Highlight traceless injection mold

By setting up a medium flow channel in the injection mold to control the mold temperature, the problems of cold slug marks, gate marks, and weld lines are solved, resulting in a high-gloss surface finish on injection molded parts and improved production efficiency.

CN224255949UActive Publication Date: 2026-05-19TAICANG QIUJING PLASTIC MOLD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
TAICANG QIUJING PLASTIC MOLD
Filing Date
2025-05-30
Publication Date
2026-05-19

AI Technical Summary

Technical Problem

Existing injection molds are prone to producing cold slug marks, gate marks, and weld lines during the molding process, resulting in poor surface finish of injection molded parts, low production efficiency, and high costs.

Method used

An injection mold consisting of an upper mold and a lower mold was designed. Medium flow channels were set in the upper mold core and the lower mold core respectively. The mold temperature was controlled by the medium flow channels. The mold was heated to above the softening point of the plastic before injection and cooled and solidified quickly after injection to avoid cold material marks and gate marks. High pressure and high speed injection molding was ensured by locking blocks.

Benefits of technology

It achieves a high-gloss surface finish on injection molded parts, improves production efficiency and quality, avoids cold runner marks, gate marks and weld lines, and reduces production costs.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model provides a highlight traceless injection mold, which comprises an upper mold, a lower mold, a lower mold and a lower mold, and is characterized in that the upper mold comprises an upper mold frame, an upper mold core embedded on the bottom surface of the upper mold frame, and an injection molding runner arranged in the upper mold frame and communicated with the upper mold core; the injection molding runner sequentially comprises a main runner and a branch runner from top to bottom, the main runner is communicated with the branch runner, the branch runner is embedded in the upper mold core, a bottom injection port of the branch runner is flush with the bottom surface of the upper mold core, and a first medium runner is arranged in the upper mold core; the lower die comprises a lower die frame and a lower die core arranged on the lower die frame, the lower die core and the upper die core are combined to form a cavity, the branch runners are communicated with the cavity, a second medium runner is arranged in the lower die frame, and the second medium runner flows through the interior of the lower die core; the injection mold further comprises a mold base arranged at the bottom of the lower mold, and an ejection assembly used for ejecting a product is arranged on the mold base. The high-gloss traceless injection molding device can realize high-quality high-gloss traceless injection molding and is beneficial to improving the injection molding efficiency.
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Description

Technical Field

[0001] This utility model belongs to the field of injection mold technology, and specifically relates to a high-gloss, traceless injection mold. Background Technology

[0002] Injection molds are tools used to produce plastic products, giving them precise dimensions and complete structures. With the booming development of the manufacturing industry, injection molding processes need to meet the demands of manufacturing more complex parts.

[0003] The manufacturing of exterior components for home appliances, automotive interiors, and 3C products requires high-gloss, seamless injection molding to achieve a high-gloss (near-mirror) and low-roughness surface. However, using existing injection molds results in suboptimal processing quality, leading to the following problems:

[0004] 1. Cold material marks are generated on the surface of the workpiece during the molding process, which affects the surface effect of the molded workpiece and requires reprocessing after demolding. This is also a factor leading to low production efficiency and high production costs.

[0005] 2. Gate marks generated during injection molding affect the appearance. Utility Model Content

[0006] Purpose of the utility model: In order to overcome the above shortcomings, this utility model provides a high-gloss, traceless injection mold with a simple structure and reasonable design, which improves injection molding efficiency and quality.

[0007] Technical solution: To achieve the above objectives, this utility model provides a high-gloss, seamless injection mold, comprising:

[0008] The upper mold includes an upper mold frame, an upper mold core fitted into the bottom surface of the upper mold frame, and an injection runner disposed within the upper mold frame and communicating with the upper mold core;

[0009] The injection runner system includes a main runner and a branch runner from top to bottom. The main runner and the branch runner are connected. The branch runner is embedded in the upper mold core, and the bottom injection port of the branch runner is flush with the bottom surface of the upper mold core. The upper mold core is provided with a first medium runner. A cold or hot medium is introduced into the first medium runner to cool or heat the upper mold core.

[0010] The lower mold includes a lower mold frame and a lower mold core disposed on the lower mold frame. The lower mold core and the upper mold core are combined to form a cavity. The branch channel is connected to the cavity. A second medium flow channel is provided inside the lower mold frame. The second medium flow channel flows through the interior of the lower mold core. A cold or hot medium is introduced into the second medium flow channel to cool or heat the lower mold core.

[0011] It also includes a mold base located at the bottom of the lower mold, wherein the mold base is provided with an ejection assembly for ejecting the product.

