Secondary molding structure and method for bottle cap of plastic bottle

Abstract

The present application relates to the technical field of plastic bottle cap preparation, and particularly relates to a secondary forming structure and method of a plastic bottle cap, which comprises a bottle cap body, a fixing ring, a connecting sheet and a tear-off strip, the connecting sheet is arranged on one side of the bottle cap body and is used for connecting the bottle cap body and the fixing ring, one side of the bottle cap body opposite to the fixing ring is provided with a first connecting groove, one side of the fixing ring opposite to the first connecting groove is provided with a second connecting groove, the tear-off strip is provided with a first embedding end and a second embedding end at two ends respectively, the first embedding end is embedded in the first connecting groove, and the second embedding end is embedded in the second connecting groove; the tear-off strip comprises a forming inner layer, a fiber strip and a forming outer layer, and the fiber strip is covered by the forming outer layer and the forming inner layer through secondary injection molding. The fiber strip is covered on the outer diameter of the forming inner layer, which not only enhances the impact resistance and wear resistance of the bottle cap, but also prevents the tear-off strip from being broken during the tearing process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic bottle cap preparation, in particular to a plastic bottle cap secondary forming structure and method. BACKGROUND

[0002] Plastic bottle caps are commonly used packaging forms for bottles, cans and barrels, and are more widely used in the fields of beverages, chemicals, medicines, etc. According to their use, plastic bottle caps can be divided into breathable plastic caps and non-breathable plastic caps. Breathable plastic caps are usually used for products that need to be vented, such as carbonated beverage bottles; while non-breathable plastic caps are mainly used for products that need to maintain airtightness, such as mineral water, fruit juice, etc. The main raw material of plastic bottle caps is polyolefin, such as polypropylene (PP), high-density polyethylene (HDPE), etc. These raw materials have excellent physical and chemical properties, which can meet the requirements of bottle caps for strength, heat resistance, chemical corrosion resistance, etc.

[0003] The preparation process of plastic bottle caps mainly includes raw material preparation, pretreatment, plasticization, forming, post-treatment, etc. However, the existing plastic bottle caps prepared in the actual use have poor stability, especially the bottle caps with tear-off strips, which are prone to breakage, so new improvements need to be made to the existing plastic bottle cap preparation. SUMMARY

[0004] To solve the above problems, the present application coats a fiber strip on the outer diameter of the inner layer of the bottle cap, which not only enhances the impact resistance and wear resistance of the bottle cap, but also prevents the tear-off strip from breaking during the tearing process.

[0005] The technical solution adopted by the present application is: a plastic bottle cap secondary forming structure, comprising a bottle cap body, a fixing ring, a connecting piece and a tear-off strip, the inner diameter of the bottle cap body is provided with a sealing connection part, the sealing connection part is used to connect the bottle mouth of a plastic bottle, the connecting piece is arranged on one side of the bottle cap body and is used to connect the bottle cap body and the fixing ring, the opposite side of the bottle cap body and the fixing ring is provided with a first connecting groove, the opposite side of the fixing ring and the first connecting groove is provided with a second connecting groove, the tear-off strip connects the bottle cap body and the fixing ring through secondary forming, the two ends of the tear-off strip are respectively provided with a first embedding end and a second embedding end, the first embedding end is embedded in the first connecting groove, and the second embedding end is embedded in the second connecting groove, so that the tear-off strip connects the bottle cap body and the fixing ring; the tear-off strip comprises a forming inner layer, a fiber strip and a forming outer layer, and the fiber strip is covered by the forming outer layer and the forming inner layer through secondary injection molding.

[0006] Further improvement of the above scheme is that the bottle cap body is integrally injection molded with the fixing ring through a connecting piece, two ends of the connecting piece are respectively provided with a first flat part and a second flat part, the first flat part is used for connecting the bottle cap body, and the second flat part is used for connecting the fixing ring.

