A forming mold and injection molding method for a thin elongated chin piece

Abstract

The application provides a forming die and an injection molding method for a thin long chin piece. The die comprises: a first die assembly; a second die assembly, which can be matched with the first die assembly to form a cavity; a multi-point needle valve feeding system arranged on the first die assembly, the multi-point needle valve feeding system comprising a hot runner, a needle valve and a cold runner which are sequentially communicated; the cold runner is communicated with the cavity through a gate; the gate is flat, and the gate is gradually expanded in the direction close to the cavity; an exhaust groove group is further arranged on the die, and the exhaust groove group is arranged in one or any multiple of a parting surface, a flow end, a slider area or a molten glue intersection area. The application reduces the control difficulty of chin piece injection molding and improves the stability and flexibility of chin piece presentation effect preparation.

Description

Technical Field

[0001] This application relates to the field of mold technology, and in particular to a molding die and injection molding method for a thin, elongated chin part. Background Technology

[0002] Injection molds are specialized molding tools used in the injection molding process to manufacture corresponding products.

[0003] Existing display chin components are typically long and thin, with a length of 450-750mm and a thickness of no more than 0.5mm. These display chin components are formed by injection molding, which is difficult to control and cannot meet actual needs. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the technical solution adopted in this application is to propose a molding die for a thin, elongated chin piece.

[0005] The first aspect of this application provides a molding die for a thin, elongated chin piece, used in the fabrication process of the thin, elongated chin piece, the die comprising:

[0006] First mold assembly; The second mold assembly can cooperate with the first mold assembly to form a plurality of thin, elongated cavities; A multi-point needle valve feeding system is installed on the first mold assembly. The multi-point needle valve feeding system includes a hot runner, a needle valve, and a cold runner connected in sequence. Several cold runners are distributed along the extension direction of the cavity and are respectively connected to the cavity so that each cold runner corresponds to a different area of ​​the cavity. The hot runner is connected to the cold runner through a needle valve. The multi-point needle valve feeding system is used to control the opening and closing sequence, opening and closing time and opening and closing degree of different needle valves during the injection molding process so that different areas on the chin part present a consistent injection molding effect. The cold runner is connected to the cavity through a gate, which is flat and gradually expands in the direction close to the cavity; The mold is also provided with a group of venting grooves, which are located in one or more of the parting surface, the flow end, the slider area, or the melt confluence area.

[0007] In an optional embodiment, the first mold assembly includes a first template and a first mold core, and the second mold assembly includes a second template, a second mold core, and a sliding member; The first mold assembly is used to fit with the second mold assembly to form at least two cavities between the first mold core, the second mold core and the sliding member; The multi-point needle valve feeding system is connected to the at least two cavities respectively, so that the chin parts located in different cavities present a consistent injection molding effect.

[0008] In an optional embodiment, the venting groove group includes a first venting groove and a second venting groove, wherein the first venting groove is connected to the cavity and the second venting groove respectively; The depth of the first exhaust groove is not greater than the depth of the second exhaust groove.

[0009] In an optional embodiment, the venting groove group is provided between the first mold core and the second mold core, distributed along the cavity spacing; A plurality of venting groove groups are provided between the sliding member and the first mold core and / or the second mold core. All the first venting grooves are continuously arranged along the length direction of the cavity. Each second venting groove is connected to the first venting groove and is arranged at intervals corresponding to the first venting groove.

[0010] In an optional embodiment, a zoned cooling system is also provided; The partitioned cooling system includes a first cooling module, a second cooling module, and a third cooling module; The first cooling module is disposed at least through the first mold core, the second cooling module is disposed at least through the second mold core, and the third cooling module is disposed at least through the sliding member; The first mold assembly is used to fit the second mold assembly so that the multi-point needle valve feeding system and the cavity are located in the area formed by the partitioned cooling system.

[0011] In an optional embodiment, the first cooling module includes a first cavity cooling water channel and a first feed cooling water channel. The first cavity cooling water channel extends along the length direction of the cavity, and the first feed cooling water channel is spaced apart along the length direction of the first cavity cooling water channel so as to be staggered with the first cavity cooling water channel. The second cooling module includes a second cavity cooling water channel and a second feed cooling water channel. The extension direction of the second cavity cooling water channel is the same as that of the second feed cooling water channel. The second cavity cooling water channel and the second feed cooling water channel are arranged along the plastic flow direction, so as to be staggered with the first feed cooling water channel. The third cooling module includes a slider cooling water channel, which is arranged along the sliding direction of the slider and located between the first cavity cooling water channel and the second cavity cooling water channel. The first mold assembly is used to fit the second mold assembly so that the partitioned cooling system cools the multi-point needle valve feeding system and the cavity from at least two directions.

[0012] In an optional embodiment, each of the cold runners is provided with sub-runners of progressively decreasing flow rates from near to far, and the end sub-runner is connected to the cavity through the gate; A cooling section is provided at the connection point of each sub-channel. The cooling section extends along the extension direction of the previous sub-channel so that the plastic flows through the cooling section at least partially due to inertia, and then flows to each of the next sub-channels, so that the temperature and fluidity of the plastic entering the cavity meet the preset target.

