Process for coating hardware glue with silica gel

Abstract

The technology comprises the steps that a hardware glue sealing position is arranged, specifically, a plastic plug is arranged at the top glue sealing position of the hardware, the plastic plug is made of a polyamide composite material containing components in a specific proportion, a nanoscale additive and a shape memory alloy wire are arranged in the plastic plug, and the plastic plug is in prepressing interference fit with the polyamide composite material; and the hardware with the plastic plug is put into a mold containing an upper mold core and a lower mold core to be closed, silica gel injection coating contains specific parameters and a multi-stage pressure control technology, and cooling, mold opening and part taking are carried out. An annular clamping groove is formed in the top of the plastic plug and is clamped and locked with a buckle at the top of the inner cavity of the upper mold core. The plastic plug is cylindrical, the bottom of the plastic plug is planar, and the top of the plastic plug is rounded. Compared with a traditional process, the process has the advantages that the sealing effect can be better controlled through the filling and sealing position of the plastic plug, silica gel is prevented from overflowing, and flash and gel cleaning procedures are reduced; during prepressing interference fit, the plastic plug plays a buffering role, and additives in the plastic plug optimize the performance, so that the hardware can be protected, and the abrasion of the mold core is reduced.

Description

Technical Field

[0001] The present invention relates to the field of hardware part encapsulation with silicone rubber, and in particular to a silicone rubber encapsulation process for hardware parts. Background Art

[0002] In modern manufacturing, silicone rubber encapsulated hardware products are widely used in many fields such as electronics, automotive, and medical devices due to their combination of the excellent properties of silicone rubber, such as softness, insulation, weather resistance, and the hardness, strength, and electrical conductivity of hardware. For example, in electronic devices, silicone rubber encapsulated hardware buttons or connectors can provide good touch feeling and ensure the structural stability; in automotive interiors, such combined products are both beautiful and durable.

[0003] In the common silicone rubber encapsulation process for hardware parts, a steel mold is directly used to press the hardware part to inject and form the silicone rubber part during production. However, this process will result in poor sealing effect, easy overflow of coke and flash, and a large amount of manual labor is required in the subsequent process to clean the glue. The main reason is that the silicone rubber has good fluidity (overflow of glue will occur when the gap at the glue-sealing position exceeds 0.005). If the method of forcibly pre-pressing the hardware part with an insert core is adopted, it is easy to damage the hardware part, and the insert core will also be quickly worn, unable to produce in large quantities, and cannot meet the working requirements of the hardware part encapsulation application. Therefore, a silicone rubber encapsulation process for hardware parts is proposed. Summary of the Invention

[0004] The present invention provides the following technical solutions: A silicone rubber encapsulation process for hardware parts, including the following steps: S1 Setting the glue-sealing position of the hardware part: Set the hardware part, and at least one glue-sealing position is provided at the top of the hardware part; S2 Pre-pressing the hardware part with a plastic plug: Set a plastic plug at the glue-sealing position on the surface of the hardware part set in step S1. The material of the plastic plug is a polyamide composite material, and nano-level additives and shape memory alloy wires are added inside the plastic plug. Then, the plastic plug and the hardware part are pre-pressed with an interference fit; S3 Inserting the hardware part with the plug into the mold: Place the hardware part with the plastic plug set in step S2 into the mold. The mold includes an upper insert core and a lower insert core. The hardware part is inserted into the inside of the lower insert core, and the upper insert core and the lower insert core are closed; S4 Injecting and coating the silicone rubber: First, input the parameters, and then inject the silicone rubber to make the silicone rubber coat the hardware part and the plastic plug, forming a silicone rubber encapsulated hardware part product; S5 Cooling, opening the mold, and taking out the part: After the injection molding is completed and cooled, open the mold to take out the finished product.

[0005] Preferably, annular clamping grooves are formed at the tops of the plastic plugs, and clamping buckles are respectively installed at positions on the top inner cavity of the upper mold core corresponding to the annular clamping grooves, so that mechanical locking is achieved by clamping connection between the clamping buckles and the annular clamping grooves during mold clamping.

