Forming method of electronic watchband with buckle structure
By using two TPU injection methods during the forming process of the electronic watch strap, the scratching and damage of the watch body when the slider is removed is solved, and the production efficiency and product aesthetics are improved.
Patent Information
- Application Number
- CN202411741215.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-29
- Publication Date
- 2025-03-04
AI Technical Summary
The existing electronic watch strap molding method with a buckle structure can easily cause scratching or damage to the surface body when removing the slider, affecting production efficiency and product aesthetics.
Using the method of two TPU injections, first inject the TPU into the fixture to form the surface body, and form a ring buckle structure above the surface body, and then remove the slider to prevent the slider from clamping between the ring buckle and the surface body when heat-setting.
Through this method, scratching and breaking of the surface body when the slider is removed is avoided, and production efficiency and product aesthetics and quality are improved.
Smart Images
Figure CN119550550A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of watch straps, and more specifically, to a method for forming an electronic watch strap with a buckle structure. Background Art
[0002] As a common wearable device accessory, the design and manufacturing technology of electronic watch straps has been widely used and developed. As consumers' requirements for the appearance and functions of electronic watch straps continue to increase, manufacturers continue to explore new materials and technologies to improve the aesthetics and durability of products. Existing electronic watch straps are usually made of resin materials, which have good elasticity and wear resistance and can meet most usage requirements. However, as the market's requirements for product details become increasingly stringent, the existing molding methods have exposed some shortcomings in practical applications.
[0003] In the existing molding process of electronic watch bands with loop structures, an integrated molding method is usually adopted. Specifically, the nail buckle, head grain and slider are first buried in the fixture, and then the molten resin material is injected to solidify it to form a watch body. At the same time, the position of the watch body corresponding to the slider forms a loop structure, and then the slider is taken out to obtain the watch band. Since the slider is easily clamped in the loop structure and the watch body during thermal curing, when the slider is taken out, the loop structure and the watch body need to be spread apart during the removal process, which is easy to cause scratches or damage to the watch body, thereby reducing production efficiency and product aesthetics. And due to the weight of the slider, during the molding process of the watch body, it is easy to cause indentations in the area of the watch band corresponding to the loop structure, which seriously affects the overall aesthetics of the electronic watch band. Secondly, during the removal process of the sliding block, the surface of the watch body may be scratched due to friction, further reducing the appearance quality of the product. Further research is needed for this purpose. Summary of the invention
[0004] The present application improves production efficiency and product quality, and provides a method for forming an electronic watchband with a buckle structure. The method for forming an electronic watchband with a buckle structure comprises the following steps: 1) placing the material in a jig, injecting molten TPU, and solidifying the TPU to obtain a TPU body, on which the embedded material is fixed, and two symmetrically arranged ring-buckle connecting parts are formed on the side of one side of the TPU body; 2) Place a sliding block between the two buckle connecting parts, inject TPU again, solidify it, form a buckle on the TPU body, and connect the two ends of the buckle to the two buckle connecting parts respectively, then take out the sliding block to obtain an electronic watch strap with a buckle structure.
[0005] By adopting the above technical solution, the material is placed in the fixture, and after TPU is injected, the connection between TPU and TPU body is stably made, and the buckle connection part is formed to play a precise positioning role, which is convenient for the subsequent formation of the buckle. After the TPU body is formed, the slider is placed in it to avoid indentation on the surface of the TPU body, thereby improving its aesthetics and quality. At the same time, secondary TPU molding is adopted to connect the stable buckle structure, reduce the possibility of damage and falling off, and improve its aesthetics and practicality.
[0006] Compared with one-time molding, this application has the following advantages: The sliding block will not sink into the TPU surface body. Therefore, after molding, the sliding block will not be stuck between the buckle structure and the TPU surface body, so it is easy to remove and will not cause scratches on the TPU surface body during the removal process. In addition, during the processing, the sliding block is placed on the already solidified TPU surface body, and will not be affected by the weight and produce indentations, which improves the aesthetics of the product.
[0007] At the same time, the TPU used in this application has better flexibility and elasticity, making the slider easy to remove and not easy to affect the surface.