[0012] Furthermore, the upper mold frame is provided with a first medium flow channel interface on its side, and the first medium flow channel interface is connected to the first medium flow channel;

[0013] The lower mold frame is provided with a second medium flow channel interface on its side, and the second medium flow channel interface is connected to the second medium flow channel;

[0014] Both the first and second media flow channel interfaces are connected to the mold temperature controller.

[0015] Furthermore, the upper mold also includes a top plate, which is provided with an injection positioning port, which is concentrically arranged with and connected to the main runner.

[0016] Furthermore, the lower mold core is provided with forming blocks around its perimeter. The forming blocks are slidably mounted on the lower mold frame via a sliding groove. The forming blocks are wedge-shaped with inclined outer surfaces. The bottom surface of the upper mold frame is provided with a wedge-shaped groove that fits with the forming blocks.

[0017] Furthermore, the lower mold core has guide posts on its four sides, and the inner side of the molding block has guide holes that cooperate with the guide posts for guidance. The side of the molding block that contacts the lower mold core has a groove, and the groove and the cavity together form the injection molding cavity. The guide holes on the molding block cooperate with the guide posts to ensure a precise fit between the molding block and the lower mold core.

[0018] Furthermore, the mold base includes a base plate and a set of mold feet, the mold feet being located on both sides of the base plate, and an ejection hole being provided at the center of the base plate.

[0019] Furthermore, the ejection assembly includes a lifting plate, a plurality of ejector pins, and a limiting post that contacts and limits the bottom surface of the lower mold base. The lifting plate is disposed between the mold feet, the ejector pins are disposed on the lifting plate, and the limiting post is disposed on the lifting plate.

[0020] The lifting plate is connected to an external ejection lifting device through an ejection hole, and the ejector pin can pass through the lower mold core to eject the injection molded part.

[0021] Furthermore, the upper and lower molds are provided with locking holes on their sides, and locking blocks for locking the upper and lower molds are provided in the locking holes.

[0022] Furthermore, the lower mold frame is provided with vent holes on its side.

[0023] As can be seen from the above technical solution, this utility model has the following beneficial effects:

[0024] 1) This utility model provides a high-gloss, seamless injection mold. By designing media channels in the upper and lower mold cores, different media can be introduced at different stages to control the mold temperature. Before injection, the mold temperature is raised above the plastic softening point, allowing the melt to quickly fill and replicate the high-gloss effect on the mold surface. After injection, it cools down and solidifies quickly to prevent surface shrinkage. 2) At the same time, the runner is embedded in the upper mold core. During injection, the temperature of the lower mold core can effectively prevent the plastic from cooling down in the runner and generating weld lines, cloud patterns, and cold material marks. In addition, the injection port of the runner is flush with the bottom surface of the upper mold core to avoid gate marks affecting the appearance. 3) A separate locking block is designed on the mold for locking. During injection, the injection molding machine can inject at a higher speed and pressure, ensuring complete filling of the injection molded part. Attached Figure Description

[0025] Figure 1 This is a structural schematic diagram of a high-gloss, seamless injection mold according to the present invention;

[0026] Figure 2 This is an exploded view of a high-gloss, traceless injection mold according to the present invention;

[0027] Figure 3 This is a bottom view of a high-gloss, seamless injection mold according to the present invention;

[0028] Figure 4 This is a top view of a high-gloss, seamless injection mold according to the present invention.

[0029] Figure 5 This is a schematic diagram of the structure of the upper mold described in this utility model;

[0030] Figure 6 This is a schematic diagram of the assembly of the branch channel and the upper mold core according to the present invention;

[0031] Figure 7 for Figure 6 A cross-sectional view;

[0032] Figure 8 This is a schematic diagram of the structure of the lower mold described in this utility model;

[0033] Figure 9 for Figure 8 A cross-sectional view;

[0034] Figure 10 This is a schematic diagram of the structure of the molding block described in this utility model.

[0035] In the diagram: 100-Upper mold, 101-Upper mold base, 1011-First medium flow channel interface, 102-Upper mold core, 103-Injection runner, 1031-Main runner, 1032-Branch runner, 1033-First medium flow channel, 104-Top plate, 1041-Injection positioning port;

[0036] 200-Lower mold, 201-Lower mold base, 2011-Second medium flow channel opening, 2012-Vent hole, 202-Lower mold core, 2021-Forming block, 2022-Guide post, 2023-Forming groove, 203-Second medium flow channel;

[0037] 300 - Mold base, 301 - Base plate, 3011 - Ejector hole, 302 - Mold foot;

[0038] 400-Ejection assembly, 401-Lifting plate, 402-Ejector pin, 403-Limiting post;

[0039] 501 - Lock hole, 502 - Lock block. Detailed Implementation

[0040] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] like Figure 1-10 As shown, a high-gloss, seamless injection mold includes:

[0042] The upper mold 100 includes an upper mold frame 101, an upper mold core 102 fitted into the bottom surface of the upper mold frame 101, and an injection runner 103 disposed in the upper mold frame 101 and communicating with the upper mold core 102.