[0006] Preferably, the polyamide composite material is composed of a polyamide matrix, a glass fiber reinforcing material, a wear-resistant additive, and an elastomer modifier. The component of the polyamide matrix accounts for 80% - 90% of the entire polyamide composite material, the component of the glass fiber reinforcing material accounts for 5% - 10% of the entire polyamide composite material, the component of the wear-resistant additive accounts for 3% - 5% of the entire polyamide composite material, and the component of the elastomer modifier accounts for 2% - 5% of the entire polyamide composite material.

[0007] Preferably, microscopic diamond-shaped textures are provided at the glue-sealing positions on the tops of the hardware parts. The plastic plugs are all cylindrical in shape, the bottoms of the plastic plugs are flat, the tops of the plastic plugs are rounded, and the height of the plastic plugs is 1 - 3 mm.

[0008] Preferably, the pre-pressing interference amount between the plastic plug and the hardware part is 0.01 - 0.03 mm. The initial size of the plastic plug is larger than the gap of the glue-sealing position, and a pressure of 5 - 10 MPa is applied to the upper mold core during pre-pressing mold clamping, so that the plastic plug elastically deforms and closely fits with the hardware part.

[0009] Preferably, the process parameters included in the silicone injection in step S4 are injection temperature, injection pressure, holding pressure time, and cooling time. The injection temperature is 150 - 180 °C, the injection pressure is 80 - 120 MPa, the holding pressure time is 10 - 20 seconds, and the cooling time is 15 - 30 seconds.

[0010] Preferably, the shape memory alloy wire is composed of a nickel-titanium-copper alloy. The diameter of the shape memory alloy wire is 0.05 - 0.15 mm, and the shape memory alloy wire is arranged in a three-dimensional spiral structure inside the plastic plug.

[0011] Preferably, diamond-like carbon wear-resistant coatings are coated on the working surfaces of the upper mold core and the lower mold core, and the thickness of the diamond-like carbon wear-resistant coating is 2 - 5 μm.

[0012] Preferably, during the injection in step S4, the silicone injection system adopts an injection process with multi-stage pressure control. The injection process with multi-stage pressure control includes an initial low-pressure filling stage, a medium-speed pressure boosting stage, and a high-pressure holding stage. The pressure in the initial low-pressure filling stage is 30 - 50 MPa, the pressure in the medium-speed pressure boosting stage is 60 - 90 MPa, and the high-pressure holding stage is 100 - 120 MPa.

[0013] Preferably, the nano-additive includes a plasma surface-treated carbon nanotube and nano-silica composite, the mass fraction of the carbon nanotube is 1.2% - 2.8%, and the mass fraction of the nano-silica is 0.8% - 1.5%.

[0014] In summary, compared with the prior art, the present invention provides a silicone-coated hardware glue process, which has the following beneficial effects: 1. By setting a plastic plug at the glue-sealing position of the hardware, the present invention uses the plastic plug to fill the glue-sealing position of the hardware. Compared with the traditional process of directly pressing the hardware by a steel mold for silicone injection molding, this process can better control the sealing effect of the glue-sealing position. The plastic plug and the hardware are pre-pressed with an interference fit, which can effectively prevent the overflow of silicone during the injection process. Even if the gap at the glue-sealing position is slightly larger, the possibility of glue overflow can be greatly reduced, thereby reducing the generation of flash and avoiding the problem of consuming a large amount of labor in the subsequent process to clean the glue. 2. By the way of pre-pressing the plastic plug and the hardware with an interference fit, compared with the traditional way of forcibly pre-pressing the hardware by a mold core with an interference fit, the plastic plug plays a buffering role, so that during the pre-pressing process, the plastic plug can evenly transfer the pressure to the hardware, avoiding the situation that the hardware is damaged by local excessive pressure. At the same time, the performance of the plastic plug is further optimized by adding nano-additives and shape memory alloy wires inside the plastic plug. The nano-additives can enhance the wear resistance, hardness and other properties of the plastic plug, while the shape memory alloy wire can enable the plastic plug to better recover its shape after being deformed under a certain pressure, further ensuring the stability and reliability of the plastic plug during the pre-pressing interference fit process, and thus better realizing the problems of protecting the hardware and reducing the wear of the mold core. Description of the Drawings

[0015] Figure 1 is the process flow chart of the present invention.

[0016] Figure 2 is the schematic diagram of the implementation state of the process structure of the present invention.

