Injection molding body and injection mold

Abstract

The utility model relates to the technical field of injection molding, in particular to an injection molding body and an injection mold. The injection molding body comprises a primary molding body and a secondary molding body, the primary molding body is provided with a combination surface used for being combined with the secondary molding body, an exhaust hole is formed in the combination surface, and the exhaust hole is a through hole penetrating through the primary molding body. And the secondary forming body is fixedly connected with the primary forming body through the combination surface. According to the injection molding body and the injection mold, the one-time molding body is formed in the injection mold at one time, gas can be exhausted through the exhaust insert in the one-time molding process, and the formed one-time molding body is provided with the exhaust hole; when the secondary forming body is formed on the basis of the primary forming body, air can be exhausted through the exhaust hole and the exhaust insert in sequence, air trapping is not prone to occurring between the secondary forming body and the primary forming body, and a finally-formed product is not prone to bulging.

Description

Technical Field

[0001] The utility model relates to the technical field of injection molding, in particular to an injection molding body and an injection mold. Background Art

[0002] Two-color injection molding is a special injection molding technology that allows products with two or more colors or materials to be produced through two injection molding processes in the same mold. This technology can significantly improve the visual appeal and functionality of the product during the manufacturing process while reducing assembly steps and costs.

[0003] In the traditional two-shot molding process, a primary injection molding process creates a preliminary molded part. Subsequently, a secondary injection molding process is performed based on this molded part to add parts of different colors or materials. During this secondary molding process, the gas between the secondary and primary molded parts may not be exhausted in time, resulting in bulging in the final product, seriously affecting the product's appearance quality and physical properties. Utility Model Content

[0004] The utility model mainly solves the problem of bulging in products formed by double-color injection molding.

[0005] According to the first aspect, an embodiment provides an injection molded body, comprising: a primary molded body and a secondary molded body, the primary molded body having a bonding surface for bonding with the secondary molded body, an exhaust hole being provided on the bonding surface, and the exhaust hole being a through hole passing through the primary molded body, the secondary molded body being fixedly connected to the primary molded body via the bonding surface.

[0006] In some embodiments, the secondary molded body includes a base and a fixing portion, the fixing portion is located on a side of the base close to the primary molded body, and the fixing portion is formed in the exhaust hole.

[0007] In some embodiments, at least two exhaust holes are provided, and at least two exhaust holes are arranged at intervals on the bonding surface.

[0008] In some embodiments, the axis of the exhaust hole is perpendicular to the bonding surface.

[0009] In some embodiments, an exhaust groove is provided on the edge of the joint surface.

[0010] In some embodiments, one of the primary molded body and the secondary molded body is provided with a groove, and the other is provided with a protrusion adapted to the groove, and the protrusion is embedded in the groove.

[0011] In some embodiments, a plurality of the exhaust holes are provided, and the plurality of the exhaust holes are arranged in a rectangular array on the bonding surface.

[0012] In some embodiments, the hardness of the material of the primary molded body is greater than the hardness of the material of the secondary molded body.

[0013] According to the second aspect, an embodiment provides an injection mold for molding the injection-molded body described in any of the above embodiments, comprising a lower mold, an upper mold and an exhaust insert, a molding cavity is formed between the lower mold and the upper mold, the exhaust insert is embedded in the lower mold, and is used to discharge the gas discharged from the exhaust hole from the molding cavity.

[0014] In some embodiments, the exhaust insert is provided with a main channel and a plurality of branch channels, the plurality of branch channels are all connected to the main channel, and the plurality of branch channels are located at the lower side of the exhaust hole and are used to communicate with the exhaust hole.

