A method for manufacturing a metal-plastic composite structure and a shell product

Abstract

This invention provides a method for manufacturing a metal-plastic composite structure and a shell product, including: S1, a metal shell frame manufactured by 3D printing, with an annular groove formed in the inner periphery of the metal shell frame, and several anchor points recessed at the bottom of the annular groove; S2, placing the metal shell frame into an injection molding machine and fixing it, then performing an injection molding operation; S3, opening the injection molding machine and removing the finished product, the metal-plastic composite shell is formed, and the plastic frame is attached to the inner periphery of the metal shell frame, so that the anchor points are filled with plastic anchor points to form bonding tensile strength points. This invention uses a specific insert structure formed by additive manufacturing at the interface between the metal and plastic, and utilizes the insert body structure being larger than the inlet to form a limiting snap-fit, so that when the composite structure is subjected to tensile or shear forces, the snap-fit ​​structure of the specific insert achieves a tight fit, effectively preventing cracking of the metal-plastic bonding surface, improving waterproof performance, and increasing connection strength.

Description

Technical Field

[0001] This invention belongs to the field of injection molding technology and relates to a multi-material bonding method, particularly a method for manufacturing a metal-plastic composite structure and a shell product. Background Technology

[0002] With the development of technology, people have increasingly sophisticated requirements for the casings of electronic products. They need both an aesthetically pleasing design and multiple functions. Since electronic products generate heat during use, metal casings are used to facilitate heat dissipation. However, waterproofing is also required, necessitating the addition of a plastic structure inside the casing for sealing. However, current technology simply uses a flat bonding between the plastic and metal structures, which leads to cracking between the metal and plastic, resulting in poor waterproofing and material waste.

[0003] To address the aforementioned technical problems, for example, Chinese patent literature has disclosed a bonding structure between an electronic product casing and a plastic part [Chinese Patent No.: 201210178334.9]. This invention discloses a bonding structure between an electronic product casing and a plastic part, including a casing substrate with a groove on it. A plastic part is injection molded into the groove, and the plastic part covers the groove. The casing substrate is one of metal, metal composite material, and non-metallic composite material. The groove is one of circular hole, square hole, and serrated shape. This invention can effectively achieve the bonding between the electronic product casing and the plastic part, especially better achieving the bonding between carbon fiber or glass fiber composite material casings and complex structural parts. This composite material casing not only retains the advantages of composite materials such as good radiation protection, high strength, thinness, light weight, corrosion resistance, high temperature resistance, and aesthetics, but also creates a plastic part with a complex structure through hole-shaped grooves or serrated grooves and insert injection molding process. Furthermore, the bonding between the plastic part and the electronic product casing is more stable after molding and bonding.

[0004] Although the above technical solution uses a groove to fit the plastic body, the fitting structure fails to form a locking and limiting mechanism, thus there is still a risk of separation between the plastic body and the metal body. Further strengthening of the composite structure of the plastic body and the metal body is required. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a method for manufacturing a metal-plastic composite structure and a shell product that utilizes an internal cavity structure larger than the opening diameter to form a limiting snap-fit, and combines this with an effective injection molding process to enhance the connection strength between different materials.

[0006] The objective of this invention can be achieved through the following technical solution: A method for manufacturing a metal-plastic composite structure, comprising the following steps:

[0007] S1. A metal outer shell frame is manufactured using 3D printing. An annular groove is formed by recessing the inner periphery of the metal outer shell frame. Several anchor points are recessed at the bottom of the annular groove. Specifically, the anchor points are variable diameter cavities, and the inner diameter of the variable diameter cavity is larger than the diameter of the cavity opening. Several nanopores are opened on the bottom edge of the variable diameter cavity through T processing.

[0008] S2. Place the metal outer frame into the injection molding equipment and fix it in place, ready for injection molding operation;

[0009] (1) Dry the injection molding raw materials;

[0010] (2) Set the barrel temperature;

[0011] (3) Set the mold temperature;

[0012] (4) Open multiple valve needles of the injection molding equipment in sequence to inject injection molding material into the metal outer frame in turn;

[0013] S3. Open the injection molding equipment and take out the finished product. The metal-plastic composite shell is formed. The plastic frame is attached to the inner periphery of the metal shell frame, so that the anchor points are filled with plastic anchor points to form a bonding tensile point.