[0017] Description of the Reference Numerals: 1. Hardware; 2. Plastic plug; 3. Lower mold core; 4. Upper mold core; 5. Silicone. Detailed Embodiments

[0018] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0019] The present invention provides a technical solution, a silicone rubber coating on metal bonding process, including a metal part 1, a plastic plug 2, a lower die core 3, an upper die core 4 and silicone rubber 5: Please refer to Figure 1 , the silicone rubber coating on metal bonding process of the present invention includes the following steps; S1 Metal part sealant position setting: Set the metal part 1, and at least one sealant position is provided at the top of the metal part 1; Please refer to Figure 2 , S2 Plastic plug pre-pressing on the metal: Set the plastic plug 2 at the sealant position on the surface of the metal part 1 set in step S1. The material of the plastic plug 2 is a polyamide composite material, and a nano-level additive and a shape memory alloy wire are added inside the plastic plug 2. Then, the plastic plug 2 and the metal part 1 are pre-pressed with interference fit. The specific implementation method of the above process is; First, prepare the plastic plug 2: Prepare the raw materials according to the composition ratio of the polyamide composite material. Mix 80% - 90% of the polyamide matrix, 5% - 10% of the glass fiber reinforcing material, 3% - 5% of the wear-resistant additive and 2% - 5% of the elastomer modifier as the base material of the plastic plug 2. Prepare the nano-level additive, which is a composite of carbon nanotubes and nano-silica treated by plasma surface treatment, and mix it according to the mass fraction of carbon nanotubes of 1.2 - 2.8% and the mass fraction of nano-silica of 0.8 - 1.5%. Prepare the shape memory alloy wire, select a nickel-titanium-copper alloy to make a shape memory alloy wire with a diameter of 0.05 - 0.15 mm, and fully mix the prepared nano-level additive, shape memory alloy wire and the base raw material of the polyamide composite material. Among them, during the mixing process of the shape memory alloy wire, it is necessary to ensure that it is arranged in a three-dimensional spiral structure inside the plastic plug 2. Use a molding device to make the mixed material into a cylindrical plastic plug 2, with the bottom of the plastic plug 2 set as a plane and the top as a rounded corner, and the height is 1 - 3 mm; Preparation of the sealant position of the metal part 1: Determine at least one sealant position at the top of the metal part 1, and set microscopic diamond-shaped textures at the sealant position to prepare for the subsequent setting of the plastic plug 2; Pre - press interference fit between the plastic plug 2 and the hardware part 1: Place the prepared plastic plug 2 at the sealant position on the surface of the hardware part 1. Since the initial size of the plastic plug 2 is larger than the gap of the sealant position, the plastic plug 2 is in a relatively loose placement state at this time. Use a pressure device to apply a pressure of 5 - 10 MPa to the upper die insert during pre - press molding. Under the action of the pressure, the plastic plug 2 begins to elastically deform. When the shape - memory alloy wire inside the plastic plug 2 is deformed under pressure, its shape - memory property will cause it to have a tendency to resist deformation. At the same time, the polyamide composite base structure of the plastic plug 2 also undergoes elastic deformation under pressure. During this process, the nano - scale additives inside the plastic plug 2 will enhance the wear resistance and hardness of the plastic plug 2 and other properties, enabling it to better withstand the pressure and also reducing the wear of the plastic plug 2 during the deformation process. As the pressure is continuously applied, the plastic plug 2 gradually undergoes elastic deformation until a pre - press interference fit state is reached between the plastic plug 2 and the hardware part 1, with an interference amount of 0.01 - 0.03 mm. At this time, the plastic plug 2 is tightly fitted on the sealant position of the hardware part 1, completing the pre - press interference fit operation. During this process, the plastic plug 2 plays a buffering role, evenly transmitting the pressure to the hardware part 1 and preventing the hardware part 1 from being damaged by excessive local pressure; S3 Insert the hardware part with a plug into the mold: Place the hardware part 1 with the plastic plug 2 set in step S2 into the mold. The mold includes an upper die insert 4 and a lower die insert 3. The hardware part 1 is inserted inside the lower die insert 3, and the upper die insert 4 and the lower die insert 3 are closed. The specific implementation method of the above process is as follows; Preparation before insertion into the mold: Check whether the working surfaces of the upper die insert 4 and the lower die insert 3 of the mold are coated with a diamond - like carbon wear - resistant coating, and ensure that the coating thickness is between 2 - 5 μm. If the coating is damaged or the thickness does not meet the requirements, repair or re - coat it. Check whether the buckle at the top of the inner cavity of the upper die insert 4 is installed correctly and can work normally. The buckle should correspond to the annular slot at the top of the plastic plug 2 to ensure mechanical locking during mold closing. Clean the inside of the lower die insert 3 to ensure there are no sundries, oil stains, etc., to ensure that the hardware part 1 can be inserted smoothly. Check the hardware part 1 with the plastic plug 2 to ensure that the pre - press interference fit between the plastic plug 2 and the hardware part 1 meets the requirements, that is, the pre - press interference amount is within the range of 0.01 - 0.03 mm, the plastic plug 2 is tightly fitted on the sealant position of the hardware part 1, and confirm that the state of the plastic plug 2 is normal, and the annular slot at its top is complete and in the correct position for cooperation with the buckle of the upper die insert 4; Inserting the hardware part 1 into the mold: Insert the hardware part 1 with the plastic plug 2 into the interior of the lower mold core 3. During the insertion process, use the microscopic diamond texture at the sealant position on the top of the hardware part 1 and the shape structure (such as positioning structures if necessary) inside the lower mold core 3 for preliminary positioning to ensure that the hardware part 1 is accurately placed at the predetermined position inside the lower mold core 3. Operate the mold closing equipment to slowly move the upper mold core 4 downward towards the lower mold core 3. During this process, use the guiding structure of the mold itself (such as guide pillars, etc.) to ensure the preliminary alignment of the upper mold core 4 and the lower mold core 3, preparing for subsequent accurate mold closing. As the upper mold core 4 continues to move downward, when approaching the mold closing position, the buckle at the top of the inner cavity of the upper mold core 4 starts to contact and gradually engage with the annular slot at the top of the plastic plug 2. During the engagement process of the buckle and the annular slot, the upper mold core 4 and the lower mold core 3 are further accurately aligned, and finally complete mold closing. At this time, the mechanical locking of the buckle and the annular slot ensures the accuracy and stability of mold closing, and at the same time accurately fixes the positions of the hardware part 1 and the plastic plug 2 in the mold, preparing for the subsequent silicone injection coating process; S4 Silicone injection coating: First, input the parameters, and then inject silicone 5 so that the silicone 5 coats the hardware part 1 and the plastic plug 2 to form a silicone-coated hardware part 1 product; S5 Cooling, mold opening, and part removal: After the injection molding is completed and cooled, open the mold to remove the finished product.

