Glue feeding structure of double-injection mold

Abstract

The utility model provides a glue inlet structure of a double-injection mould, which comprises a mould closing mechanism, the mould closing mechanism comprises a front mould and a rear mould, during mould closing, the front mould and the rear mould are enclosed to form an accommodating cavity, a main pouring gate and a straight runner are arranged in the mould closing mechanism, and the main pouring gate is communicated with a straight glue inlet of the straight runner; a side runner is further arranged in the mold closing mechanism, a straight glue outlet of the straight runner is communicated with a side glue inlet of the side runner, a side glue outlet of the side runner is communicated with the containing cavity, and the glue outlet area S1 of the side glue outlet is larger than the glue outlet area S2 of the straight glue outlet. By combining the C-shaped side runner and the fan-shaped glue feeding design, the appearance defects, such as gas marks and material flowers, of a bijection transparent product caused by an improper glue feeding mode are overcome, meanwhile, the melt flowing path and shearing heat distribution are optimized, melt turbulence is reduced, the serpentine flow marks and the scorching defects are eliminated, and the appearance requirement of the high-transparency product is met.

Description

Technical Field

[0001] This utility model belongs to the field of injection molding processing technology, specifically relating to a glue injection structure for a double-shot mold. Background Technology

[0002] In the field of plastic molds, two-shot molding technology is widely used, especially when producing complex plastic products with different materials or colors. Two-shot molding can achieve the molding of two different materials in one step, improving production efficiency and reducing production costs. However, for some special products, the requirements for appearance and performance are extremely high, and there are strict requirements for transparency and surface quality. Traditional injection methods have many problems when producing such products and are difficult to meet the high-quality production needs.

[0003] Existing injection molding methods mainly include direct side injection and dot injection. Although direct side injection is simple in structure, it can easily lead to defects such as air bubbles and material defects on the surface of transparent products, seriously affecting the appearance quality and transparency of the products. While dot injection can improve the appearance quality of products to some extent, in actual production, due to unreasonable injection point location and runner design, it is still difficult to completely avoid the generation of flow marks. In addition, traditional injection methods tend to generate high shear heat during the filling process, which further aggravates the formation of air bubbles and material defects, affecting the quality and performance of the products. Utility Model Content

[0004] (1) Technical problems to be solved

[0005] This invention provides a glue injection structure for a double-shot mold, which aims to solve the problems of defects such as air marks and material defects on the surface of the product.

[0006] (2) Technical solution

[0007] This utility model provides a gating structure for a double-shot mold, including a mold closing mechanism. The mold closing mechanism includes a front mold and a rear mold. When the mold is closed, the front mold and the rear mold surround each other to form a receiving cavity. The mold closing mechanism is provided with a main gate and a straight-through runner. The main gate is connected to the straight-through gating port of the straight-through runner.

[0008] The mold clamping mechanism is further provided with a side flow channel. The straight outlet of the straight flow channel is connected to the side inlet of the side flow channel. The side outlet of the side flow channel is connected to the receiving cavity. The outlet area S1 of the side outlet is greater than the outlet area S2 of the straight outlet.

[0009] Furthermore, the side channel includes a guide section and a glue outlet section that are interconnected. The glue outlet section has an overall fan-shaped structure, such that the glue outlet area S1 of the glue outlet section is larger than the glue inlet area S3 of the glue outlet section.

[0010] Furthermore, the guide portion includes a connecting portion and a buffer portion, and the dispensing portion is connected between the connecting portion and the buffer portion.

[0011] Furthermore, the guide section is generally C-shaped.

[0012] Furthermore, the guide section is generally S-shaped.

[0013] Furthermore, there are two receiving cavities, and the direct current channel is connected to the side flow channel corresponding to the two receiving cavities respectively.

[0014] Furthermore, the DC channel includes a main channel and a first secondary channel and a second secondary channel respectively connected to the main channel, and the first secondary channel and the second secondary channel are connected to the two side channels in a one-to-one correspondence.

[0015] Furthermore, the first secondary flow channel includes a secondary flow channel one and a secondary flow channel two that are perpendicular to each other, and the second secondary flow channel includes a secondary flow channel three and a secondary flow channel four that are perpendicular to each other and connected to each other. The main flow channel is perpendicularly connected to the secondary flow channel one and the secondary flow channel three.

[0016] Furthermore, the second and fourth secondary flow channels are integrally shaped like an inverted trumpet.

[0017] Furthermore, the side channel is connected to the receiving cavity and injection molded to form a product, the product being a transparent PC material.

[0018] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0019] By switching between point injection and large gate injection, combined with "C"-shaped side runner and fan-shaped injection design, the appearance defects caused by improper injection method in double-shot transparent products, such as air marks and material spots, are solved. At the same time, the melt flow path and shear heat distribution are optimized to reduce melt turbulence, eliminate "snake" flow marks and scorching defects, meet the stringent appearance requirements of high transparency products, and extend mold life. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of this utility model.