[0014] In the above-mentioned method for manufacturing metal-plastic composite structures, in step S2, the injection molding equipment is specifically a 250T injection molding machine, and the total injection cycle is 65-70 seconds.

[0015] In the above-mentioned method for manufacturing metal-plastic composite structures, in step S2(1), a desiccant is used to dry the injection molding raw material, the drying temperature is 100-120℃, and the drying time is 3.5-4H.

[0016] In the above-mentioned method for manufacturing metal-plastic composite structure, in step S1(2), the temperature of the feed port is 80-90℃, and the temperature of the barrel and the hot runner is 250-270℃; in step S1(3), the temperature of the mold is 145-165℃.

[0017] In the above-mentioned method for manufacturing metal-plastic composite structures, in step S2(4), the injection speed is 50-200 mm / s, the injection time is 0.66-0.68 s, and the injection equipment pressure is 2400-2600 kg / cm². 2 ;

[0018] The holding speed is 45–55 mm / s, and the holding pressure is 2000–2200 kg / cm². 2 The holding time is 15–20 seconds, and the cooling time is 13–20 seconds; the maximum injection pressure does not exceed 2800 kg / cm². 2 .

[0019] In the above-mentioned method for manufacturing a metal-plastic composite structure, the metal outer shell is made of any one of titanium alloy, aluminum alloy, or stainless steel; the plastic frame is made of one or at least two of polyphenylene sulfide, polybutylene terephthalate, high-density polyethylene, polycarbonate, and acrylonitrile-butadiene-styrene copolymer.

[0020] A housing product, obtained by the method described above for manufacturing a metal-plastic composite structure.

[0021] The aforementioned housing product includes a metal outer shell frame. The inner periphery of the metal outer shell frame is recessed with an annular groove. The bottom of the annular groove is recessed with several anchor points. Each anchor point has a locking opening. A plastic frame is attached inside the annular groove. The bottom surface of the plastic frame is integrally fixed with several anchor point protrusions that fill the anchor point protrusions. The anchor point protrusions are locked into the locking openings.

[0022] In the aforementioned shell product, the anchor point cavity is a T-shaped cavity, the end of the vertical rod cavity of the T-shaped cavity forms the locking opening, and the horizontal rod cavity of the T-shaped cavity forms the inner cavity structure; the anchor point protrusion is a T-shaped protrusion, the length of the horizontal rod of the T-shaped protrusion is greater than the width of the end of the vertical rod, and the right angle inflection point between the horizontal rod and the vertical rod forms the locking point.

[0023] In the aforementioned shell product, the anchor point cavity is a bottle-shaped cavity, the top of the bottle-shaped cavity forms the locking opening, the bottle-shaped cavity gradually expands downwards in an arc to form an inner cavity structure, the anchor point protrusion is a bottle-shaped protrusion, the diameter of the lower arc of the bottle-shaped protrusion is larger than the diameter of the upper bottleneck, and the arc inflection point between the lower arc and the upper bottle diameter forms a locking point.

[0024] Compared with existing technologies, the manufacturing method of this metal-plastic composite structure and the resulting shell product have the following advantages:

[0025] 1. A specific insert structure formed by additive manufacturing is used to bond the metal and plastic at the interface. The main structure of the insert is larger than the inlet to form a limiting snap-fit. When the composite structure is subjected to tensile or shear forces, the snap-fit ​​structure of the specific insert achieves a tight fit, effectively preventing cracking of the metal and plastic bonding surface, improving waterproof performance, and increasing connection strength.

[0026] 2. Patterns are created on the bonding surfaces of the metal and plastic to form a rough surface, thereby improving the bonding strength between the plastic and the metal after the injection molding process.

[0027] 3. The 3D printed metal substrate and special insert structure are integrated into a single part. On the metal side, except for the mating surface, the appearance of the rest of the parts remains smooth, ensuring that the overall shape of the metal-plastic composite part forms a smooth straight line or curve, enhancing the overall aesthetics.

[0028] 4. Adopt reasonable injection molding process conditions and a step-by-step injection sequence to optimize the injection molding process, improve the bonding effect between plastic and metal composite structures, and improve the yield and quality of finished products. Attached Figure Description

[0029] Figure 1 This is a three-dimensional structural diagram of the metal-plastic composite structure.

[0030] Figure 2 This is an anchor point structure diagram of Embodiment 2 of this metal-plastic composite structure.