[0008] The materials of the present application are nail buttons and head grains.
[0009] Preferably, the step 2) further includes removing burrs; the specific process is as follows: Place a sliding block between the two buckle connecting parts, inject TPU again, solidify it, form a buckle on the top of the TPU body, and connect the two ends of the buckle to the two buckle connecting parts respectively. Then take out the sliding block to obtain an electronic watch strap with a buckle structure.
[0010] By adopting the above technical solution, it is ensured that during the two TPU injection processes, the placement and removal of the sliding block will not cause indentations on the TPU surface, thereby improving the overall aesthetics of the electronic watch strap. At the same time, the operation of removing the burrs makes the final electronic watch strap with a buckle structure smoother, thus improving the appearance quality of the product.
[0011] Preferably, the TPU is a modified TPU, and the modified TPU is composed of the following raw materials in weight percentage: TPU 78-95% Contains 0.1-1% hydroxy toughening agent N,N'-(4-methyl-1,3-phenylene)bismaleimide 0.5-1.5% Polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer 1-3% Polysiloxane derivatives 1-3% Filler 3-10% Catalyst 0.01-0.05% The balance is compatibilizer.
[0012] In order to further improve the connection stability between the buckle connecting part and the buckle, the present application adopts a hydroxyl-containing toughening agent, N,N'-(4-methyl-1,3-phenylene) bismaleimide, polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, and a polysiloxane derivative for compounding, and with the assistance of a compatibilizer, the TPU is modified, while the catalyst plays a promoting role and the filler plays a filling and reinforcing role, so that the obtained modified TPU has better bonding performance, thermal stability and physical properties. Therefore, when used in the process of the present application, it has better physical properties, and further improves the connection stability between the buckle connecting part and the buckle, thereby improving the quality of the product.
[0013] Specifically: The addition of hydroxyl-containing toughening agents enhances the toughness of TPU, thereby improving the impact resistance and durability of the strap. The addition of N,N'-(4-methyl-1,3-phenylene) bismaleimide further strengthens the mechanical properties of TPU, improves its bonding strength and heat resistance, and ensures that the strap can still maintain good physical properties under high temperature conditions. The introduction of polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymers not only improves the toughness, wear resistance and chemical corrosion resistance of TPU, but also promotes the dispersion and compatibility between the components, making the material more uniform. The use of polysiloxane derivatives improves the surface properties of TPU, increases flexibility and elasticity, while enhancing lubricity and wear resistance, reducing the adhesion and adhesion of substances on the surface of TPU, making it easier to clean and maintain. The selection of fillers greatly improves the mechanical properties of TPU, such as tensile strength and tear strength, making it tougher and more durable. The appropriate addition of catalyst and compatibilizer optimizes the modification process, improves the compatibility and processing performance of the raw material system, and ensures the stable quality of the final product.
[0014] In summary, the hydroxyl-containing toughening agent, N,N'-(4-methyl-1,3-phenylene) bismaleimide, polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, and polysiloxane derivatives play a synergistic role, so that the comprehensive performance of the modified TPU is better. The use of the modified TPU effectively improves the comprehensive performance of the electronic watch strap with a buckle structure, making it outstanding in durability, aesthetics and functionality.
[0015] Preferably, the hydroxyl-containing toughening agent is a branched hydroxyl polyester and / or silane-PEG-hydroxyl.
[0016] By adopting the above technical solution, the introduction of branched hydroxy polyester and silane-PEG-hydroxy can significantly improve the mechanical properties, heat resistance, surface properties and weather resistance of TPU. When these two toughening agents are used at the same time, a synergistic effect will be produced, further improving the overall performance of TPU.
[0017] Preferably, the hydroxyl-containing toughening agent is composed of branched hydroxyl polyester and silane-PEG-hydroxyl in a weight ratio of 1:(0.1-0.5).
[0018] By adopting the above technical scheme, the hydroxyl-containing toughening agent is composed of branched hydroxyl polyester and silane-PEG-hydroxyl in a weight ratio of 1: (0.1-0.5), which can produce a synergistic effect and jointly improve the mechanical properties, heat resistance, surface properties and weather resistance of TPU.
