention relies on a partitioned water circuit combined with a timed temperature control linkage module to regulate the mold temperature. It can adjust the cooling state of each area according to the melt filling progress, balance the shrinkage of long plastic parts, suppress product molding deformation, ensure the uniformity of product size and appearance in mass production, and is compatible with conventional injection molding production lines for mass processing. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the integral molding mold of the present invention in the mold-closed state; Figure 2 This is a top view of the hot runner arrangement structure of the present invention; Figure 3 This is a top view of the male mold core of the present invention; Figure 4 This is a top view of the female mold core of the present invention; Figure 5 This is a schematic diagram of the overall external structure of the finished product of the present invention; Figure 6 This is a flowchart of the present invention.

[0020] The components include: 1. Female mold core; 2. Male mold core; 3. Long strip cavity; 4. Needle valve hot nozzle; 5. Hot runner body; 6. Side-mounted submerged cold runner gate; 7. Multi-stage venting structure; 8. Textured air guide groove. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Please see the appendix Figure 1 - Appendix Figure 5This invention provides a molding structure for an ultra-thin plastic chin part for a display screen, comprising a female mold core 1, a male mold core 2, a multi-point needle valve injection system, a hot runner-to-cold runner gate structure, a multi-stage venting structure 7, and a partitioned water channel system. The female mold core 1 and the male mold core 2 are molded together to form a long strip-shaped cavity 3. The multi-point needle valve injection system is arranged along the length of the long strip-shaped cavity 3. The discharge end of the multi-point needle valve injection system is connected to the hot runner-to-cold runner gate structure. The multi-stage venting structure... 7 is located at the parting surface of the elongated cavity 3, the mold slider area, and around the gate. The partitioned water channel system is arranged in sections along the length of the elongated cavity 3. The multi-point needle valve injection system is an array structure of ten needle valve hot nozzles 4. Each group of needle valve hot nozzles 4 is equipped with an independent timing control component, and each group of needle valve hot nozzles 4 can independently realize the opening and closing timing control. The hot runner to cold runner gate structure includes the hot runner body 5 and the side-mounted cold runner gate 6. The hot runner body 5 and the needle valve The hot nozzle 4 is connected to the discharge end, and the side-mounted submerged cold runner gate 6 is connected to the interior of the elongated cavity 3. The multi-stage venting structure 7 includes a parting surface venting groove, a slider side venting groove, and a micro venting hole at the injection port. The three types of venting structures work together to form a layered and orderly venting passage. The partitioned water system is divided into three independent cooling water channels along the length of the elongated cavity 3: a front cooling water channel, a middle cooling water channel, and a rear cooling water channel. The three independent cooling water channels are connected to independent mold temperature control devices. It also includes a needle valve timing and partitioned water channel temperature control linkage control module. The linkage control module is electrically connected to the multi-point needle valve injection system and the partitioned water channel system to synchronously control the mold temperature of the corresponding area according to the needle valve filling sequence. The surface of the mother mold core 1 is provided with a textured venting and air guiding structure. The matte texture is set at the corresponding position of the venting structure and adopts a gradient layout. The textured air guiding groove 8 is connected to the air guiding channel inside the multi-stage venting structure 7.

[0023] Specifically, the molding structure mainly consists of a female mold core 1 and a male mold core 2, forming the basic molding body. Both the female mold core 1 and the male mold core 2 are processed according to the general machining precision of appearance injection molds. The inner molding surface of the female mold core 1 is hardened to ensure the stability of long-term texture transfer use, while the inner molding surface of the male mold core 2 is smoothed. The female mold core 1 and the male mold core 2 are precisely aligned by the internal positioning components of the mold. After the mold is closed and locked, they form a closed elongated cavity 3. The thickness of the cavity 3 is consistent with the thickness of the finished chin part. The two ends of the cavity are sealed to prevent the molten material from overflowing. Ten sets of needle valve hot nozzles 4 are evenly and equidistantly arranged along the overall length of the elongated cavity 3. All needle valve hot nozzles 4 are made of the same specification of general hot runner needle valve components, and the arrangement of all needle valve hot nozzles 4 is parallel to the length of the cavity. Each set of needle valve hot nozzles 4 is individually equipped with a timing control component, which is fixedly installed in the electrical control area on the fixed mold side of the mold. Each set of timing control components operates independently, and the opening and closing times of a single set of needle valve hot nozzles 4 can be set individually according to the actual filling progress inside the cavity. Multiple sets of needle valves can also be set to operate synchronously. The discharge end of each set of needle valve hot nozzles 4 is connected to the hot runner body 5. A constant temperature heating component is installed on the outside of the hot runner body 5 to continuously maintain the internal material in a molten flow state during operation, preventing premature solidification and blockage of the channel. The discharge position of the hot runner body 5 connects to the side-mounted submerged cold runner gate 6, which is arranged along the lateral tangential direction of the cavity. The internal flow cross-section of the gate is smaller than that of the front-end hot runner.