[0015] According to the injection molded body and injection mold of the above embodiment, the primary molded body is molded once in the injection mold, and the gas can be discharged through the exhaust insert during the primary molding process, and the primary molded body after molding has exhaust holes; when the secondary molded body is molded on the basis of the primary molded body, the gas can be discharged through the exhaust holes and the exhaust insert in sequence, and it is not easy for air to be trapped between the secondary molded body and the primary molded body, and the final molded product is not prone to bulging. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic structural diagram of an embodiment of the injection molded body of the utility model;

[0017] Figure 2 for Figure 1 Schematic diagram of the molding process of the injection molded body;

[0018] Figure 3 for Figure 1 A front view of a primary molded body of an injection molded body;

[0019] Figure 4 for Figure 1 A reverse side view of a primary molded body of an injection molded body;

[0020] Figure 5 for Figure 1 A front view of a secondary molded body of an injection molded body;

[0021] Figure 6 for Figure 1 A reverse side view of a secondary molded body of an injection molded body;

[0022] Reference numerals:

[0023] 1. Primary molded body; 11. Joint surface; 12. Exhaust hole; 13. Exhaust groove; 14. Groove; 2. Secondary molded body; 21. Base; 22. Fixing portion; 23. Protrusion; 3. Exhaust insert; 31. Main channel; 31. Branch channel. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below by means of specific embodiments in conjunction with the accompanying drawings. Similar elements in different embodiments are numbered with associated similar elements. In the following embodiments, many detailed descriptions are provided to enable the present application to be better understood. However, those skilled in the art will readily appreciate that some of the features may be omitted under different circumstances, or may be replaced by other elements, materials, or methods. In some cases, some operations related to the present application are not shown or described in the specification. This is to avoid the core portion of the present application being overwhelmed by excessive descriptions. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and the general technical knowledge in the art.

[0025] In addition, the features, operations, or characteristics described in the specification may be combined in any appropriate manner to form various embodiments. Furthermore, the steps or actions in the method description may be reordered or adjusted in a manner readily apparent to those skilled in the art. Therefore, the various sequences in the specification and drawings are provided solely for the purpose of clearly describing a particular embodiment and are not intended to be mandatory, unless otherwise specified.

[0026] The serial numbers assigned to components herein, such as "first," "second," etc., are used solely to distinguish the objects being described and do not convey any sequential or technical meaning. References to "connection" and "coupling" herein, unless otherwise specified, include both direct and indirect connections (couplings).

[0027] Two-color products are typically molded using two-shot injection molding. During this process, after the first shot of hard plastic molding, gas cannot be exhausted during the second shot of soft plastic molding, which can easily lead to bulging, especially when the hard and soft plastic bonding area is large. To address this bulging issue, vent holes can be added to the primary molded part during product design. This allows gas to escape through the vent holes during the second shot, reducing bulging.

[0028] Please refer to Figure 1-Figure 4In one embodiment, an injection molded body is provided, which includes a primary molded body 1 and a secondary molded body 2. The primary molded body 1 is formed by first injecting material into the mold for a single injection molding, and the secondary molded body 2 is formed by injecting material into the mold again for a secondary injection molding on the basis of the primary molded body 1 after the primary molded body 1 is formed.

[0029] The primary molded body 1 has a bonding surface 11 for bonding with the secondary molded body 2. In this embodiment, the primary molded body 1 is located on the lower side of the secondary molded body 2, that is, the upper surface of the primary molded body 1 serves as the bonding surface 11, and the secondary molded body 2 is fixedly connected to the primary molded body 1 via the bonding surface 11. A vent 12 is provided on the bonding surface 11, and the vent 12 is a through hole that passes through the primary molded body 1. Specifically, the vent 12 is formed during the primary injection molding process. For example, it can be formed by providing a corresponding core-pulling structure in the upper or lower mold of the injection mold.

[0030] The primary molded body 1 is formed in a single step in the injection mold. During the primary molding process, gas can be discharged through the vent insert 3. After molding, the primary molded body 1 has vent holes 12. When the secondary molded body 2 is molded based on the primary molded body 1, gas can be discharged through the vent holes 12 and the vent insert 3. This reduces the risk of gas being trapped between the secondary molded body 2 and the primary molded body 1, and the resulting molded product is less likely to bulge.