[0020] In the above steps, annular grooves are provided at the tops of the plastic plugs 2, and buckles are installed at the positions corresponding to the annular grooves at the tops of the inner cavities of the upper mold cores 4, so that mechanical locking is achieved by the buckles engaging with the annular grooves during mold clamping. By adding the annular grooves and buckles, the positions of the plastic plugs 2 and the metal parts 1 relative to the upper mold cores 4 can be accurately positioned during mold clamping, avoiding the possible offset phenomenon during mold clamping, which is crucial for the subsequent silicone injection coating process. Because the accurate positional relationship can ensure that the silicone is evenly coated around the metal parts 1 and the plastic plugs 2, improving the quality and appearance consistency of the product. Secondly, the mechanical locking provides a stable mold clamping structure. During the silicone injection process, when the silicone is under injection pressure, this locking structure can prevent the plastic plugs 2 and the metal parts 1 from shifting in the mold, ensuring the stability of the entire structure. And this locking method, compared with other complex locking mechanisms, has a simple structure, high reliability, is not prone to failures, reduces the cost and time of equipment maintenance. At the same time, since the engagement between the buckles and the annular grooves is a mechanical structure fit, no additional power source or complex control system is required, making the entire mold clamping process more efficient and convenient, improving the production efficiency. The polyamide composite material is composed of a polyamide matrix, a glass fiber reinforcing material, a wear-resistant additive, and an elastomer modifier. The component of the polyamide matrix accounts for 80% - 90% of the entire polyamide composite material, the component of the glass fiber reinforcing material accounts for 5% - 10% of the entire polyamide composite material, the component of the wear-resistant additive accounts for 3% - 5% of the entire polyamide composite material, and the component of the elastomer modifier accounts for 2% - 5% of the entire polyamide composite material. Microscopic diamond-shaped textures are provided at the glue-sealing positions at the tops of the metal parts 1, and the added diamond-shaped textures increase the surface roughness of the glue-sealing positions of the metal parts 1. This increase in roughness can effectively enhance the friction force between the metal parts 1 and the plastic plugs 2. When the plastic plugs 2 and the metal parts 1 are in a pre-pressed interference fit, the larger friction force helps prevent the plastic plugs 2 from sliding or shifting when subjected to external forces (such as the pressure during silicone injection, etc.). Moreover, the shape design of the diamond-shaped textures forms a structure similar to mechanical interlocking on the contact surface. When the plastic plugs 2 are pressed into the glue-sealing positions, the corners of the diamond-shaped textures can partially embed into the surfaces of the plastic plugs 2, further enhancing the bonding force between the two. From the perspective of manufacturing process, this microscopic diamond-shaped texture can be manufactured by precision etching or mold forming processes to ensure the dimensional accuracy and uniformity of the texture. This not only helps improve the consistency of the product, but also ensures that the glue-sealing positions of each metal part 1 and the plastic plugs 2 can achieve the best matching effect. The shapes of the plastic plugs 2 are all cylindrical, and the cylindrical plastic plugs 2 are a well-considered design choice. The cylindrical shape has good symmetry. When mating with the glue-sealing positions of the metal parts 1, no matter from which direction, its contact state with the glue-sealing position is similar, which helps evenly withstand the pressure from all directions during pre-pressing and silicone injection processes.Moreover, the positioning of the cylindrical outer surface in the mold is more convenient. When inserting the hardware part 1 with the plastic plug 2 into the lower mold core 3, the cylindrical shape can better adapt to the internal structure of the mold, reduce the resistance during the insertion process, and improve production efficiency. In addition, the cylindrical plastic plug 2 is easier to mold during the manufacturing process. Compared with other complex shapes, the cylindrical mold is simple to manufacture, which can reduce production costs, and can ensure the dimensional accuracy and consistency of products during mass production. The bottom of the plastic plug 2 is set as a flat surface. The added flat bottom can provide a stable support surface. When contacting the sealing position of the hardware part 1, it can evenly disperse the pressure. When applying a pre-pressing interference pressure to the plastic plug 2, the flat bottom can ensure that the pressure is vertically transmitted to the sealing position of the hardware part 1, avoiding damage to the hardware part 1 due to excessive local pressure. During the