[0013] A second aspect of this application provides an injection molding method, wherein injection molding is performed using an injection mold as described in any one of the first aspects, the method comprising: Obtain the required injection molding effect and generate injection signals; Based on the injection signal, control the opening and closing sequence, opening and closing time and opening and closing degree of different needle valves in the multi-point needle valve feeding system; The molten plastic material is injected into the mold cavity through a multi-point needle valve feeding system; And the gas in the cavity is passively removed in stages through the venting grooves set on the injection mold; Furthermore, based on the injection signal, the cooling temperature, cooling time, and cooling sequence of different cooling modules in the partitioned cooling system set on the injection mold are controlled to complete the injection molding of the chin part.

[0014] This application has at least the following beneficial effects: This application provides a molding die and injection molding method for a thin, elongated chin piece, which reduces the control difficulty of injection molding of the chin piece, improves the stability and flexibility of the chin piece presentation effect preparation, and effectively meets the actual needs of the chin piece. Specifically, the mold includes a multi-point needle valve feeding system, which comprises a hot runner, a cold runner, and needle valves connected in sequence. Several cold runners are connected to the cavity. On the one hand, this system enables control of different areas within the cavity, effectively reducing the difficulty of injection molding control. On the other hand, it shortens the flow length of a single injection path, effectively reducing short shots and excessive pressure, and improving the aesthetics and molding stability of the chin part. Furthermore, by controlling the opening and closing sequence, opening and closing time, and opening and closing degree of different needle valves, the system ensures that different areas on the chin part exhibit a consistent injection molding effect, thereby meeting the actual appearance requirements of the chin part. The cold runner connects to the mold cavity through a flat gate, which effectively improves the expansion of the plastic melt, reduces flow resistance and mold filling pressure, improves the fluidity of the plastic in the mold cavity, and reduces the generation of cold material marks to a certain extent. The molding die for the thin, elongated chin part is also equipped with an air venting system, which effectively solves the problem of gas retention during the injection molding process and largely avoids problems such as scorching, insufficient filling, flash, and black shadow caused by trapped air. By optimizing the fabrication process of thin, elongated chin parts such as chin components through the multi-point needle valve feeding system, the structural design of the cold runner, the sectional venting of the venting slot group, and the coordinated operation of the side fan-shaped gate, the molding quality of the products has been improved. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A three-dimensional structural diagram of a molding die for a thin, elongated chin piece according to one embodiment; Figure 2 A cross-sectional structural schematic diagram of the molding die for a thin, elongated chin piece according to one embodiment; Figure 3 This is a schematic diagram of the structure of a first mold assembly according to one embodiment; Figure 4 This is a schematic diagram of the structure of the second mold assembly in one embodiment; Figure 5 This is a schematic diagram illustrating the connection state between a multi-point needle valve feeding system and the mold cavity in one embodiment. Figure 6 For one Figure 5 Enlarged detail view of point A in the middle; Figure 7 Schematic diagram of the location of the exhaust channel assembly in one embodiment Figure 1 ; Figure 8 Schematic diagram of the location of the exhaust channel assembly in one embodiment Figure 2 ; Figure 9 A schematic diagram of a partitioned cooling system layout for one embodiment. Figure 1 ; Figure 10 A schematic diagram of a partitioned cooling system layout for one embodiment. Figure 2 ; Figure 11 This is a flowchart of an injection molding method according to one embodiment.

[0017] Figure label: 1-First mold assembly; 11-First template; 12-First mold core; 2-Second mold assembly; 21-Second template; 22-Second mold core; 23-Sliding component; 3-Cavity; 4-Multi-point needle valve feeding system; 41-Hot runner; 42-Needle valve; 43-Cold runner; 431-Sub-runner; 432-Cooling section; 44-Gate; 5-Ventilation channel assembly; 51-First ventilation channel; 52-Second ventilation channel; 61-First cooling module; 611-First cavity cooling water channel; 612-First feeding cooling water channel; 62-Second cooling module; 621-Second cavity cooling water channel; 622-Second feeding cooling water channel; 63-Third cooling module; 631-Slider cooling water channel. Detailed Implementation

[0018] Various embodiments of this disclosure will be described more fully below. This disclosure may have various embodiments, and adjustments and changes may be made therein. However, it should be understood that there is no intention to limit the various embodiments of this disclosure to the specific embodiments disclosed herein, but rather this disclosure should be understood to cover all adjustments, equivalents, and / or alternatives falling within the spirit and scope of the various embodiments of this disclosure.

[0019] In the following, the terms “comprising” or “may include”, which may be used in various embodiments of this disclosure, indicate the presence of the disclosed functions, operations, or elements, and do not limit the addition of one or more functions, operations, or elements. Furthermore, as used in various embodiments of this disclosure, the terms “comprising,” “having,” and their cognates are intended only to indicate a particular feature, number, step, operation, element, component, or combination of the foregoing, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations of the foregoing, or the possibility of adding one or more combinations of the foregoing.