[0019] Preferably, the polysiloxane derivative is methacrylate mono-terminated dimethyl polysiloxane and / or aminopropyl di-terminated polydimethyl polysiloxane.
[0020] By adopting the above technical solutions, methacrylate mono-terminated dimethyl polysiloxane can improve the surface properties of TPU, increase its flexibility and elasticity, and adjust its hardness; aminopropyl di-terminated polydimethyl siloxane can enhance the lubricity and wear resistance of TPU, reduce the adhesion and adhesion of substances on the surface of TPU, make it easier to clean and maintain, and improve its heat resistance and weather resistance. These improvements make the electronic watch strap with a buckle structure more durable, not easy to damage during use, and have a high surface finish, which improves the overall quality of the product.
[0021] Preferably, the polysiloxane derivative is composed of methacrylate mono-terminated dimethyl polysiloxane and aminopropyl di-terminated polydimethyl polysiloxane in a weight ratio of 1:(1-3).
[0022] By adopting the above technical solution, the polysiloxane derivative is composed of methacrylate mono-terminated dimethyl polysiloxane and aminopropyl di-terminated polydimethyl siloxane in a weight ratio of 1: (1-3), which produces a synergistic effect and jointly improves the dispersibility, compatibility, lubricity, weather resistance and interface interaction of the filler. This helps to improve the overall performance of TPU, enhance its mechanical strength, wear resistance and surface smoothness, while reducing the adhesion and attachment of substances on the surface of TPU, making it easier to clean and maintain, and improving heat resistance and weather resistance.
[0023] Preferably, the filler is porous silica aerogel.
[0024] By adopting the above technical solution, the porous silica aerogel is selected as the filler, which can significantly enhance the mechanical properties of TPU, especially the tensile strength and tear strength, making it tougher and more durable. The introduction of porous silica aerogel not only improves the mechanical properties of TPU, but also enhances its wear resistance and surface lubricity, effectively avoiding scratches and damage to the TPU surface when removing the slider.
[0025] Preferably, the compatibilizer is one or more of maleic anhydride grafted EVA, maleic anhydride grafted HMA, and maleic anhydride grafted EMA (to improve the compatibility of the raw material system).
[0026] By adopting the above technical solution, the compatibility of the raw material system is improved, and each component is distributed more evenly in the TPU matrix, thereby improving the overall performance of the modified TPU, including mechanical properties, heat resistance, weather resistance and surface properties. In addition, by using maleic anhydride grafted EVA, maleic anhydride grafted HMA or maleic anhydride grafted EMA as a compatibilizer, it is possible to effectively avoid scratching the TPU surface when removing the slider, ensuring the smoothness and aesthetics of the strap surface.
[0027] Preferably, the modified TPU is prepared by the following method: According to weight percentage, hydroxyl-containing toughening agent 0, N,N'-(4-methyl-1,3-phenylene) bismaleimide, polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, polysiloxane derivative, filler, catalyst and compatibilizer are weighed and mixed evenly, heated to melt, and then TPU is added, fused and mixed evenly to obtain modified TPU.
[0028] In summary, the preparation method of the modified TPU can make the various materials fully and evenly mixed, thereby not only improving the basic performance of TPU, but also further optimizing the comprehensive performance of TPU through the synergistic effect of various additives, making it more suitable for the molding of electronic watch straps with a buckle structure, making the buckle structure connection stable, and improving the aesthetics, practicality, processing efficiency and quality of the product.
[0029] In summary, the present application includes at least one of the following beneficial technical effects: 1. The nail buckle and the head are buried in the fixture, and the TPU surface formed by the injection and curing of TPU ensures the stable connection between the nail buckle and the head, and improves the stability and reliability of the overall structure; 2. After the buckle connection is formed, a sliding block is placed on the TPU body and secondary injection molding is performed to avoid indentations on the surface of the TPU body and improve the overall aesthetics of the electronic watch strap; 3. The hydroxy-containing toughening agent, N,N'-(4-methyl-1,3-phenylene) bismaleimide, polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, and polysiloxane derivatives play a synergistic role, making the overall performance of the modified TPU better. The use of the modified TPU effectively improves the overall performance of the electronic watch strap with a buckle structure, making it outstanding in durability, aesthetics and functionality. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1It is a schematic diagram of the structure of an electronic watch band with a buckle structure of the present application.