mold closing process, the flat bottom also helps to keep close contact with the hardware part 1 and prevent the silicone from leaking out from the bottom. From the perspective of manufacturing and assembly, the design of the flat bottom makes it easier to control the dimensional accuracy of the plastic plug 2 during the manufacturing process and easier to position and install with the hardware part 1 during assembly. The top of the plastic plug 2 is set as a rounded corner. The rounded corner setting at the top of the plastic plug 2 is an optimized design detail. The existence of the rounded corner avoids the sharp corners at the top. During the mold closing process, when contacting the buckle and other structures at the top of the inner cavity of the upper mold core 4, the rounded corner can reduce the stress concentration phenomenon. Stress concentration may cause damage or deformation of the plastic plug 2 at these positions, while the rounded corner setting effectively disperses the stress during contact and improves the service life of the plastic plug 2. In addition, the rounded corner setting is also beneficial to the flow of silicone during the silicone injection process. When the silicone flows to the top of the plastic plug 2, the shape of the rounded corner can guide the silicone to flow more smoothly, avoiding the formation of dead corners or vortices at the top, thereby ensuring the uniformity of silicone coating and improving the quality of the product. The height of the plastic plug 2 is 1 - 3 mm, the pre-pressing interference amount between the plastic plug 2 and the hardware part 1 is 0.01 - 0.03 mm, the initial size of the plastic plug 2 is larger than the gap of the sealing position, and a pressure of 5 - 10 MPa is applied to the upper mold core during pre-pressing and mold closing, causing the plastic plug to elastically deform and closely fit with the hardware part. The process parameters included in the silicone injection in step S4 are injection temperature, injection pressure, holding time, and cooling time. The injection temperature is 150 - 180 °C, the injection pressure is 80 - 120 MPa, the holding time is 10 - 20 seconds, and the cooling time is 15 - 30 seconds. The shape memory alloy wire is composed of nickel-titanium-copper alloy. The diameter of the shape memory alloy wire is 0.05 - 0.15 mm. The shape memory alloy wire is arranged in a three-dimensional spiral structure inside the plastic plug 2. The working surfaces of the upper mold core 4 and the lower mold core 3 are both coated with a diamond-like carbon wear-resistant coating. With the added diamond-like carbon wear-resistant coating, during the frequent opening and closing of the mold, the working surfaces of the upper mold core 4 and the lower mold core 3 will continuously frictionally contact with other components.The diamond-like carbon wear-resistant coating has extremely high hardness and can effectively resist this friction, greatly reducing the wear on the surface of the mold core. This means that the service life of the mold is significantly extended. Compared with the mold without this coating, after long-term use, the mold core coated with the diamond-like carbon wear-resistant coating can still maintain good surface flatness and dimensional accuracy. This is crucial for ensuring the stability of product quality because even minor wear on the mold surface can lead to product dimensional deviation or surface quality degradation. Moreover, the diamond-like carbon wear-resistant coating has a low surface energy, making it easier for the silicone product to detach from the mold surface after molding. This characteristic can effectively reduce the demolding time during the production process and improve production efficiency. At the same time, since the demolding process is smoother, it also reduces the possibility of damaging the product during demolding, increasing the yield rate of the product. Meanwhile, during the silicone injection and coating process, some chemical substances will react with the surface of the mold core. The diamond-like carbon wear-resistant coating has good chemical stability and can resist the erosion of chemical substances such as silicone raw materials and possible impurities. This ensures that the mold can still work properly in a complex chemical environment and will not affect the performance of the mold and the quality of the product due to chemical corrosion. The thickness of the diamond-like carbon wear-resistant coating is 2 - 5μm. During the injection in step S4, the silicone injection system adopts an injection process with multi-stage pressure control. The injection process with multi-stage pressure control includes an initial low-pressure filling stage, a medium-speed pressure-boosting stage, and a high-pressure holding stage. The pressure in the initial low-pressure filling stage is 30 - 50MPa, the pressure in the medium-speed pressure-boosting stage is 60 - 90MPa, and the high-pressure holding stage is 100 - 120MPa. The nano-additives include plasma surface-treated carbon nanotubes and nano-silica composites. The mass fraction of carbon nanotubes is 1.2% - 2.8%, and the mass fraction of nano-silica is 0.8% - 1.5%.