[0020] In various embodiments of this disclosure, the expression "or" or "at least one of A and / or B" includes any combination or all combinations of the words listed simultaneously. For example, the expression "A or B" or "at least one of A and / or B" may include A, may include B, or may include both A and B.

[0021] The terms used in the various embodiments of this disclosure (such as "first," "second," etc.) may modify various components in the various embodiments, but do not limit the corresponding components. For example, the above terms do not limit the order and / or importance of the components. The above terms are only used for the purpose of distinguishing one component from others. For example, a first user device and a second user device refer to different user devices, although both are user devices. For example, a first component may be referred to as a second component without departing from the scope of the various embodiments of this disclosure, and similarly, a second component may also be referred to as a first component.

[0022] It should be noted that if a description is made of "connecting" one component to another, then the first component can be directly connected to the second component, and a third component can be "connected" between the first and second components. Conversely, when a component is "directly connected" to another component, it can be understood that there is no third component between the first and second components.

[0023] The term "user" as used in various embodiments of this disclosure may refer to a person using an electronic device or a device using an electronic device (e.g., an artificial intelligence electronic device).

[0024] The terminology used in the various embodiments of this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the various embodiments of this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this disclosure pertain. Terms (such as those defined in a generally used dictionary) are to be interpreted as having the same meaning as in the context of the relevant technical field and are not to be interpreted as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this disclosure.

[0025] A display chin is a long, strip-shaped plastic component located on the lower edge of the display panel. It forms the lower boundary of the display, improves the visual effect of the screen, and reduces glare. The length of the chin is generally 450mm to 750mm, and the maximum thickness does not exceed 0.5mm.

[0026] See Figures 1 to 6 As shown, this application provides a molding die for a thin, elongated chin piece, used in the manufacturing process of the thin, elongated chin piece, including: a first mold assembly 1, a second mold assembly 2, and a multi-point needle valve feeding system 4; The second mold assembly 2 can cooperate with the first mold assembly 1 to form several thin, elongated cavities 3; In this embodiment, the first mold assembly 1 and the second mold assembly 2 are adapted to each other and press against each other to achieve mold closing. The second mold assembly 2 can be fixedly set, and the opening and closing of the mold is achieved by the action of the first mold assembly 1. After the first mold assembly 1 and the second mold assembly 2 are closed, a cavity 3 for injection molding into a chin part is formed between the first mold assembly 1 and the second mold assembly 2. The number of cavities 3 can be one, two, three or more.

[0027] A multi-point needle valve feeding system 4 is installed on the first mold assembly 1. The multi-point needle valve feeding system 4 includes a hot runner 41, a needle valve 42 and a cold runner 43 connected in sequence. Several cold runners 43 are distributed along the extension direction of the cavity 3 and are connected to the cavity 3 respectively, so that each cold runner 43 corresponds to a different area of ​​the cavity 3. The hot runner 41 and the cold runner 43 are connected by needle valves 42. The multi-point needle valve feeding system 4 is used to control the opening and closing sequence, opening and closing time and opening and closing degree of different needle valves 42 during the injection molding process, so that different areas on the chin part present a consistent injection molding effect.

[0028] Specifically, in some embodiments of this application, 10 pairs of cold runners 43 are provided, and 10 needle valves 42 are provided corresponding to the number of cold runners 43; of course, no specific limitation is made on the number of cold runners 43 and the number of needle valves 42.

[0029] The hot runner 41 refers to the channel through which plastic enters the mold from the injection nozzle and is distributed to the needle valves 42. The hot runner 41 and the cold runner 43 are connected by the needle valves 42. The valve needles can be driven by hydraulic cylinders, pneumatic cylinders, or servo motors to open and close the cold runner 43. When the valve needle moves in the first direction, the cold runner 43 opens, and the molten plastic can pass through. When the valve needle moves in the second direction opposite to the first direction, the cold runner 43 closes. The cold runner 43 is the channel connecting the hot runner 41 and the cavity 3. Compared to the main runner, which has a lower temperature, the hot runner 41 is usually heated or kept warm, while the cold runner 43 is usually not heated or has a very weak heating effect.

[0030] Understandably, by arranging several independent cold runners 43 along the extension direction of the cavity 3, precise material feeding to different areas of the cavity 3 is achieved. Combined with the needle valve 42 control structure between the hot runner 41 and the cold runner 43, and utilizing the timing and opening adjustment function of the multi-point needle valve feeding system 4 during the injection molding process, the melt filling behavior can be dynamically adjusted according to the required shape differences of different areas of the product. This can effectively solve problems such as air trapping, weld lines, and uneven shrinkage caused by traditional single-point injection, significantly improving the surface flatness and appearance consistency of the chin part. At the same time, by differentiating the opening and closing sequence, time, and opening degree of each needle valve 42, the melting point can be controlled, reducing interference and marks before melting flow. This allows for flexible achievement of differentiated textures, gloss, or physical properties in different areas of the same chin part, greatly enhancing the compatibility of the injection molding process and the added value of the product.