[0031] Figure 3 This is an enlarged structural diagram of the anchor point in Embodiment 2 of this metal-plastic composite structure.

[0032] Figure 4 This is an anchor point structure diagram of Embodiment 3 of the metal-plastic composite structure.

[0033] Figure 5 This is an enlarged structural diagram of the anchor point in Embodiment 3 of this metal-plastic composite structure.

[0034] In the diagram, 1 is the metal outer frame; 2 is the plastic frame; 3 is the T-shaped protrusion; 3a is the nano protrusion one; 4 is the bottle-shaped protrusion; and 4a is the nano protrusion two. Detailed Implementation

[0035] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0036] Example 1

[0037] A method for manufacturing a metal-plastic composite structure includes the following steps:

[0038] S1. A metal outer shell frame 1 is manufactured using 3D printing. An annular groove is formed within the inner periphery of the metal outer shell frame 1, and several anchor points are recessed at the bottom of the groove. These anchor points are specifically variable-diameter cavities, with a size at the micrometer level, and the inner diameter of the variable-diameter cavity is larger than the opening diameter. Several nanopores are created on the bottom edge of the variable-diameter cavities through a T-process. The constricted structure of the anchor points allows for a snap-fit ​​connection between the injection-molded material and the cavities after injection molding, thereby improving the bonding strength and preventing cracking or detachment.

[0039] The surface texture of the groove wall outside the anchor point area can be a matrix structure formed by protruding or recessed patterns, or a mesh structure formed by stripes.

[0040] S2. Place the metal outer frame 1 into the injection molding equipment and fix it in place, ready for injection molding operation; the injection molding equipment is a 250T injection molding machine, and the total injection cycle is 65-70 seconds.

[0041] (1) Dry the injection molding raw material; use a desiccant to dry the injection molding raw material, the drying temperature is 100~120℃, and the drying time is 3.5~4H.

[0042] (2) Set the barrel temperature: The feed port temperature is 80-90℃, and the barrel temperature and hot runner temperature are 250-270℃;

[0043] (3) Set the mold temperature: 145~165℃;

[0044] (4) Open multiple valve needles of the injection molding equipment in sequence to inject injection molding material into the metal outer frame 1 in turn;

[0045] The injection speed is 50–200 mm / s, the injection time is 0.66–0.68 s, and the injection equipment pressure is 2400–2600 kg / cm². 2 Maximum injection pressure not exceeding 2800 kg / cm² 2 .

[0046] The holding speed is 45–55 mm / s, and the holding pressure is 2000–2200 kg / cm². 2 The pressure holding time is 15-20 seconds, and the cooling time is 13-20 seconds.

[0047] S3. Open the injection molding equipment and take out the finished product. The metal-plastic composite shell is formed. The plastic frame 2 is attached to the inner circumference of the metal shell frame 1, so that the anchor point cavity is filled with plastic anchor points to form a bonding tensile point.

[0048] The metal outer frame 1 is made of, but is not limited to, one of titanium alloy, aluminum alloy, or stainless steel. The plastic frame 2 is made of, but is not limited to, one or at least two of polyphenylene sulfide (PPS), polybutylene terephthalate (PBT), high-density polyethylene (PE-HD), polycarbonate (PC), and acrylonitrile-butadiene-styrene copolymer (ABS).

[0049] Compared with existing technologies, the manufacturing method of this metal-plastic composite structure has the following advantages:

[0050] 1. A specific insert structure formed by additive manufacturing is used to bond the metal and plastic at the interface. The main structure of the insert is larger than the inlet to form a limiting snap-fit. When the composite structure is subjected to tensile or shear forces, the snap-fit ​​structure of the specific insert achieves a tight fit, effectively preventing cracking of the metal and plastic bonding surface, improving waterproof performance, and increasing connection strength.

[0051] 2. Patterns are created on the bonding surfaces of the metal and plastic to form a rough surface, thereby improving the bonding strength between the plastic and the metal after the injection molding process.

[0052] 3. The 3D printed metal substrate and special insert structure are integrated into a single part. On the metal side, except for the mating surface, the appearance of the rest of the parts remains smooth, ensuring that the overall shape of the metal-plastic composite part forms a smooth straight line or curve, enhancing the overall aesthetics.