[0021] In this solution, a plastic plug 2 is set at the sealant position of the hardware part 1, and the plastic plug 2 is used to fill the sealant position of the hardware part 1. Compared with the traditional process of directly pressing the hardware part by the steel mold for silicone injection molding, this process can better control the sealing effect of the sealant position. The plastic plug 2 is in a pre-pressed interference fit with the hardware part 1, which can effectively prevent the overflow of silicone 5 during the injection process. Even if the gap at the sealant position is slightly larger, it can greatly reduce the possibility of glue overflow, thereby reducing the generation of flash and avoiding the problem of consuming a large amount of labor in the subsequent process to clean the glue.

[0022] In this solution, the plastic plug 2 and the hardware part 1 are pre-pressed with interference fit. Compared with the traditional method of forcibly pre-pressing the hardware part by the mold core, the plastic plug 2 plays a buffering role, enabling the plastic plug 2 to evenly transfer the pressure to the hardware part 1 during the pre-pressing process, avoiding the situation that the hardware part 1 is damaged by excessive local pressure. At the same time, the performance of the plastic plug 2 is further optimized by adding nano-level additives and shape memory alloy wires inside the plastic plug 2, enabling the wear resistance, hardness and other properties of the plastic plug 2 to be enhanced by the nano-level additives, while the shape memory alloy wire enables the plastic plug 2 to better recover its shape after being deformed under a certain pressure, further ensuring the stability and reliability of the plastic plug 2 during the pre-pressing interference fit process, so as to better achieve the problems of protecting the hardware part and reducing the wear of the mold core.

[0023] It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or also includes elements inherent to such process, method, article or device.