[0031] Furthermore, by setting up independent cold runners 43, independent melt delivery channels for different areas of cavity 3 are established, eliminating the problem of uneven pressure and temperature changes caused by long-flow filling. When the injection of cavity 3 is completed synchronously through each independent cold runner 43, it helps to achieve a consistent injection molding effect, reduces short-shot defects, and improves the molding quality of the chin part.

[0032] The chin piece can be injection molded from ABS material alone, or it can be injection molded from PC+ABS material. The general engineering material concept of PC+ABS is PC / ABS blend, which is a blended material.

[0033] like Figure 6 As shown, in an optional embodiment, the cooling channel 43 is connected to the cavity 3 via the gate 44; The gate 44 is flat and gradually expands along the direction close to the cavity 3.

[0034] Specifically, in some embodiments of this application, the width of the gate 44 is approximately 6 mm, and the residual plastic on the corresponding portion of the gate 44 after trimming is less than 0.3 mm, not exceeding the outer surface of the chin part. Of course, there is no limitation on the specific size of the gate 44.

[0035] Understandably, the flat shape of the gate 44, which gradually widens towards the cavity 3, can increase the expansion effect of the plastic melt, which helps the plastic diffuse within the cavity 3 to a certain extent, thereby reducing flow resistance and mold filling pressure, improving the fluidity of the plastic within the cavity 3, and reducing the generation of cold slug marks to a certain extent. The flat gate 44 also helps to reduce the residual stress after the plastic passes through, reduce warping deformation caused by uneven molecular orientation, and facilitate subsequent trimming, thus improving the aesthetics of the gate 44 marks.

[0036] In addition, the gate 44 is connected to the side wall of the cavity 3, which allows the joint line to avoid the main visually sensitive area, reducing visible defects and further improving the aesthetics of the chin part.

[0037] Combination Figures 1 to 4 As shown, in an optional embodiment, the first mold assembly 1 includes a first template 11 and a first mold core 12, and the second mold assembly 2 includes a second template 21, a second mold core 22 and a slider 23; The first mold assembly 1 is used to fit with the second mold assembly 2 to form at least two cavities 3 between the first mold core 12, the second mold core 22 and the sliding member 23; The multi-point needle valve feeding system 4 is connected to at least two cavities 3 respectively, so that the chin parts located in different cavities 3 present a consistent injection molding effect.

[0038] Specifically, in some embodiments of this application, the cold runner 43 includes a first cold runner 43 and a second cold runner 43 symmetrically arranged with the needle valve 42 as the center line, and the first cold runner 43 and the second cold runner 43 are respectively connected to different cavities 3.

[0039] More specifically, in some embodiments of this application, the slider 23 may be referred to as a slider for lateral core pulling or forming product side holes / recesses.

[0040] Understandably, this application constructs a stable mold-closing structure through the precise cooperation of the first template 11, the first mold core 12, the second template 21, the second mold core 22, and the sliding component 23. The multi-point needle valve feeding system 4 connects to at least two cavities 3 respectively, so that the plastic flow effect, flow speed, flow rate, and pressure transmission in the corresponding cavities 3 are consistent. This ensures that the chin parts located in different cavities 3 maintain stability in density, dimensional accuracy, and surface texture, thereby making the same set of chin parts more consistent in visual effect and physical and mechanical properties. This reduces the difference between chin parts in batches, optimizes the decorative effect of chin parts, and allows multiple chin parts to be produced by injection molding, shortening the overall preparation time of multiple chin parts and effectively improving the preparation efficiency of chin parts.

[0041] Combination Figure 7 and Figure 8 As shown, in an optional embodiment, the molding die for the thin, elongated chin piece is further provided with an exhaust groove group 5; The venting groove group 5 is set in one or more of the parting surface, flow end, slider area or melt confluence area.

[0042] Among them, the parting surface, flow end, slider area and sol confluence area are important areas for the molding of the chin part. The venting groove group 5 is arranged for these areas to specifically solve the problem of gas retention in the chin part during the injection molding process, and to a large extent avoids the problems of burning, insufficient filling, flash and black shadow caused by trapped gas.

[0043] For example, by setting an venting groove group 5 at the flow end and the junction of the molten plastic, the flow end refers to the area where the plastic lasts to arrive. This can effectively guide the air in the cavity 3 to be fully discharged, reducing the problems of scorching, insufficient filling and burrs caused by trapped air. It can also promote the plastic melt to fuse more easily, reduce weld lines or weld lines, and reduce the influence of black shadows. For example, by setting an venting groove group 5 at the parting surface, the occurrence of trapped air can be reduced. Furthermore, by setting an venting groove group 5 in the slider area, the venting function and burr control function can be combined, which helps to balance the air pressure in the cavity 3 and improve the surface density and dimensional accuracy of the chin part.

[0044] In an optional embodiment, such as Figure 7 and Figure 8 As shown, the exhaust groove group 5 includes a first exhaust groove 51 and a second exhaust groove 52. The first exhaust groove 51 is connected to the cavity 3 and the second exhaust groove 52 respectively. The depth of the first exhaust groove 51 is not greater than the depth of the second exhaust groove 52.