[0021] Figure 2 This is a schematic diagram of the DC channel connection of this utility model.

[0022] Figure 3 This is a side sectional view of the present invention.

[0023] Figure 4 This is a front sectional view of the present invention.

[0024] Figure 5This is a schematic diagram of the direct current channel and side flow channel structure of this utility model.

[0025] Figure 6 This is a schematic diagram of the DC channel structure of this utility model.

[0026] Figure 7 This invention relates to a "C"-shaped side flow channel.

[0027] Figure 8 This is the "S"-shaped side flow channel of this utility model.

[0028] Reference numerals: 1-Front mold, 2-Rear mold, 3-Receiving cavity, 4-Main runner, 41-Main runner, 412-Exit port, 42-First secondary runner, 421-Secondary runner one, 422-Secondary runner two, 43-Secondary runner two, 431-Secondary runner three, 432-Secondary runner four, 44-Straight inlet gate, 45-Straight outlet gate, 5-Product, 6-Mold closing mechanism, 61-Main gate, 62-Side runner, 621-Side inlet gate, 622-Side outlet gate, 623-Guide section, 624-Exit section, 625-Connecting section, 626-Buffer section. Detailed Implementation

[0029] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0030] like Figure 1-8 As shown, this utility model provides a gating structure for a double-shot mold, including a mold closing mechanism 6. The mold closing mechanism 6 includes a front mold 1 and a rear mold 2. When the mold is closed, the front mold 1 and the rear mold 2 enclose each other to form a receiving cavity 3. The mold closing mechanism 6 is provided with a main gate 61 and a straight-through channel 4. The main gate 61 is connected to the straight-through gating port 44 of the straight-through channel 4.

[0031] The mold clamping mechanism 6 is further provided with a side runner 62. The direct outlet 45 of the main gate 4 is connected to the side inlet 621 of the side runner 62, and the side outlet 622 of the side runner 62 is connected to the receiving cavity 3. The outlet area S1 of the side outlet 622 is larger than the outlet area S2 of the direct outlet 45. In use, the injection material is injected from the main gate 61. The molten plastic flows from the main gate 61 through the main gate 4, which transmits the molten plastic to the side runner 62 of the receiving cavity 3. The side runner 62 injects the material obtained from the main gate 41 into the receiving cavity 3 to form product 5. Product 5 is made of transparent PC material. Injection molding is performed by switching from point injection to large gate injection. Because the cross-sectional area of ​​the point injection gate is small, a large pressure loss will occur when the plastic melt passes through, resulting in insufficient filling of product 5. In addition, because the gate is small, the flow rate of the plastic melt is fast during injection, which easily causes damage to the surface of product 5. Flow marks, scorching, and black spots can form defects that hinder the injection molding of transparent materials, affecting the overall appearance of product 5. A large gate injection method allows molten plastic to flow smoothly into the mold cavity, reducing flow resistance and simplifying processing. In this invention, a large gate injection method, switching from point injection to side injection, changes the size of the gate to form a product 5 with a complete appearance and good surface. Furthermore, the gate is easier to separate from the product 5 using a large gate injection method; it can be easily removed by an ejector mechanism or manually. Since the product 5 is made of transparent PC, a point injection followed by side injection method is used to reduce the injection pressure on the machine while ensuring the appearance of the product 5. This effectively solves the gate size problem, reduces the injection pressure on the machine, increases the mold's lifespan, and avoids adverse effects such as deformation or insufficient glue caused by in-mold injection.

[0032] Furthermore, such as Figure 3-5As shown, since the side-injection method is used directly, the side outlet 622 is located on the side and connects with the receiving cavity 3 to form product 5. This may lead to uneven stress distribution inside product 5, which can easily cause defects such as warping and deformation, and also cause adverse effects such as air marks and material defects on the surface of product 5. Therefore, the side channel 62 includes a guide section 623 and an outlet section 624 that are interconnected. The outlet section 624 has a fan-shaped structure, so that the outlet area S1 of the outlet section 624 is larger than the injection area S3 of the outlet section 624. By setting the outlet section 624 with a fan-shaped structure, and the cross-sectional area of ​​the fan-shaped structure of the outlet section 624 gradually expands, the direct flow of melt is avoided, and the flow of glue is changed from concentrated flow to dispersed flow, effectively covering a larger area of ​​the cavity, reducing the local pressure caused by concentrated impact of glue, and preventing flash or burrs. At the same time, the enlarged design of the fan-shaped side outlet 622 reduces the flow rate of glue, alleviates the accumulation of shear stress, and thus reduces the internal stress concentration caused by uneven material cooling and shrinkage.