[0024] Please see the appendix Figure 1 - Appendix Figure 6 S1. The mold is closed to form a long, narrow cavity 3; S2. PC / ABS raw materials are melted to obtain homogeneous molten plastic; S3. Molten plastic is injected into the long, narrow cavity 3 through a multi-point needle valve injection system in conjunction with a hot runner-to-cold runner gate structure; S4. During the molten plastic filling process, the multi-stage venting structure 7 is activated to expel the gas trapped inside the long, narrow cavity 3; S5. The mold temperature is controlled by a zoned water channel system, and a matte textured pattern is formed by replicating the molding surface of the female mold core 1; S6. After the plastic part has fully cooled and solidified, the ejection operation is performed to obtain the finished ultra-thin plastic product. The finished chin part is designed for appearance. In the S5, the melting and filling progress and the cooling rhythm of the partition are matched through the linkage control module. At the same time, the textured venting and air guiding structure is used to help discharge the residual gas in the long strip cavity 3. The finished chin part is installed at the lower edge of the display. The finished chin part has a long strip integrated structure. The length of the finished chin part is set to 450mm-850mm. The maximum thickness of the finished chin part is no more than 0.5mm. The finished chin part is made of PC / ABS material and is injection molded in one piece. The outer appearance surface of the finished chin part is integrally molded with a matte textured finish.

[0025] Specifically, before officially commencing injection molding, the final verification of all components of the entire mold is completed. Impurities and dust remaining inside the elongated cavity 3, various runners, and the venting structure are cleaned, and all electrical and temperature control components are confirmed to be functioning correctly. The PC and ABS plastic raw materials are dried and dehumidified in advance to remove free moisture. After this process, the raw materials are fed into the injection molding machine barrel and plasticized according to standard thin-walled plastic part melting procedures to obtain a uniform molten material. The mold is then locked, ensuring the female mold core 1 and male mold core 2 fit tightly together to form a complete elongated cavity 3. The needle valve hot nozzles 4 are activated according to a pre-set opening and closing sequence, and the molten material flows smoothly into the cavity through the hot runner body 5 and the side-mounted submerged cold runner gate 6. Throughout the melt filling process, the parting surface venting groove, the slider side venting groove, and the micro-venting holes at the injection port simultaneously expel gas. While the melt filling operation is underway, the linkage control module is activated to synchronously adjust the operating temperature of the cooling water channels in each area according to the actual filling progress. The surface molding structure of the mold core 1 is used to complete the integrated molding of the plastic part's appearance and texture. After the melt is completely filled into the elongated cavity 3, the pressure holding and constant temperature shaping operations are completed according to the industry-standard cooling time. After confirming that the plastic part has fully solidified and shaped, the mold ejection mechanism is smoothly activated, and the finished product is smoothly ejected from the cavity using a uniform force. After the finished product is removed, a simple appearance and basic dimension verification is performed before proceeding to the next molding cycle to continuously complete the batch production of products.

[0026] Working Principle: After the mold is fully assembled, the multi-point needle valve injection system, multi-stage venting structure 7, zoned water system, and linkage control module are sequentially aligned and installed. All external control devices and pipelines are neatly arranged and debugged before entering the molding and use state. The needle valve hot nozzle 4 is fixedly installed in the fixed mold position and does not follow the moving mold to open and close during operation. The discharge end of the needle valve hot nozzle 4 is seamlessly connected to the rear flow channel structure, preventing material stagnation and overflow during material transportation. By using a grouped and timed feeding method, the melt flow path inside the long strip cavity is split, shortening the single-segment melt flow distance and improving the problems of poor melt filling and obvious melt junction marks inside long and ultra-thin cavities. The molten material is first conveyed under stable pressure and temperature through the hot runner body 5, and then the flow speed is buffered through the side-mounted submerged cold runner gate 6, flowing smoothly into the long strip cavity 3. This avoids the high-speed flowing melt directly impacting the molded surface of the cavity, while also reducing molding marks at the gate position and ensuring the overall integrity of the plastic part's appearance.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art 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 appended claims and their equivalents.