[0007] Further improvement of the above scheme is that the bottle mouth further comprises a bottle cap connecting part and a fixing connecting part, the bottle cap connecting part is used for mounting the bottle cap body, and the fixing connecting part is used for mounting the fixing ring, the bottle cap connecting part is provided with a sealing fitting part, and the sealing fitting part is used for fitting the sealing connecting part to seal the bottle mouth.

[0008] Further improvement of the above scheme is that the sealing connecting part is a sealing connecting buckle, and the sealing fitting part is a sealing connecting buckle groove; the sealing connecting buckle comprises a leading-in section, a clamping section and a sealing connecting section, the leading-in section is used for guiding the sealing fitting part towards the clamping section, the clamping section is used for clamping on the sealing connecting buckle groove, and the sealing connecting section is used for abutting one side of the sealing buckle groove.

[0009] Further improvement of the above scheme is that a metal sheet is pre-embedded in the connecting piece, the metal sheet is covered by injection molding, one end of the metal sheet extends to the first flat part, and the other end of the metal sheet extends to the second flat part.

[0010] Further improvement of the above scheme is that the metal sheet is a memory metal sheet, the normal temperature state of the memory metal sheet is U-shaped, and the high temperature state of the memory metal sheet is flat.

[0011] Further improvement of the above scheme is that the tear strip is provided with a placing groove, and the fiber strip is arranged in the placing groove; one end of the tear strip is provided with a tearing handle, one end of the placing groove is communicated to the tearing handle, and one end of the fiber strip extends to the tearing handle.

[0012] Further improvement of the above scheme is that a plurality of through holes are arranged on the fiber strip, and the through holes are connected between the shaped inner layer and the shaped outer layer.

[0013] A bottle cap secondary forming method, comprising the bottle cap secondary forming structure of the plastic bottle.

[0014] The bottle cap secondary forming method is implemented by a secondary forming device, which comprises a conveying line, a forming die, a pre-embedding mechanism, an injection molding mechanism, a pre-demolding mechanism, a primary forming mechanism, a fiber tape covering mechanism, and a secondary forming mechanism; the forming die is arranged on the conveying line, which is used to drive the forming die to pass through the pre-embedding mechanism, the injection molding mechanism, the pre-demolding mechanism, the primary forming mechanism, the fiber tape covering mechanism, and the secondary forming mechanism in sequence; the forming die is provided with a bottle cap forming groove and a fixing groove, and an injection molding connecting groove is arranged between the fixing groove and the bottle cap forming groove.

[0015] The bottle cap secondary forming method comprises the following steps:

[0016] Step S1, metal piece pre-embedding: the forming die is conveyed on the conveying line, is positioned on the conveying line when entering the pre-embedding mechanism, and then the pre-embedding mechanism is used to pre-embed the metal sheet on the injection molding connecting groove, which is provided with a positioning step for positioning the metal sheet;

[0017] Step S2, injection molding: after the pre-embedding of the metal sheet is completed, the forming die is conveyed to the injection molding mechanism by the conveying line, the injection molding mechanism closes the forming die, and after the closing, the forming die is injection molded to form the bottle cap body, the fixing ring, and the connecting piece on the forming die, the connecting piece covers the metal sheet, and the forming die is preheated during injection molding, so that the metal sheet becomes flat after being subjected to high temperature, and the metal sheet is covered by the connecting piece after injection molding;

[0018] Step S3, fixing ring demolding: after the injection molding is completed, the conveying line conveys the forming die to the pre-demolding mechanism, and the pre-demolding mechanism is used to demold the fixing ring, at this time, the metal sheet cools down during the conveying process and restores to a U-shaped shape after cooling, so that the fixing ring is opposite to the bottle body of the bottle cap;