[0033] Furthermore, such as Figure 5 and Figure 7 As shown, since the product 5 to be injection molded is made of transparent PC material, the high-speed flow of the melt in the flow channel will generate high shear stress. This high shear stress can easily cause birefringence, thus affecting transparency. Therefore, in this embodiment, the flow guide 623 is generally C-shaped, including a connecting part 625 and a buffer part 626. The glue outlet 624 connects the connecting part 625 and the buffer part 626. By designing the C-shaped flow channel and the gradually expanding structure of the fan-shaped side glue outlet 622, the flow rate of the glue is reduced, and the flow rate is controlled below the critical shear rate. This reduces the shear heat and air bubble entrainment caused by high-speed flow, thereby avoiding surface defects such as air bubbles and material spots. The fan-shaped gate has a large connection area with the product 5, but is relatively thin. It can be easily removed by the ejection mechanism or manually, reducing post-processing costs and avoiding the flow marks that easily form on the surface due to the high flow rate of traditional point-injection. At the same time, the design of the buffer part 626 reduces the instantaneous fluctuation of the glue pressure, balances the glue flow rate, and ensures a uniform and continuous filling process. The buffer part 626 also extends the residence time of the glue, and in conjunction with the mold's temperature control system, homogenizes the temperature distribution, preventing material discoloration or embrittlement. It also reduces runner resistance, lowers injection pressure, reduces mechanical stress on the machine and mold, and the stable glue flow reduces erosion of the runner walls, extending the mold's service life.

[0034] Furthermore, such as Figure 8As shown, the flow guide 623 can also be designed in an "S" shape. By designing the shape of the flow guide 623, the influence of the flow rate on the product 5 can be further changed. Multiple curved sections can be designed to reduce flow resistance and turbulence, thereby improving the stability of injection molding and the quality of the product 5. At the same time, it helps to improve the venting performance of the mold, reduce defects caused by poor venting, such as bubbles and silver streaks, and improve the appearance quality of the product 5.

[0035] Specifically, the main flow channel 4 is perpendicular to the side flow channel 62. After the plastic melt enters the mold from the injection nozzle through the main gate 61, it enters the side flow channel 62 through the main flow channel 4. Since the two are perpendicular, the flow direction of the melt changes by 90 degrees, allowing the melt to better adapt to the complex structure and cavity layout inside the mold. The melt flows at high speed in the main flow channel 4, and when it enters the side flow channel 62, the flow speed will decrease due to the change in direction. This helps to reduce the shear heat of the melt during the flow process and avoid problems such as melt degradation caused by excessive shear heat. Since the speed of the melt decreases when it enters the side flow channel 62, the impact force on the mold cavity is reduced, thereby extending the service life of the mold.

[0036] Furthermore, such as Figure 6-7 As shown, the main flow channel 4 includes a main flow channel 41 and a first secondary flow channel 42 and a second secondary flow channel 43 connected to the main flow channel 41. The first secondary flow channel 42 and the second secondary flow channel 43 are connected to the two side flow channels 62 in a one-to-one correspondence. Furthermore, the first secondary flow channel 42 includes a first secondary flow channel 421 and a second secondary flow channel 422 that are perpendicular to each other, and the second secondary flow channel 43 includes a third secondary flow channel 431 and a fourth secondary flow channel 432 that are perpendicular to each other. The main flow channel 41 is perpendicularly connected to the first secondary flow channel 421 and the third secondary flow channel 431. In this embodiment, two identical and mutually isolated receiving cavities 3 are formed between the front mold 1 and the rear mold 2 to form two identical products 5. The main flow channel 4 is connected to the side flow channels 62 corresponding to the two receiving cavities 3 respectively, so that the material from the main flow channel 41 flows through the two flow channels to achieve split injection molding, which further improves injection molding efficiency and saves costs.

[0037] By dividing the melt into two runners, two identical products 5 can be injection molded simultaneously in two cavities, significantly improving production efficiency and shortening the production cycle. This effectively reduces the production cost per unit product 5. The main runner 41 evenly distributes material to the first secondary runner 42 and the second secondary runner 43. This design simplifies the mold structure, reduces mold complexity and manufacturing costs. Uniform material distribution and injection pressure reduce mold wear and extend mold life. Precise material distribution reduces material residence time in the runners, minimizing material waste. Simultaneous production of multiple products 5 significantly reduces the production cost per unit product 5, improving the company's economic benefits. This design can be adjusted according to different product 5 requirements, such as changing the size and shape of the secondary runners to accommodate products of different shapes and sizes. By adjusting the design of the main runner 41 and secondary runners, injection parameters such as injection speed and pressure can be optimized, further improving product quality and production efficiency.