[0043] The injection runner 103 includes a main runner 1031 and a branch runner 1032 from top to bottom. The main runner 1031 and the branch runner 1032 are connected. The branch runner 1032 is embedded in the upper mold core 102, and the bottom injection port of the branch runner 1032 is flush with the bottom surface of the upper mold core 102. The upper mold core 102 is provided with a first medium flow channel 1033. The injection port of the branch runner 1032 and the upper mold core 102 form a submarine gate to avoid gate marks affecting the appearance.

[0044] The lower mold 200 includes a lower mold frame 201 and a lower mold core 202 disposed on the lower mold frame 200. The lower mold core 202 and the upper mold core 102 are combined to form a cavity. The branch channel 1032 communicates with the cavity. The lower mold frame 201 is provided with a second medium flow channel 203, which flows through the interior of the lower mold core 202.

[0045] It also includes a mold base 300 located at the bottom of the lower mold 200, and the mold base 300 is provided with an ejection assembly 400 for ejecting the product.

[0046] In this embodiment, the upper mold core 102 and the lower mold core 202 are made of copper, which achieves better thermal conductivity. The medium flowing through the first medium channel 1033 and the second medium channel 203 can quickly cool or heat the upper mold core 102 and the lower mold core 202. In addition, depending on the size of the upper mold core 102 and the lower mold core 202, the first medium channel 1033 and the second medium channel 203 can be designed as straight-through for smaller upper mold cores 102 and lower mold cores 202, and can be designed as spiral for larger upper mold cores 102 and lower mold cores 202, thereby increasing their effective area.

[0047] The upper mold frame 101 is provided with a first medium flow channel interface 1011 on its side, and the first medium flow channel interface 1011 is connected to the first medium flow channel 1034.

[0048] The lower mold frame 201 is provided with a second medium flow channel interface 2011 on its side, and the second medium flow channel interface 2011 is connected to the second medium flow channel 203;

[0049] Both the first medium flow channel interface 1011 and the second medium flow channel interface 2011 are connected to a mold temperature controller. The mold temperature controller injects medium into the first medium flow channel 1033 and the second medium flow channel 203, and indirectly controls the temperature of the mold by controlling the temperature of the medium.

[0050] Specifically, the upper mold 100 also includes a top plate 104, on which an injection positioning port 1041 is provided. The injection positioning port 1041 is concentrically arranged with and communicates with the main runner 1031. The mold can be quickly connected to the injection molding machine through the injection positioning port 1041.

[0051] Specifically, the lower mold core 202 is surrounded by forming blocks 2021, which are slidably mounted on the lower mold frame 201 via grooves. Each forming block 2021 is wedge-shaped with an inclined outer surface. The bottom surface of the upper mold frame 101 has a wedge-shaped groove that fits into the forming blocks 2021. During mold closing, the wedge-shaped groove on the bottom surface of the upper mold frame 101 engages with the forming blocks 2021, ensuring a tight fit between the forming blocks 2021 and the lower mold core 202.

[0052] Specifically, the lower mold core 202 has guide posts 2022 on its four sides, the inner side of the molding block 2021 has guide holes that cooperate with the guide posts 2022 for guidance, and the side of the molding block 2021 that contacts the lower mold core 202 has a groove 2023. The groove and the cavity together form the injection molding cavity.

[0053] Specifically, the mold base 300 includes a base plate 301 and a set of mold feet 302. The mold feet are located on both sides of the base plate 301, and the center of the base plate 301 is provided with an ejection hole 3011.

[0054] In a preferred embodiment, the ejection assembly 400 includes a lifting plate 401, a plurality of ejector pins 402, and a limiting post 403 that contacts and limits the bottom surface of the lower mold frame 201. The lifting plate 401 is disposed between the mold feet 302, the ejector pins 402 are disposed on the lifting plate 401, and the limiting post 403 is disposed on the lifting plate 401.

[0055] The lifting plate 401 is externally connected to the ejection lifting device through the ejection hole 3011, and the ejector pin 402 can pass through the lower mold core 202 to eject the injection molded part.

[0056] Specifically, the upper mold 100 and the lower mold 200 are provided with locking holes 501 on their sides, and locking blocks 502 for locking the upper mold 100 and the lower mold 200 are provided in the locking holes. After the upper mold 100 and the lower mold 200 are closed, they are locked together by the locking blocks 502 and the locking holes 501, so that high pressure and high speed injection can be used during injection molding to ensure complete filling of the injection molded part.

[0057] Specifically, the lower mold base 201 is provided with vent holes 2012 on its side. The vent holes 2012 discharge excess gas from the mold, preventing bubble defects from forming on the injection molded part.