[0031] In some embodiments, please refer to Figure 5 and Figure 6 The secondary molded body 2 includes a base 21 and a fixing portion 22. The fixing portion 22 is located on a side of the base 21 close to the primary molded body 1 and is formed in the exhaust hole 12. The secondary molded body 2 is formed by secondary injection molding based on the primary molded body 1.

[0032] During secondary injection molding, material is injected into the mold. During the material flow process, gas in the mold can be discharged through the vent holes 12 and the vent insert 3 provided on the mold. As the gas is discharged, the material can flow into the vent holes 12 and be formed in the vent holes 12. The portion formed in the vent holes 12 is the fixed portion 22 of the secondary molded body 2. The provision of the vent holes 12 not only allows gas to be discharged and solves the bulging problem caused by trapped gas, but the fixed portion 22 formed in the vent holes 12 also improves the bonding strength between the primary molded body 1 and the secondary molded body 2.

[0033] In some embodiments, please refer to Figure 3 and Figure 4 At least two vent holes 12 are provided, and the at least two vent holes 12 are spaced apart on the bonding surface 11. During secondary injection molding, the multiple vent holes 12 can promptly discharge the gas in the mold, and the gas is discharged more fully, so that the final injection molded body is less likely to bulge, which is conducive to improving the product yield.

[0034] The number of the exhaust holes 12 and the size of each exhaust hole 12 can be specifically determined according to the combined area of ​​the primary molded body 1 and the secondary molded body 2, so as to timely exhaust the gas in the injection mold during the secondary injection molding process.

[0035] In some embodiments, please refer to Figure 3 and Figure 4 A plurality of vent holes 12 are provided, and the plurality of vent holes 12 are arranged in a rectangular array on the bonding surface 11. Specifically, the plurality of vent holes 12 can be evenly distributed in a rectangular array on the bonding surface 11. Providing multiple vent holes 12 can promptly discharge gas from the injection mold. Furthermore, the fixing portions 22 formed in the vent holes 12 during the secondary injection molding process can also enhance the bonding strength between the primary molded body 1 and the secondary molded body 2.

[0036] In other embodiments, the exhaust holes 12 may also be arranged in a circular array or randomly on the bonding surface 11 .

[0037] In some embodiments, please refer to Figure 3 and Figure 4 The axis of the vent hole 12 is perpendicular to the joint surface 11. To achieve the exhaust function, the vent hole 12 needs to penetrate the entire primary molded body 1. Setting it perpendicular to the joint surface 11 helps to reduce the hole depth, shorten the gas path, and facilitate timely exhaust of gas in the mold during the injection molding process. In addition, the vent hole 12 perpendicular to the joint surface 11 has a simpler structure and can be formed using a simple core-pulling structure.

[0038] In some embodiments, please refer to Figure 3 and Figure 4 The edge of the joint surface 11 is provided with an exhaust groove 13. Specifically, the exhaust groove 13 can be provided along the thickness direction of the primary molded body 1. The exhaust groove 13 has a similar function to the exhaust hole 12 and is used to discharge the gas in the injection mold during the injection molding process.

[0039] In some embodiments, please refer to Figure 3-Figure 6 , one of the primary molded body 1 and the secondary molded body 2 is provided with a groove 14, and the other is provided with a protrusion 23 adapted to the groove 14, and the protrusion 23 is embedded in the groove 14. In this embodiment, the primary molded body 1 is provided with a groove 14, which is arranged obliquely on the bonding surface 11, and the secondary molded body 2 is provided with a protrusion 23 adapted to the groove 14. The provision of the groove 14 and the protrusion 23 can increase the bonding surface 11 area of ​​the primary molded body 1 and the secondary molded body 2, and enhance the bonding force between the primary molded body 1 and the secondary molded body 2.

[0040] In some embodiments, the primary molded body 1 is made of a harder material than the secondary molded body 2. In this embodiment, the primary molded body 1 can be made of a hard plastic such as polypropylene, polyethylene, polycarbonate, or ABS resin; the secondary molded body 2 can be made of a soft plastic such as thermoplastic elastomer, silicone rubber, or polyurethane. The primary molded body 1 has a greater hardness, providing greater rigidity and stability, and can provide stable support for the soft plastic.