[0038] Furthermore, the ends of the secondary runner 422 and the secondary runner 432 are inverted trumpet-shaped structures, which can reduce the flow resistance of the material when entering the side runner 62, allowing the material to fill the cavity more smoothly and reducing defects caused by flow resistance; it also helps to improve the venting performance of the mold and reduce defects caused by poor venting, such as bubbles and silver streaks; by reducing flow resistance and improving venting performance, the quality and appearance of product 5 can be improved and defects can be reduced.

[0039] Specifically, such as Figure 6 As shown, the diameter R1 of the straight inlet gate 44 of the main runner 41 is smaller than the diameter R2 of the outlet gate 412. The smaller diameter of the straight inlet gate 44 can increase the flow rate of the melt material, allowing the material to enter the mold more quickly through the straight inlet gate 44. This helps to improve injection molding efficiency and shorten the production cycle. At the same time, the smaller diameter of the straight inlet gate 44 reduces the flow resistance of the material when entering the mold, allowing the material to fill more smoothly. The smaller diameter of the straight inlet gate 44 can reduce the impact force of the material on the mold, reduce mold wear, and thus improve the service life of the mold.

[0040] The following is a detailed explanation of the working principle of this utility model;

[0041] In use, the injection material is injected from the main gate 61, and the glue flows from the main gate 61 through the direct flow channel 4. The direct flow channel 4 transmits the glue to the side flow channel 62. The side outlet 622 of the side flow channel 62 is designed in the shape of a fan. The side flow channel 62 injects the material obtained from the direct flow channel 4 into the receiving cavity 3 through the fan-shaped side outlet 622 to form the product 5.

[0042] The innovation of this utility model lies in the switching between point injection and large gate injection, combined with the "C"-shaped side runner and fan-shaped injection design, to solve the appearance defects caused by improper injection method in double-shot transparent products, such as air marks and material spots. At the same time, it optimizes the melt flow path and shear heat distribution, reduces melt turbulence, eliminates "snake-like" flow marks and scorching defects, meets the stringent appearance requirements of high transparency products, and extends mold life.

[0043] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

[0044] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A glue injection structure for a double-shot mold, characterized in that, The mold includes a mold closing mechanism (6), which includes a front mold (1) and a rear mold (2). When the mold is closed, the front mold (1) and the rear mold (2) enclose each other to form a receiving cavity (3). The mold closing mechanism (6) is provided with a main gate (61) and a direct flow channel (4). The main gate (61) is connected to the direct inlet gate (44) of the direct flow channel (4). The mold closing mechanism (6) is also provided with a side flow channel (62). The straight outlet (45) of the straight channel (4) is connected to the side inlet (621) of the side flow channel (62). The side outlet (622) of the side flow channel (62) is connected to the receiving cavity (3). The outlet area S1 of the side outlet (622) is greater than the outlet area S2 of the straight outlet (45).

2. The injection structure of a double-shot mold according to claim 1, characterized in that, The side channel (62) includes a guide section (623) and a glue outlet section (624) that are interconnected. The glue outlet section (624) has an overall fan-shaped structure, so that the glue outlet area S1 of the glue outlet section (624) is larger than the glue inlet area S3 of the glue outlet section (624).

3. The injection structure of a double-shot mold according to claim 2, characterized in that, The guide section (623) includes a connecting section (625) and a buffer section (626), and the dispensing section (624) is connected between the connecting section (625) and the buffer section (626).

4. The injection structure of a double-shot mold according to claim 3, characterized in that, The guide section (623) is C-shaped in general.

5. The injection structure of a double-shot mold according to claim 3, characterized in that, The guide section (623) is generally S-shaped.

6. The injection structure of a double-shot mold according to claim 1, characterized in that, There are two accommodating cavities (3), and the direct current channel (4) is connected to the side flow channel (62) corresponding to the two accommodating cavities (3).

7. The injection structure of a double-shot mold according to claim 5, characterized in that, The DC channel (4) includes a main channel (41) and a first secondary channel (42) and a second secondary channel (43) respectively connected to the main channel (41). The first secondary channel (42) and the second secondary channel (43) are connected to the two side channels (62) in a one-to-one correspondence.

8. The injection structure of a double-shot mold according to claim 7, characterized in that, The first secondary flow channel (42) includes a secondary flow channel one (421) and a secondary flow channel two (422) that are perpendicular to each other, and the second secondary flow channel (43) includes a secondary flow channel three (431) and a secondary flow channel four (432) that are perpendicular to each other. The main flow channel (41) is perpendicularly connected to the secondary flow channel one (421) and the secondary flow channel three (431).

9. The injection structure of a double-shot mold according to claim 8, characterized in that, The secondary flow channel two (422) and the secondary flow channel four (432) are in the shape of an inverted trumpet.

10. The injection structure of a double-shot mold according to claim 1, characterized in that, The side channel (62) is connected to the receiving cavity (3) to form a product (5) by injection molding, and the product (5) is made of PC transparent material.

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