Claims

1. A molding structure for an ultra-thin plastic chin part for a display, comprising a female mold core (1), a male mold core (2), a multi-point needle valve injection system, a hot runner to cold runner gate structure, a multi-stage venting structure (7), and a partitioned water channel system, characterized in that: The female mold core (1) and the male mold core (2) are molded together to form a long strip cavity (3). The multi-point needle valve injection system is arranged along the length of the long strip cavity (3). The discharge end of the multi-point needle valve injection system is connected to the hot runner to cold runner gate structure. The multi-stage venting structure (7) is set on the parting surface of the long strip cavity (3), the mold slider area and the gate periphery. The partitioned water channel system is arranged in partitions along the length of the long strip cavity (3).

2. The molding structure of the ultra-thin plastic chin component for a display according to claim 1, characterized in that: The multi-point needle valve glue injection system is a ten-point needle valve hot nozzle (4) array arrangement structure. Each group of needle valve hot nozzles (4) is equipped with an independent timing control component, and each group of needle valve hot nozzles (4) can independently realize the opening and closing timing control.

3. The molding structure of the ultra-thin plastic chin component for a display according to claim 1, characterized in that: The hot runner to cold runner gate structure includes a hot runner body (5) and a side-mounted submerged cold runner gate (6). The hot runner body (5) is connected to the discharge end of the needle valve hot nozzle (4), and the side-mounted submerged cold runner gate (6) is connected to the interior of the elongated cavity (3).

4. The molding structure of the ultra-thin plastic chin component for a display according to claim 1, characterized in that: The multi-stage exhaust structure (7) includes a parting surface exhaust groove, a slider side exhaust groove, and a micro exhaust hole at the glue inlet. The three types of exhaust structures cooperate with each other to form a layered and orderly exhaust passage.

5. The molding structure of the ultra-thin plastic chin component for a display according to claim 1, characterized in that: The partitioned water system is divided into three independent cooling water channels along the length of the elongated cavity (3): front cooling water channel, middle cooling water channel, and rear cooling water channel. Each of the three independent cooling water channels is connected to an independent mold temperature control device.

6. The molding structure of the ultra-thin plastic chin component for a display according to claim 1, characterized in that: It also includes a needle valve timing and zoned water circuit temperature control linkage control module. The linkage control module is electrically connected to the multi-point needle valve injection system and the zoned water circuit system respectively, so as to synchronously adjust the mold temperature of the corresponding area according to the needle valve filling sequence.

7. The molding structure of the ultra-thin plastic chin component for a display according to claim 1, characterized in that: The surface of the master mold core (1) is provided with a textured venting and air guiding structure. The matte textured pattern is set at the corresponding position of the venting structure and is arranged in a gradient manner. The textured air guiding groove (8) is connected to the air guiding channel inside the multi-stage venting structure (7).

8. A method for manufacturing an ultra-thin plastic chin component for a display, comprising the molding structure of the ultra-thin plastic chin component for a display according to any one of claims 1-7, characterized in that, Includes the following steps: S1. The mold is closed to form a long strip cavity (3); S2. The PC / ABS raw material is melted to obtain homogeneous melt; S3. Melt is injected into the long strip cavity (3) through a multi-point needle valve injection system in conjunction with a hot runner to cold runner gate structure; S4. During the melt filling process, the multi-stage venting structure (7) is opened to discharge the gas trapped inside the long strip cavity (3); S5. The partitioned mold temperature is controlled by the partitioned water system, and the matte texture is formed by replicating the molding surface with the help of the mother mold core (1); S6. After the plastic part has cooled and solidified, the ejection operation is carried out to obtain the finished ultra-thin plastic chin part.

9. The method for manufacturing an ultra-thin plastic chin component for a display according to claim 8, characterized in that: In S5, the melting molding progress and the partition cooling rhythm are matched by the linkage control module, and the residual gas in the long strip cavity (3) is assisted by the textured exhaust adapter gas guiding structure.

10. The method for manufacturing an ultra-thin plastic chin component for a display according to claim 8, characterized in that: The finished chin piece is installed on the lower edge of the display. The finished chin piece has a long, one-piece structure with a length of 450mm-850mm. The maximum thickness of the chin piece is no more than 0.5mm. The finished chin piece is made of PC / ABS material and is injection molded in one piece. The outer surface of the finished chin piece has a matte textured finish.

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