[0031] Explanation of the reference numerals: 1. material; 11. nail button; 12. head particle; 2. TPU surface body; 21. buckle connecting part; 3. buckle; 4. buckle structure. DETAILED DESCRIPTION
[0032] The following is combined with Figure 1 The present application is further described in detail with reference to the accompanying drawings and embodiments.
[0033] Some raw material sources: TPU is Lubrizol Isoplast 2560ETPU; The specific surface area of porous silica aerogel is about 600-800㎡ / g, and the pore size is 10-50nm; Polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, molecular formula: [C 2 H 4 O]n[C 3 H 6 O]m[C 2 H 4 O]n, wherein n is 10-12 and m is 10-15; The catalyst is an organic bismuth catalyst, model BCAT-E16, from Guangzhou Yourun Synthetic Materials Co., Ltd.; Branched hydroxy polyester Covestro 670; Silane-PEG-hydroxy is triethoxysilane polyethylene glycol hydroxy with a molecular weight of 1000-2000; Methacrylate mono-terminated dimethyl polysiloxane has a molecular weight of 1000-2000; Aminopropyl dicapped polydimethylsiloxane 1000-2000; Maleic anhydride grafted EVA American DuPont 21E830.
[0034] Preparation example of modified TPU Preparation Example 1 A modified TPU is prepared by the following method: According to the weight percentage, 0.1% hydroxyl-containing toughener, 1.5% N,N'-(4-methyl-1,3-phenylene) bismaleimide, 1% polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, 3% polysiloxane derivatives, 3% fillers, 0.01% catalyst and compatibilizer are weighed and mixed evenly, heated to 170°C to completely melt, and then 90% TPU is added to fully blend and the materials are fully mixed to obtain modified TPU.
[0035] The hydroxy toughening agent is a branched hydroxy polyester; the polysiloxane derivative is an aminopropyl double-terminated polydimethylsiloxane; the filler is a porous silica aerogel; and the compatibilizer is maleic anhydride grafted EVA.
[0036] Preparation Example 2-3 The difference between Preparation Example 2-3 and Preparation Example 1 is that the amount of raw materials used is different, as shown in Table 1; Table 1 Raw material dosage of preparation examples 1-3 (%) Preparation Example 4 The difference between Preparation Example 4 and Preparation Example 2 is that the hydroxyl-containing toughening agent is silane-PEG-hydroxyl.
[0037] Preparation Example 5 The difference between Preparation Example 5 and Preparation Example 2 is that the hydroxyl-containing toughening agent is composed of branched hydroxyl polyester and silane-PEG-hydroxyl in a weight ratio of 1:0.1.
[0038] Preparation Example 6 The difference between Preparation Example 6 and Preparation Example 2 is that the hydroxyl-containing toughening agent is composed of branched hydroxyl polyester and silane-PEG-hydroxyl in a weight ratio of 1:0.5.
[0039] Preparation Example 7 The difference between Preparation Example 7 and Preparation Example 6 is that the polysiloxane derivative is methacrylate mono-terminated dimethyl polysiloxane.
[0040] Preparation Example 8 The difference between Preparation Example 8 and Preparation Example 6 is that the polysiloxane derivative is composed of methacrylate mono-terminated dimethyl polysiloxane and aminopropyl di-terminated polydimethyl polysiloxane in a weight ratio of 1:1.
[0041] Preparation Example 9 The difference between Preparation Example 9 and Preparation Example 6 is that the polysiloxane derivative is composed of methacrylate mono-terminated dimethyl polysiloxane and aminopropyl di-terminated polydimethyl siloxane in a weight ratio of 1:3.