[0045] Specifically, in some embodiments of this application, the first exhaust groove 51 is a shallow exhaust groove with a depth of 0.015 mm, and the second exhaust groove 52 is a deep exhaust groove with a depth of 0.2 mm. Of course, there is no limitation on the specific depth of the first exhaust groove 51 and the second exhaust groove 52.

[0046] Understandably, the first venting groove 51, which communicates with the cavity 3, is relatively shallow and is mainly used to expel the compressed gas during filling. Compared to the deeper second venting groove 52, the molten plastic is less likely to penetrate into the first venting groove 51 under high pressure and high speed, which can reduce the formation of flash and burrs, and also reduce the possibility of the molten plastic blocking the venting groove group 5. If the depth of the first venting groove 51 is set to 0.01 mm to 0.03 mm, the low viscosity of the gas can easily pass through, while the surface of the molten plastic has a skin and surface tension, making it difficult to penetrate. Then, gradually transitioning to the second venting groove 52, the second venting groove 52 is used to increase the venting capacity, ensuring timely air discharge and reducing problems such as end-point air trapping, scorching, short shots, and loose weld lines caused by too small a venting area.

[0047] In an optional embodiment, such as Figure 7 As shown, an exhaust groove group 5 is provided between the first mold core 12 and the second mold core 22, which is distributed at intervals along the cavity 3; like Figure 8As shown, a plurality of venting groove groups 5 are provided between the sliding member 23 and the first mold core 12 and / or the second mold core 22. All the first venting grooves 51 are continuously arranged along the length direction of the cavity 3. Each second venting groove 52 is connected to the first venting groove 51 and is arranged at intervals corresponding to the first venting groove 51.

[0048] Among them, a number of venting groove groups 5 are provided between the sliding member 23 and the first mold core 12 and / or the second mold core 22. No gaps are left between the shallow venting grooves, which can improve the venting speed to a certain extent and achieve rapid venting.

[0049] Understandably, the parting surface between the first mold core 12 and the second mold core 22 not only needs to vent but also needs to withstand the clamping force. The spaced distribution of the venting groove group 5 provides sufficient solid bands for the sealing surface, which can not only realize the venting function but also reduce the impact on the bonding stability of the first mold core 12 and the second mold core 22 and reduce the misalignment between the first mold core 12 and the second mold core 22. The venting groove group 5 between the sliding member 23 and the first mold core 12 and / or the second mold core 22 is continuously arranged. The sliding member 23 slides with the first mold core 12 and / or the second mold core 22 and usually needs to slide back and forth during use. The continuous arrangement of the first venting groove 51 and the continuous arrangement of the second venting groove 52 can reduce the obstruction to the sliding of the sliding member 23, improve the smoothness of the sliding process, and reduce the wear of the venting groove group 5, so as to avoid the instability of the chin part molding effect after wear to a certain extent.

[0050] In an optional embodiment, combined with Figure 9 and Figure 10 As shown, the molding module is also equipped with a zoned cooling system; The zoned cooling system includes a first cooling module 61, a second cooling module 62, and a third cooling module 63; The first cooling module 61 is disposed at least through the first mold core 12, the second cooling module 62 is disposed at least through the second mold core 22, and the third cooling module 63 is disposed at least through the sliding member 23. The first mold assembly 1 is used to fit the second mold assembly 2 so that the multi-point needle valve feeding system 4 and the cavity 3 are located in the area formed by the partitioned cooling system.

[0051] Specifically, in some embodiments of this application, temperature sensors are provided at the locations corresponding to the first cooling module 61, the second cooling module 62, and the third cooling module 63 to detect the actual temperature of the corresponding cooling modules and further control the temperature of the different cooling modules.

[0052] Understandably, the first cooling module 61 is installed in the first mold core 12, the second cooling module 62 is installed in the second mold core 22, and the third cooling module 63 is installed in the sliding member 23. This achieves zoned control of the first cooling module 61, the second cooling module 62, and the sliding member 23, which can adapt to the cooling needs of different parts of different cavities 3 and achieve differentiated control to optimize the molding effect of the chin part. After the first mold assembly 1 is attached to the second mold assembly 2, the multi-point needle valve feeding system 4 and the cavity 3 are located in the area formed by the zoned cooling system, which can cool the chin part from multiple aspects and angles. The mold temperature field presents a stable state with high internal temperature and water cooling around the perimeter, which makes the temperature decay of the flow front slower and the skin formation rate more uniform, thus optimizing the formation effect of the chin part's appearance texture. The first cooling module 61 and the second cooling module 62 cool the chin part from the top and bottom, and the temperature of the upper and lower molds is stacked, which reduces the occurrence of chin part warping and thus reduces the gap formed after the chin part is assembled with the display.

[0053] In addition, the third cooling module 63 is installed through the slider 23, which helps to cool the slider 23, maintain the stability of the demolding temperature, and reduce the possibility of damage to the chin part during demolding.