[0058] In this embodiment, a high-gloss, seamless injection mold is disclosed. Before injection, a high-temperature medium, such as high-temperature steam, is injected into the first medium flow channel 1033 and the second medium flow channel 203 by a mold temperature controller. This heats the mold temperature to above the plastic softening temperature, allowing the melt to quickly fill and replicate the high-gloss effect on the mold surface. Simultaneously, during injection, the branch channel 1032 is located in the high-temperature upper mold core 102, effectively preventing the formation of weld lines and cloud patterns on the cooling surface of the material in the injection flow channel 103. After injection, rapid cooling and solidification are achieved by introducing cooling media through the first medium flow channel 1033 and the second medium flow channel 203. Finally, the injection molded part is ejected by the ejection assembly 400.

[0059] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present utility model, and these improvements should also be considered within the protection scope of the present utility model.

Claims

1. A high-gloss, seamless injection mold, characterized in that, include: The upper mold (100) includes an upper mold frame (101), an upper mold core (102) fitted into the bottom surface of the upper mold frame (101), and an injection runner (103) located in the upper mold frame (101) and connected to the upper mold core (102). The injection runner (103) includes a main runner (1031) and a branch runner (1032) from top to bottom. The main runner (1031) and the branch runner (1032) are connected. The branch runner (1032) is embedded in the upper mold core (102). The bottom injection port of the branch runner (1032) is flush with the bottom surface of the upper mold core (102). The upper mold core (102) is provided with a first medium runner (1033). The lower mold (200) includes a lower mold frame (201) and a lower mold core (202) disposed on the lower mold frame (201). The lower mold core (202) and the upper mold core (102) are combined to form a cavity. The branch channel (1032) communicates with the cavity. The lower mold frame (201) is provided with a second medium flow channel (203), which flows through the interior of the lower mold core (202). It also includes a mold base (300) located at the bottom of the lower mold (200), and the mold base (300) is provided with an ejection assembly (400) for ejecting the product.

2. The high-gloss, seamless injection mold according to claim 1, characterized in that, The upper mold frame (101) is provided with a first medium flow channel interface (1011) on its side, and the first medium flow channel interface (1011) is connected to the first medium flow channel (1033); The lower mold frame (201) is provided with a second medium flow channel interface (2011) on its side, and the second medium flow channel interface (2011) is connected to the second medium flow channel (203); Both the first medium flow channel interface (1011) and the second medium flow channel interface (2011) are connected to the mold temperature controller.

3. The high-gloss, seamless injection mold according to claim 1, characterized in that, The upper mold (100) also includes a top plate (104), on which an injection positioning port (1041) is provided. The injection positioning port (1041) is concentrically arranged with and connected to the main channel (1031).

4. The high-gloss, seamless injection mold according to claim 1, characterized in that, The lower mold core (202) is provided with forming blocks (2021) around its perimeter. The forming blocks (2021) are slidably mounted on the lower mold frame (201) via a sliding groove. The forming blocks (2021) are wedge-shaped with an inclined outer surface. The bottom surface of the upper mold frame (101) is provided with a wedge-shaped groove that fits with the forming blocks (2021).

5. A high-gloss, seamless injection mold according to claim 4, characterized in that, The lower mold core (202) has guide posts (2022) on its four sides. The inner side of the molding block (2021) has guide holes that cooperate with the guide posts (2022) for guidance. The side of the molding block (2021) that contacts the lower mold core (202) has a groove (2023). The groove and the cavity together form an injection molding cavity.

6. A high-gloss, seamless injection mold according to claim 1, characterized in that, The mold base (300) includes a base plate (301) and a set of mold feet (302). The mold feet are located on both sides of the base plate (301), and the center of the base plate (301) is provided with an ejection hole (3011).

7. A high-gloss, seamless injection mold according to claim 6, characterized in that, The ejection assembly (400) includes a lifting plate (401), a plurality of ejector pins (402), and a limiting post (403) that contacts and limits the bottom surface of the lower mold frame (201). The lifting plate (401) is located between the mold feet (302), the ejector pins (402) are located on the lifting plate (401), and the limiting post (403) is located on the lifting plate (401). The lifting plate (401) is externally connected to the ejection lifting device through the ejection hole (3011), and the ejector pin (402) can pass through the lower mold core (202) to eject the injection molded part.

8. A high-gloss, seamless injection mold according to claim 1, characterized in that, The upper mold (100) and the lower mold (200) are provided with locking holes (501) on their sides, and locking blocks (502) for locking the upper mold (100) and the lower mold (200) are provided in the locking holes.

9. A high-gloss, seamless injection mold according to claim 1, characterized in that, The lower mold frame (201) has an exhaust hole (2012) on its side.