[0042] Preparation Comparative Example Preparation Comparative Example 1 The difference between Preparation Comparative Example 1 and Preparation Example 1 is that the hydroxyl-containing toughening agent is replaced by TPU in equal amount.
[0043] Preparation Comparative Example 2 The difference between Preparation Comparative Example 2 and Preparation Example 1 is that an equal amount of N,N′-(4-methyl-1,3-phenylene)bismaleimide is replaced by TPU.
[0044] Preparation Comparative Example 3 The difference between Preparation Comparative Example 3 and Preparation Example 1 is that the polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer is replaced by TPU in equal amounts.
[0045] Preparation Comparative Example 4 The difference between Preparation Comparative Example 4 and Preparation Example 1 is that an equal amount of the polysiloxane derivative is replaced by TPU. Example
[0046] Example 1 A method for forming an electronic watchband with a buckle structure comprises the following steps: 1) embedding a material 1 in a jig, the material being a nail button 11 and a head particle 12, injecting a molten TPU at a temperature of 170° C. into a mold through an injection device, cooling to 30° C. to completely solidify the TPU, and obtaining a TPU body 2, wherein a nail button 11 is embedded at one end of the TPU body, and a head particle 12 is embedded at the other end, and two symmetrically arranged ring buckle connecting parts 21 are formed on the side of one side of the TPU body 2; 2) Place a sliding block between the two loop connection parts 21, inject molten TPU at a temperature of 170°C again, cool to 30°C, and completely solidify the TPU to form a loop 3 on the TPU body, and the two ends of the loop 3 are respectively connected to the two loop connection parts 21, then take out the sliding block, remove the burrs, and obtain an electronic watch strap with a loop structure 4. The electronic watch strap with a loop structure 4 can refer to Figure 1 .
[0047] Example 2-14 The difference between Example 2-14 and Example 1 is that: TPU is a modified TPU, and the specific source of the modified TPU is shown in Table 2; Table 2 Sources of modified TPU of Examples 2-14 Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that a one-time molding process is adopted, which is as follows: The material parts are nail buckles and head particles embedded in the fixture, and the TPU in a molten state at a temperature of 170°C is injected into the mold through an injection device, and cooled to 30°C to completely solidify the TPU to obtain a TPU body. A nail buckle is embedded at one end of the TPU body, and a head particle is embedded at the other end. A buckle is formed on the side of one side of the TPU body, and then the slider is taken out to obtain an electronic watch strap with a buckle structure.
[0048] Performance testing Detection method / test method Surface integrity: Observe whether the surface of the electronic watch strap with a buckle structure has scratches, wear, cracks, etc. If any of the above problems occur, it is unqualified.
[0049] The connection stability between the ring and the TPU body: The TPU body is completely fixed on the plane of the experimental table, and pulled with a force of 30kg for 1min. When the ring appears and breaks, record the corresponding fracture position and record it as a pulling force of 30kg; if there is no break, increase the pulling force by 1kg each time until a break occurs, record the corresponding pulling force and the corresponding fracture position; when the pulling force is 60kg and no break occurs, record it as a pulling force greater than 60kg. The thickness of the TPU body of this application is 2mm, the width of the connection between the ring and the ring connection part is 4mm, the average thickness is 0.8mm, the height of the ring connection part is 1mm, and the height from the bottom of the ring to the surface of the TPU body is 2.5mm.
[0050] Tensile strength and elongation at break: The TPU in Examples 1-14 and Comparative Example 1 was heated to 170° C. to be melted and placed in a mold, and then cooled to form a test sample. The test sample had a thickness of 1.5 mm, and the tensile strength and elongation at break were tested according to the test method ASTM D412.
[0051] The above experiments are shown in Table 2. Table 2 Experimental data of Examples 1-14 and Comparative Example 1 Combining Example 1 and Comparative Example 1 and Table 2, it can be seen that the indentation occurs in Comparative Example 1, but not in Example 1, and the breaking tensile force of Comparative Example 1 is consistent with the breaking tensile force of the embodiment, indicating that better performance can be obtained through the preparation process of the present application, so that the strap has better aesthetics and quality.