[0053] 4. Adopt reasonable injection molding process conditions and a step-by-step injection sequence to optimize the injection molding process, improve the bonding effect between plastic and metal composite structures, and improve the yield and quality of finished products.

[0054] Example 2

[0055] Based on Embodiment 1, the difference in this embodiment is as follows:

[0056] A housing product, obtained by the method described above for manufacturing a metal-plastic composite structure.

[0057] like Figures 1 to 3 As shown, the shell product includes a metal shell frame 1. The inner periphery of the metal shell frame 1 is recessed with an annular groove. The bottom of the annular groove is recessed with several anchor points. The anchor points have locking openings. A plastic frame 2 is attached inside the annular groove. The bottom surface of the plastic frame 2 is integrally fixed with several anchor protrusions that fill the anchor points. The anchor protrusions are locked in the locking openings.

[0058] The plastic frame 2 is not only fixed to the metal outer frame 1 through the bonding surface, but also uses several anchor protrusions to be embedded in the anchor holes. The structural feature of large inner cavity and small outlet forms a limiting snap-fit, so that the metal-plastic composite structure will still be tightly bonded through the insert snap-fit ​​structure when subjected to tensile or shear force, avoiding cracking or separation.

[0059] like Figure 2 and Figure 3As shown, the anchor point is a T-shaped cavity. The end of the vertical shaft cavity of the T-shaped cavity forms a locking constriction. The horizontal shaft cavity of the T-shaped cavity forms an inner cavity structure. An additional T-processing step is added, and several nano-holes are opened on the bottom edge of the horizontal shaft of the T-shaped cavity. Plastic is injected into the T-shaped cavity and the nano-holes, so that the anchor point protrusion is a T-shaped protrusion 3 combined with several nano-protrusions 3a. The length of the horizontal shaft of the T-shaped protrusion 3 is greater than the width of the end of the vertical shaft. The right angle inflection point between the horizontal shaft and the vertical shaft forms a locking point.

[0060] By utilizing the locking points where the length of the horizontal bar is greater than the width of the vertical bar end and forms a right-angle bend, when the plastic frame 2 is subjected to external tension, the locking points provide a tensile reaction force, ensuring that the plastic frame 2 remains tightly attached to the inner frame edge of the metal outer shell 1. The anchor points are distributed in a certain pattern, but their shapes include, but are not limited to, T-shaped structures.

[0061] Tests have shown that the tensile strength of the T-shaped anchor point is 18-20 MPa.

[0062] Example 3

[0063] This embodiment is basically the same as embodiment two, except that:

[0064] like Figure 4 and Figure 5 As shown, the anchor point cavity is a bottle-shaped cavity. The top of the bottle-shaped cavity forms a locking constriction. The bottle-shaped cavity gradually expands downwards in an arc to form an inner cavity structure. A T-processing step is added, and several nanopores are opened on the arc bottom edge of the bottle-shaped cavity. Plastic is injected into the bottle-shaped cavity and the nanopores. The anchor point protrusion is a bottle-shaped protrusion 4 combined with several nano protrusions 4a. The diameter of the lower arc of the bottle-shaped protrusion 4 is larger than the diameter of the upper bottleneck. The arc inflection point between the lower arc and the upper bottle diameter forms a locking point.

[0065] By utilizing the locking points where the diameter of the lower arc is larger than the diameter of the upper bottleneck and forms an arc inflection point, when the plastic frame 2 is subjected to external tension, the locking points provide a tensile reaction force, ensuring that the plastic frame 2 remains tightly attached to the inner frame edge of the metal outer shell 1. The anchor points are distributed in a certain pattern, but their shapes include, but are not limited to, bottle-shaped structures.

[0066] Tests have shown that the tensile strength of the bottle-shaped anchor point is 18-20 MPa.

[0067] Compared with existing technologies, this housing product has the following advantages:

[0068] 1. A specific insert structure formed by additive manufacturing is used to bond the metal and plastic at the interface. The main structure of the insert is larger than the inlet to form a limiting snap-fit. When the composite structure is subjected to tensile or shear forces, the snap-fit ​​structure of the specific insert achieves a tight fit, effectively preventing cracking of the metal and plastic bonding surface, improving waterproof performance, and increasing connection strength.

[0069] 2. Patterns are created on the bonding surfaces of the metal and plastic to form a rough surface, thereby improving the bonding strength between the plastic and the metal after the injection molding process.