[0054] Specifically, in an optional embodiment, the first cooling module 61 includes a first cavity cooling water channel 611 and a first feed cooling water channel 612. The first cavity cooling water channel 611 extends along the length direction of the cavity 3, and the first feed cooling water channel 612 is spaced apart along the length direction of the first cavity cooling water channel 611 so as to be staggered with the first cavity cooling water channel 611. The second cooling module 62 includes a second cavity cooling water channel 621 and a second feed cooling water channel 622. The extension direction of the second cavity cooling water channel 621 is the same as that of the second feed cooling water channel 622. The second cavity cooling water channel 621 and the second feed cooling water channel 622 are arranged along the plastic flow direction and are staggered with the first feed cooling water channel 612. The third cooling module 63 includes a slider cooling water channel 631, which is arranged along the sliding direction of the slider 23 and is located between the first cavity cooling water channel 611 and the second cavity cooling water channel 621. The first mold assembly 1 is used to fit the second mold assembly 2 so that the partitioned cooling system cools the multi-point needle valve feeding system 4 and the cavity 3 from at least two directions.

[0055] More specifically, in some embodiments of this application, the first cavity cooling water channel 611 and the first feed cooling water channel 612 have a pipe diameter of 8mm and an applicable temperature of 80℃; the second cavity cooling water channel 621 and the second feed cooling water channel 622 have a pipe diameter of 10mm and an applicable temperature of 85℃; the slider cooling water channel 631 has a pipe diameter of 10mm and an applicable temperature of 85℃. The first mold assembly 1 is used to fit against the second mold assembly 2 so that the partitioned cooling system cools the multi-point needle valve feed system 4 and the cavity 3 from at least three directions. Of course, there are no specific limitations on the pipe diameter and temperature of each cooling water channel.

[0056] Understandably, in the first cooling module 61, the first cavity cooling water channel 611 extends along the length of the cavity 3 to cover the entire sidewall of the elongated chin part, which can suppress warping of the chin part during molding to a certain extent; the first feed cooling water channel 612 is distributed at intervals along the length of the first cavity cooling water channel 611 to form a grid-like layout, which is used to cool different gates 44 and cold runners 43, and can specifically cool the local heat of the gate 44 part; in the second cooling module 62, the second cavity cooling water channel 621 and the second feed cooling water channel 622 extend in the same direction, are arranged along the plastic flow direction, and are arranged in parallel to conform to the temperature decay law of plastic melt filling, realizing gradient cooling, and are distributed in an alternating manner with the first feed water flow, realizing thermal isolation of the multi-point needle valve 42 inlet, avoiding heat accumulation in multiple areas.

[0057] The first cooling module 61, the second cooling module 62, and the third cooling module 63 work together to form a three-dimensional cooling network. The first cooling module 61 and the second cooling module 62 mainly cool the chin part from both sides along the length of the cavity 3, while the third cooling module 63 cools the chin part from the side to make up for the insufficient cooling of the first cooling module 61 and the second cooling module 62 at the sliding part 23.

[0058] like Figure 6 As shown, in an optional embodiment, each cold runner 43 is provided with a sub-runner 431 with progressively decreasing flow rates from near to far, and the end sub-runner 431 is connected to the cavity 3 through a gate 44. A cooling section 432 is provided at the connection of each sub-channel 431. The cooling section 432 extends along the extension direction of the previous sub-channel 431 so that the plastic flows through the cooling section 432 at least partially due to inertia, and then flows to each next sub-channel 431, so that the temperature and fluidity of the plastic entering the cavity 3 meet the preset target. The volume of each cooling section 432 is related to one or more of the flow rate, flow length and flow curvature of the sub-flow channel 431.

[0059] Understandably, by designing the cold runner 43 with graded flow rates, the flow rate of each sub-runner 431 decreases sequentially along the flow direction, effectively matching the pressure and flow rate attenuation characteristics of the melt during the flow process. This avoids the problem of incomplete filling in the far-end area due to insufficient pressure to a certain extent, and matches the end effect of the plastic melt flow, which helps to ensure the balance of material supply in each area of ​​the cavity 3.

[0060] Specifically, in some embodiments of this application, the sidewalls of the cavity 3 are etched with textures so that at least part of the surface of the chin piece forms a matte textured finish after injection molding.

[0061] The cooling section 432 extends along the extension direction of the previous sub-channel 431. It utilizes the inertia of the melt flow to induce the low-temperature plastic at the front end to remain, so that the plastic melt is at least partially flowing through the cooling section 432 under inertial action, and then flowing to each of the next sub-channels 431. This allows the lower-temperature plastic melt to directly enter the cooling section 432, and the cooling section 432 completes the gradual replacement of the plastic melt, thereby ensuring the temperature and fluidity of the plastic entering the cavity 3. This ensures that the plastic entering the 0.5mm thin-walled cavity 3 maintains the optimal temperature and good fluidity, which is beneficial for filling thin-walled or complex-structured cavities 3, and reduces internal stress and deformation problems caused by temperature differences, thereby optimizing the texture preparation effect of the chin part.