[0024] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for bonding hardware with silicone rubber, characterized in that, It includes the following steps: S1 Setting the sealant position of the hardware: The top of the hardware (1) has at least one sealant position; S2 Pre-pressing the plastic plug onto the hardware: A plastic plug (2) is set at the sealant position on the surface of the hardware (1) in step S1. The material of the plastic plug (2) is a polyamide composite material. At the same time, nano-scale additives and shape memory alloy wires are added inside the plastic plug (2). Subsequently, the plastic plug (2) is pre-pressed with an interference fit with the hardware (1); S3 Inserting the hardware with the plug into the mold: The hardware (1) with the plastic plug (2) set in step S2 is placed in the mold. The mold includes an upper mold core (4) and a lower mold core (3). The hardware (1) is inserted into the inside of the lower mold core (3), and the upper mold core (4) and the lower mold core (3) are closed; S4 Injecting and coating with silicone: First, parameters are input. Secondly, silicone (5) is injected to coat the hardware (1) and the plastic plug (2) to form a silicone-coated hardware (1) product; S5 Cooling, opening the mold, and taking out the part: After injection molding and cooling, the mold is opened to take out the finished product.

2. The silicone rubber-coated hardware glue process according to claim 1, wherein: An annular groove is provided at the top of each of the plastic plugs (2). At the position corresponding to the annular groove at the top of the inner cavity of the upper mold core (4), a buckle is installed, so that the buckle is mechanically locked with the annular groove during mold closing.

3. A silicone-coated hardware glue process according to claim 1, characterized in that: The polyamide composite material is composed of a polyamide matrix, a glass fiber reinforcing material, a wear-resistant additive, and an elastomer modifier. The component of the polyamide matrix accounts for 80% - 90% of the entire polyamide composite material. The component of the glass fiber reinforcing material accounts for 5% - 10% of the entire polyamide composite material. The component of the wear-resistant additive accounts for 3% - 5% of the entire polyamide composite material. The component of the elastomer modifier accounts for 2% - 5% of the entire polyamide composite material.

4. A silicone - coated hardware glue process according to claim 1, characterized in that: Microscopic diamond-shaped textures are provided at the sealant positions at the top of the hardware (1). The shapes of the plastic plugs (2) are all cylindrical. The bottom of the plastic plug (2) is flat. The top of the plastic plug (2) is rounded. The height of the plastic plug (2) is 1 - 3 mm.

5. A silicone-coated hardware glue process according to claim 1, characterized in that: The pre-pressing interference amount between the plastic plug (2) and the hardware (1) is 0.01 - 0.03 mm. The initial size of the plastic plug (2) is larger than the gap of the sealant position. When pre-pressing and closing the mold, a pressure of 5 - 10 MPa is applied to the upper mold core, so that the plastic plug elastically deforms and closely fits with the hardware.

6. The silicone rubber coated hardware glue process according to claim 1, wherein: The process parameters included in the silicone injection in step S4 are injection temperature, injection pressure, holding time, and cooling time. The injection temperature is 150 - 180 °C. The injection pressure is 80 - 120 MPa. The holding time is 10 - 20 seconds. The cooling time is 15 - 30 seconds.

7. A silicone-coated hardware glue process according to claim 1, characterized in that: The shape memory alloy wire is composed of a nickel-titanium-copper alloy. The diameter of the shape memory alloy wire is 0.05 - 0.15 mm. The shape memory alloy wire is arranged in a three-dimensional spiral structure inside the plastic plug (2).

8. A silicone-coated hardware glue process according to claim 1, characterized in that: The working surfaces of the upper mold core (4) and the lower mold core (3) are both coated with a diamond-like carbon wear-resistant coating, and the thickness of the diamond-like carbon wear-resistant coating is 2-5 μm.

9. A silicone-coated hardware glue process according to claim 1, characterized in that: During the injection in step S4, the silicone injection system adopts an injection process with multi-stage pressure control. The injection process with multi-stage pressure control includes an initial low-pressure filling stage, a medium-speed pressure boosting stage, and a high-pressure pressure holding stage. The pressure in the initial low-pressure filling stage is 30-50 MPa, the pressure in the medium-speed pressure boosting stage is 60-90 MPa, and the high-pressure pressure holding stage is 100-120 MPa.

10. A silicone-coated hardware glue process according to claim 1, characterized in that: The nano-additive includes a carbon nanotube and nano-silica composite treated by plasma surface treatment. The mass fraction of the carbon nanotube is 1.2% - 2.8%, and the mass fraction of the nano-silica is 0.8% - 1.5%.

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