[0070] 3. The 3D printed metal substrate and special insert structure are integrated into a single part. On the metal side, except for the mating surface, the appearance of the rest of the parts remains smooth, ensuring that the overall shape of the metal-plastic composite part forms a smooth straight line or curve, enhancing the overall aesthetics.

[0071] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0072] Although this document frequently uses terms such as metal outer frame 1, plastic frame 2, T-shaped protrusion 3, nano protrusion 1 3a, bottle-shaped protrusion 4, and nano protrusion 2 4a, the possibility of using other terms is not excluded. These terms are used merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

[0073] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

Claims

1. A shell product obtained from a method for manufacturing a metal-plastic composite structure, characterized in that, The manufacturing method includes the following steps: S1. A metal outer shell frame is manufactured using 3D printing. An annular groove is formed by recessing the inner periphery of the metal outer shell frame. Several anchor points are recessed at the bottom of the annular groove. Specifically, the anchor points are variable diameter cavities, and the inner diameter of the variable diameter cavity is larger than the diameter of the cavity opening. Several nanopores are opened on the bottom edge of the variable diameter cavity through T processing. S2. Place the metal outer frame into the injection molding equipment and fix it in place, ready for injection molding operation; (1) Dry the injection molding raw materials; (2) Set the barrel temperature; (3) Set the mold temperature; (4) Open multiple valve needles of the injection molding equipment in sequence to inject injection molding material into the metal outer frame in turn; S3. Open the injection molding equipment and take out the finished product. The metal-plastic composite shell is formed. The plastic frame is attached to the inner periphery of the metal shell frame, so that the anchor points are filled with plastic anchor points to form a bonding tensile point. The metal outer frame is made of any one of titanium alloy, aluminum alloy or stainless steel; the plastic frame is made of one or at least two of polyphenylene sulfide, polybutylene terephthalate, high-density polyethylene, polycarbonate, acrylonitrile-butadiene-styrene copolymer. The aforementioned shell product includes a metal outer shell frame, an annular groove is recessed around the inner periphery of the metal outer shell frame, a plurality of anchor points are recessed at the bottom of the annular groove, the anchor points have locking openings, a plastic frame is attached inside the annular groove, and a plurality of anchor point protrusions are integrally fixed to the bottom surface of the plastic frame, which are filled with the plurality of anchor point protrusions, and the anchor point protrusions are locked into the locking openings. The anchor point is T-shaped, with the vertical shaft cavity of the T-shaped cavity forming the locking opening at its end, and the horizontal shaft cavity of the T-shaped cavity forming the inner cavity structure; the anchor point protrusion is T-shaped, with the horizontal shaft of the T-shaped protrusion having a length greater than the width of the end of the vertical shaft, and the right-angle bend between the horizontal shaft and the vertical shaft forming the locking point. or, The anchor point is a bottle-shaped cavity, and the top of the bottle-shaped cavity forms the locking opening. The bottle-shaped cavity gradually expands downward in an arc to form an inner cavity structure. The anchor point protrusion is a bottle-shaped protrusion. The diameter of the lower arc of the bottle-shaped protrusion is larger than the diameter of the upper bottleneck. The arc inflection point between the lower arc and the upper bottle diameter forms the locking point.

2. The casing product as described in claim 1, characterized in that, In step S2, the injection molding equipment is specifically a 250T injection molding machine, and the total injection cycle is 65-70 seconds.

3. The casing product as described in claim 1, characterized in that, In step S2 (1), a desiccant is used to dry the injection molding raw material. The drying temperature is 100-120℃ and the drying time is 3.5-4H.

4. The casing product as described in claim 1, characterized in that, In step S1(2), the temperature of the feed port is 80-90℃, and the temperature of the barrel and the hot runner is 250-270℃; in step S1(3), the temperature of the mold is 145-165℃.

5. The housing product as described in claim 1, characterized in that, In step S2(4), the injection speed is 50–200 mm / s, the injection time is 0.66–0.68 s, and the injection equipment pressure is 2400–2600 kg / cm². 2 ; The holding speed is 45–55 mm / s, and the holding pressure is 2000–2200 kg / cm². 2 The holding time is 15–20 seconds, and the cooling time is 13–20 seconds; the maximum injection pressure does not exceed 2800 kg / cm². 2 .

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