[0062] The volume of each cooling section 432 is set according to the flow channel conditions at its location. The volume of the cooling section 432 matches at least one of the parameters of the corresponding sub-flow channel 431: flow rate, flow channel length, and flow channel curvature. The higher the flow rate, the longer the flow channel, or the greater the curvature, the larger the volume of the cooling section 432 at the corresponding location will be, so as to ensure sufficient stagnation space during the heat exchange process, thereby accurately controlling the temperature of the plastic entering the cavity 3.

[0063] This application also provides an injection molding method, such as... Figure 11 As shown, injection molding is performed using an injection mold, and the method includes: 100, Obtain the injection molding effect requirements and generate the injection molding signal; 200, based on the injection signal, control the opening and closing sequence, opening and closing time and opening and closing degree of different needle valves in the multi-point needle valve feeding system; 300, the molten plastic material is injected into the cavity in sections through the multi-point needle valve feeding system; 400, and the gas in the cavity is passively removed in stages through the venting grooves set on the injection mold; 500, and according to the injection signal, control the cooling temperature, cooling time and cooling sequence of different cooling modules in the partitioned cooling system set on the injection mold to complete the injection molding of the chin part.

[0064] Understandably, the injection molding effect requirement is for the chin part to have a consistent overall appearance, and injection signals are generated based on this requirement. To achieve a consistent injection molding effect, the opening and closing sequence, opening and closing time, and opening and closing degree of different needle valves 42 in the multi-point needle valve 42 injection molding system can be controlled to maintain correspondence, so that the plastic is injected into the cavity 3 synchronously or nearly synchronously from multiple paths. The plastic fusion time is consistent, effectively solving problems such as air entrapment, weld lines, and uneven shrinkage caused by single-point injection, and significantly improving the surface flatness and appearance consistency of the chin part.

[0065] By passively expelling the gas in cavity 3 through the five-stage exhaust channel group, the formation of flash and burrs can be reduced, ensuring timely air discharge and reducing problems such as end-stage air entrapment, scorching, short shots, and loose weld lines caused by insufficient exhaust area.

[0066] Furthermore, by using a zoned cooling system to cool the chin component in sections, the deformation of the chin component can be reduced, and warping can be minimized, thereby achieving good appearance consistency and meeting the injection molding requirements of the chin component.

[0067] The embodiments of this application have at least the following beneficial effects: This application provides a molding die for a thin, elongated chin piece, which reduces the difficulty of injection molding control for the chin piece, improves the stability and flexibility of the chin piece's appearance preparation, and effectively meets the actual needs of the chin piece. Specifically, the mold includes a multi-point needle valve feeding system 4, which includes a hot runner 41, a cold runner 43, and needle valves 42 connected in sequence. Several cold runners 43 are connected to the cavity 3. On the one hand, it can control different areas within the cavity 3, effectively reducing the difficulty of injection molding control. On the other hand, it shortens the flow length of a single injection path, effectively reducing short shots and excessive pressure, and improving the aesthetics and molding stability of the chin part. Furthermore, by controlling the opening and closing sequence, opening and closing time, and opening and closing degree of different needle valves 42, different areas on the chin part can present consistent or different injection molding effects to meet the actual appearance requirements of the chin part. The cooling section 432 extends along the extension direction of the previous sub-channel 431. It uses the inertia of the melt flow to induce the low-temperature plastic at the front end to stay, and then flow to each of the next sub-channels 431. This allows the lower-temperature plastic melt to directly enter the cooling section 432. The cooling section 432 completes the gradual replacement of the plastic melt, thereby ensuring the temperature and fluidity of the plastic entering the cavity 3. This keeps the plastic entering the cavity 3 at the optimal temperature and good fluidity, and reduces the internal stress and deformation problems caused by temperature difference. The end sub-flow channel 431 is connected to the cavity through the flat gate 44, which effectively improves the expansion effect of the plastic melt, reduces flow resistance and mold filling pressure, and reduces plastic residue. It effectively improves the fluidity of the plastic in the cavity 3 and reduces the generation of cold material marks to a certain extent. The molding die for the thin, elongated chin part is also equipped with an exhaust groove group 5, which effectively solves the problem of gas retention during the injection molding process and largely avoids problems such as scorching, insufficient filling, flash and black shadow caused by trapped air. By optimizing the preparation effect of thin-bodied elongated chin parts such as chin parts through the partitioned feeding of the multi-point needle valve feeding system 4, the graded structure of the cold runner 43, the partitioned venting of the venting groove group 5, and the coordinated operation of the side fan-shaped gate 44, the molding quality of the product is improved.

[0068] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of a preferred embodiment, and the modules or processes shown in the drawings are not necessarily essential for implementing this application.

[0069] Those skilled in the art will understand that the modules in the apparatus of the implementation scenario can be distributed within the apparatus of the implementation scenario as described, or they can be located in one or more apparatuses different from this implementation scenario, with corresponding changes. The modules of the above-described implementation scenario can be combined into one module, or they can be further divided into multiple sub-modules.