[0041] According to a second aspect, an embodiment provides an injection mold for molding the injection-molded body according to any one of the above embodiments.

[0042] Please refer to Figure 1 The injection mold includes a lower mold (not shown), an upper mold (not shown), and a vent insert 3. A molding cavity is formed between the lower and upper molds, and is used to form the primary molded body 1 and the secondary molded body 2, respectively. The vent insert 3 is embedded in the lower mold and is used to discharge gas exhausted from the vent hole 12 from the molding cavity.

[0043] In some embodiments, please refer to Figure 1 The exhaust insert 3 is provided with a main channel 31 and multiple branch channels 31. The multiple branch channels 31 are all connected to the main channel 31. The multiple branch channels 31 are located below the exhaust hole 12 and are used to communicate with the exhaust hole 12. Specifically, the multiple branch channels 31 are evenly distributed below the primary molded body 1 and are connected to the exhaust hole 12 on the primary molded body 1, which can promptly discharge the gas in the injection mold during the injection molding process.

[0044] The process of molding the injection molded body of the present invention in the injection mold is as follows.

[0045] First, the first material is injected into the lower mold, forming a primary molded body 1 in the injection mold. During the primary injection molding process, gas can be discharged through the vent insert 3, and the primary molded body 1 after molding has vent holes 12. Then, a secondary injection molding is performed on the primary molded body 1. During the secondary injection molding, the second material is injected into the lower mold. During this process, gas can be discharged through the vent holes 12 and the vent insert 3. At the same time, some of the second material flows into the vent hole 12 and is molded there. After two injection moldings, the final injection molded body is formed.

[0046] The above examples are used to illustrate the present invention, which are only used to help understand the present invention and are not intended to limit the present invention. Those skilled in the art of the present invention can make some simple deductions, modifications or substitutions based on the concept of the present invention.

Claims

1. An injection molded body, characterized in that include: A primary molded body and a secondary molded body, wherein the primary molded body has a bonding surface for bonding with the secondary molded body, the bonding surface is provided with an exhaust hole, and the exhaust hole is a through hole that penetrates the primary molded body, and the secondary molded body is fixedly connected to the primary molded body through the bonding surface.

2. The injection molded article according to claim 1, wherein The secondary molded body includes a base and a fixing portion. The fixing portion is located on a side of the base close to the primary molded body, and the fixing portion is formed in the exhaust hole.

3. The injection molded article according to claim 1, wherein At least two exhaust holes are provided, and at least two exhaust holes are arranged at intervals on the bonding surface.

4. The injection molded article according to claim 1, wherein The axis of the exhaust hole is perpendicular to the joint surface.

5. The injection molded article according to claim 1, wherein An exhaust groove is provided on the edge of the joint surface.

6. The injection molded article according to claim 1, wherein One of the primary molded body and the secondary molded body is provided with a groove, and the other is provided with a protrusion adapted to the groove, and the protrusion is embedded in the groove.

7. The injection molded article according to claim 6, wherein There are multiple exhaust holes, and the multiple exhaust holes are arranged in a rectangular array on the bonding surface.

8. The injection molded article according to claim 6, wherein The material hardness of the primary molded body is greater than the material hardness of the secondary molded body.

9. An injection mold for molding the injection molded body according to any one of claims 1 to 8, characterized in that: The mold comprises a lower mold, an upper mold and an exhaust insert. A molding cavity is formed between the lower mold and the upper mold. The exhaust insert is embedded in the lower mold and is used to exhaust the gas exhausted from the exhaust hole from the molding cavity.

10. The injection mold according to claim 9, characterized in that The exhaust insert is provided with a main channel and a plurality of branch channels, the plurality of branch channels are all communicated with the main channel, and the plurality of branch channels are located at the lower side of the exhaust hole and are used to communicate with the exhaust hole.

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