[0052] By comparing Example 1 and Example 2 and combining with Table 2, it can be seen that the tensile strength and elongation at break of Example 2 are higher than those of Example 1, and no end breakage occurs when the tensile force reaches 60 kg, indicating that the modified TPU prepared in this application has better comprehensive performance.
[0053] By comparing Example 2 with Examples 11-14 and combining with Table 2, it can be seen that the tensile strength and elongation at break of Example 2 are higher than those of Examples 11-14, and no end breakage occurs when the tensile force reaches 60 kg, indicating that the modified TPU prepared in this application has better comprehensive performance.
[0054] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.
Claims
1. A method for forming an electronic watchband with a buckle structure, characterized in that: The following steps are involved: 1) The material is placed in a fixture, and molten TPU is injected to solidify the TPU to obtain a TPU body, on which the embedded material is fixed, and two symmetrically arranged ring buckle connecting parts are formed on the side of one side of the TPU body; 2) Place a sliding block between the two buckle connecting parts, inject TPU again, solidify it, form a buckle on the top of the TPU body, and connect the two ends of the buckle to the two buckle connecting parts respectively, then take out the sliding block to obtain an electronic watch strap with a buckle structure.
2. The method for forming an electronic watchband with a buckle structure according to claim 1, characterized in that: The step 2) also includes removing burrs; the specific process is as follows: A sliding block is placed between the two buckle connecting parts, and TPU is injected again and solidified to form a buckle on the TPU body, and the two ends of the buckle are respectively connected to the two buckle connecting parts. Then the sliding block is taken out and the burrs are removed to obtain an electronic watch strap with a buckle structure.
3. The method for forming an electronic watch band with a buckle structure according to claim 1, characterized in that: The TPU is a modified TPU, and the modified TPU is composed of the following raw materials in percentage by weight: TPU78-90% Contains 0.1-1% hydroxy toughening agent N,N'-(4-methyl-1,3-phenylene)bismaleimide 0.5-1.5% Polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer 1-3% Polysiloxane derivatives 1-3% Filler 3-10% Catalyst 0.01-0.05% The balance is compatibilizer.
4. The method for forming an electronic watchband with a buckle structure according to claim 2, characterized in that: The hydroxyl-containing toughening agent is branched hydroxyl polyester and / or silane-PEG-hydroxyl.
5. The method for forming an electronic watch band with a buckle structure according to claim 3, characterized in that: The hydroxyl-containing toughening agent is composed of branched hydroxyl polyester and silane-PEG-hydroxyl in a weight ratio of 1: (0.1-0.5).
6. The method for forming an electronic watch band with a buckle structure according to claim 2, characterized in that: The polysiloxane derivative is methacrylate mono-terminated dimethyl polysiloxane and / or aminopropyl di-terminated polydimethyl polysiloxane.
7. The method for forming an electronic watch band with a buckle structure according to claim 5, characterized in that: The polysiloxane derivative is composed of methacrylate mono-terminated dimethyl polysiloxane and aminopropyl di-terminated polydimethyl polysiloxane in a weight ratio of 1:(1-3).
8. The method for forming an electronic watchband with a buckle structure according to claim 1, characterized in that: The filler is porous silica aerogel.
9. Improve wear resistance and surface lubricity to avoid scratching the TPU surface when removing the slider The method for forming an electronic watchband with a buckle structure according to claim 1 is characterized in that: The compatibilizer is one or more of maleic anhydride grafted EVA, maleic anhydride grafted HMA, and maleic anhydride grafted EMA.
10. A method for forming an electronic watchband with a buckle structure according to any one of claims 3 to 9, characterized in that: The modified TPU is prepared by the following method: According to weight percentage, a hydroxyl-containing toughening agent, N,N'-(4-methyl-1,3-phenylene) bismaleimide, polyethylene oxide-polypropylene oxide-polyethylene oxide block copolymer, a polysiloxane derivative, a filler, a catalyst and a compatibilizer are weighed and mixed evenly, heated to melt, and then TPU is added, and the mixture is fused and mixed evenly to obtain a modified TPU.