[0070] The serial numbers in this application are for descriptive purposes only and do not represent the superiority or inferiority of the implementation scenario.

[0071] The above disclosures are only a few specific implementation scenarios of this application. However, this application is not limited to these. Any variations that can be conceived by those skilled in the art should fall within the protection scope of this application.

Claims

1. A molding die for a thin, elongated chin piece, characterized in that, In the process of manufacturing a thin, elongated chin piece, the mold includes: First mold assembly; The second mold assembly can cooperate with the first mold assembly to form a plurality of thin, elongated cavities; A multi-point needle valve feeding system is installed on the first mold assembly. The multi-point needle valve feeding system includes a hot runner, a needle valve, and a cold runner connected in sequence. Several cold runners are distributed along the extension direction of the cavity and are respectively connected to the cavity so that each cold runner corresponds to a different area of ​​the cavity. The hot runner is connected to the cold runner through a needle valve. The multi-point needle valve feeding system is used to control the opening and closing sequence, opening and closing time and opening and closing degree of different needle valves during the injection molding process so that different areas on the chin part present a consistent injection molding effect. The cold runner is connected to the cavity through a gate, which is flat and gradually expands in the direction close to the cavity; The mold is also provided with a group of venting grooves, which are located in one or more of the parting surface, the flow end, the slider area, or the melt confluence area.

2. The molding die for the thin, elongated chin piece according to claim 1, characterized in that, The first mold assembly includes a first template and a first mold core, and the second mold assembly includes a second template, a second mold core, and a sliding component; The first mold assembly is used to fit with the second mold assembly to form at least two cavities between the first mold core, the second mold core and the sliding member; The multi-point needle valve feeding system is connected to the at least two cavities respectively, so that the chin parts located in different cavities present a consistent injection molding effect.

3. The molding die for the thin, elongated chin piece according to claim 2, characterized in that, The venting groove group includes a first venting groove and a second venting groove, wherein the first venting groove is connected to the cavity and the second venting groove respectively; The depth of the first exhaust groove is not greater than the depth of the second exhaust groove.

4. The molding die for the thin, elongated chin piece according to claim 3, characterized in that, The first mold core and the second mold core are provided with the venting groove group distributed along the cavity spacing; A plurality of venting groove groups are provided between the sliding member and the first mold core and / or the second mold core. All the first venting grooves are continuously arranged along the length direction of the cavity. Each second venting groove is connected to the first venting groove and is arranged at intervals corresponding to the first venting groove.

5. The molding die for the thin, elongated chin piece according to claim 2, characterized in that, It also features a zoned cooling system; The partitioned cooling system includes a first cooling module, a second cooling module, and a third cooling module; The first cooling module is disposed at least through the first mold core, the second cooling module is disposed at least through the second mold core, and the third cooling module is disposed at least through the sliding member; The first mold assembly is used to fit the second mold assembly so that the multi-point needle valve feeding system and the cavity are located in the area formed by the partitioned cooling system.

6. The molding die for the thin, elongated chin piece according to claim 5, characterized in that, The first cooling module includes a first cavity cooling water channel and a first feed cooling water channel. The first cavity cooling water channel extends along the length direction of the cavity, and the first feed cooling water channel is spaced apart along the length direction of the first cavity cooling water channel so as to be staggered with the first cavity cooling water channel. The second cooling module includes a second cavity cooling water channel and a second feed cooling water channel. The extension direction of the second cavity cooling water channel is the same as that of the second feed cooling water channel. The second cavity cooling water channel and the second feed cooling water channel are arranged along the plastic flow direction, so as to be staggered with the first feed cooling water channel. The third cooling module includes a slider cooling water channel, which is arranged along the sliding direction of the slider and located between the first cavity cooling water channel and the second cavity cooling water channel. The first mold assembly is used to fit the second mold assembly so that the partitioned cooling system cools the multi-point needle valve feeding system and the cavity from at least two directions.

7. The molding die for the thin, elongated chin piece according to claim 1, characterized in that, Each of the cold runners is provided with sub-runners of progressively decreasing flow rate from near to far, and the end sub-runner is connected to the cavity through the gate; A cooling section is provided at the connection point of each sub-channel. The cooling section extends along the extension direction of the previous sub-channel so that the plastic flows through the cooling section at least partially due to inertia, and then flows to each of the next sub-channels, so that the temperature and fluidity of the plastic entering the cavity meet the preset target.

8. An injection molding method, characterized in that, Injection molding is performed using the injection mold according to any one of claims 1 to 7, the method comprising: Obtain the required injection molding effect and generate injection signals; Based on the injection signal, control the opening and closing sequence, opening and closing time and opening and closing degree of different needle valves in the multi-point needle valve feeding system; The molten plastic material is injected into the mold cavity through a multi-point needle valve feeding system; And the gas in the cavity is passively removed in stages through the venting grooves set on the injection mold; Furthermore, based on the injection signal, the cooling temperature, cooling time, and cooling sequence of different cooling modules in the partitioned cooling system set on the injection mold are controlled to complete the injection molding of the chin part.

Images