[0019] Step S4, primary forming: after the demolding of the fixing ring is completed, the forming die is conveyed to the primary forming mechanism by the conveying line, the primary forming mechanism is provided with a primary die closing assembly, the forming die is closed by the primary die closing assembly, and then injection molding is performed to injection mold an inner layer between the bottle cap body and the fixing ring, two ends of the inner layer form a first embedding end and a second embedding end, the first embedding end is embedded in the first connecting groove, and the second embedding end is embedded in the second connecting groove;

[0020] Step S5, fiber tape covering: after the injection molding of the inner layer by the primary forming mechanism is completed, the forming die is conveyed toward the fiber tape covering mechanism by the conveying line, and the fiber tape covering mechanism covers a fiber tape on the outer diameter of the inner layer;

[0021] Step S6, secondary molding: the secondary molding mechanism is provided with a secondary mold closing assembly, after the fiber belt is covered, the secondary mold closing assembly is closed by the secondary molding mechanism, then injection molding is carried out, so that the outer layer is molded, and after cooling and shaping, the preparation of the bottle cap is completed.

[0022] Further improvement of the above scheme is that a plurality of positioning assemblies are arranged on the conveying line, and the positioning assemblies are used for positioning the molding mold, so that the corresponding injection molding mechanism, pre-embedding mechanism, pre-demolding mechanism, primary molding mechanism, pre-demolding mechanism and secondary molding mechanism are positioned during processing.

[0023] Further improvement of the above scheme is that the pre-embedding mechanism is manual pre-embedding or automatic pre-embedding, and the pre-embedding mechanism comprises a feeding disc and an automatic material taking manipulator, the feeding disc is used for metal sheet feeding, and the material taking manipulator is used for grabbing the metal sheet from the feeding disc and then placing the metal sheet on the molding mold.

[0024] Further improvement of the above scheme is that the injection molding mechanism comprises an injection molding mold, an injection molding assembly and an injection molding mold closing driving assembly, the injection molding mold closing driving assembly is used for driving the injection molding mold to close with the molding mold, and after closing, the injection molding assembly is used for injection molding on the molding mold.

[0025] Further improvement of the above scheme is that the pre-demolding mechanism comprises a pre-demolding support, a pre-demolding driving assembly, a pre-demolding pressing assembly and a pre-demolding material taking assembly, the pre-demolding pressing assembly and the pre-demolding material taking assembly are arranged on the pre-demolding driving assembly, and the pre-demolding driving assembly is arranged on the pre-demolding support; the pre-demolding material taking assembly is used for fixing the ring to take the material from the molding mold.

[0026] Further improvement of the above scheme is that the primary molding mechanism comprises a first molding driving module and a first molding injection molding module, the driving end of the first molding driving module is connected with the primary mold closing assembly, and the first molding injection molding module is arranged on the primary mold closing assembly.

[0027] Further improvement of the above scheme is that the fiber belt covering mechanism comprises a covering fixing roller, a covering fixing frame and a covering driving module, the covering fixing roller is arranged on the covering fixing frame, the covering driving module is used for driving the covering fixing frame to move towards the molding mold, and the covering fixing frame is used for fixing the fiber belt.

[0028] Further improvement of the above scheme is that the secondary molding mechanism comprises a second molding driving module and a second molding injection molding module, the driving end of the second molding driving module is connected with the secondary mold closing assembly, and the second molding injection molding module is arranged on the secondary mold closing assembly.

[0029] The beneficial effects of the present application are:

[0030] Compared with the existing bottle cap, the setting of the bottle cap body and the sealing connecting part of the application ensures the tight connection and effective sealing of the plastic bottle mouth. The sealing connecting part is specially designed to form a good fit with the bottle mouth, effectively preventing liquid leakage and ensuring the sealing performance of the product. Not only does it prolong the shelf life of the product, but it also avoids environmental pollution and inconvenience to consumers caused by leakage. Secondly, the innovative use of the connecting piece and the fixing ring further enhances the stability and reliability of the bottle cap. The connecting piece serves as a bridge between the bottle cap body and the fixing ring, and through reasonable layout and structural design, the connection between the two is more secure. The presence of the fixing ring provides additional support and protection, effectively preventing the bottle cap from falling off or being damaged during transportation or use due to external forces. This design not only improves the overall strength of the bottle cap, but also provides consumers with a more reassuring user experience. The introduction of the tear strip is a highlight of this structure. Through the secondary molding technology, the tear strip tightly connects the bottle cap body and the fixing ring together, ensuring the firmness of the connection and making it easy for users to separate when needed. The two ends of the tear strip are respectively embedded in the first and second connecting grooves, making the tearing process smoother and less likely to break. At the same time, the material and structural design of the tear strip also fully considers the user's operation experience, ensuring the comfort and convenience of the tearing process. In addition, the internal structure of the tear strip is composed of a molded inner layer, a fiber strip and a molded outer layer, and the fiber strip is tightly covered through secondary injection molding technology. Not only does it improve the overall strength and toughness of the tear strip, but also makes it have good wear resistance and tear resistance. The addition of the fiber strip further enhances the tensile strength and impact resistance of the tear strip, allowing the bottle cap to maintain structural integrity when subjected to external impact. The application realizes the tight connection of the bottle cap and the bottle mouth, the stable and reliable structure, and the convenient and comfortable operation of the user. These technical effects not only improve the market competitiveness and brand value of the product, but also provide consumers with a safer, more convenient and efficient user experience.

[0031] The secondary molding method for bottle caps involves precisely embedding metal sheets in the injection connection groove of the molding die and using positioning steps to ensure accurate placement of the metal sheets, providing a solid foundation for subsequent injection molding. This step not only enhances the structural strength of the bottle cap but also ensures a tight bond between the metal parts and the plastic components, improving overall durability and sealing performance. Preheating the molding die before injection molding ensures the embedded metal sheets are flat at high temperatures, facilitating even coverage by the connecting piece during injection and effectively preventing deformation of the metal sheets during cooling that could affect the bottle cap quality. Simultaneously, this step ensures uniform distribution and rapid cooling of the injection molding material, improving the precision and efficiency of bottle cap molding. A pre-demolding mechanism enables early demolding of the retaining ring, simplifying subsequent processing and utilizing the U-shaped recovery characteristic of the metal sheets after cooling to automatically adjust the relative position of the retaining ring and the bottle cap body, ensuring the stability and aesthetics of the bottle cap structure. In the primary molding stage, a primary mold closing assembly precisely closes the molding die, and an inner layer is injection molded between the bottle cap body and the retaining ring, enhancing the overall structural strength of the bottle cap. The first and second embedded ends formed at both ends of the inner layer are respectively embedded in the first and second connecting grooves, further enhancing the structural stability and connection reliability. A fiber tape is wrapped around the outer diameter of the molded inner layer, which not only enhances the cap's impact resistance and abrasion resistance but also prevents the tape from breaking during tearing. The secondary molding mechanism uses a secondary mold-closing assembly to perform injection molding, forming the outer layer of the cap and ensuring the smoothness and aesthetics of the cap surface. Simultaneously, the molding of the outer layer further strengthens the overall structure of the cap, improving its resistance to deformation and service life. Attached Figure Description

[0032] Figure 1 This is a three-dimensional schematic diagram of the secondary molding structure of the bottle cap of the plastic bottle of the present invention;

[0033] Figure 2 for Figure 1 An exploded view of the secondary molding structure of the cap of a plastic bottle;

[0034] Figure 3 for Figure 1 A top view of the secondary molding structure of the bottle cap of a medium-sized plastic bottle;

[0035] Figure 4 for Figure 3 Sectional view of AA;

[0036] Figure 5 for Figure 4 Enlarged diagram of point A in the diagram;

[0037] Figure 6 for Figure 1 A schematic diagram of another embodiment of the secondary molding structure for the cap of a plastic bottle;

[0038] Figure 7 For Figure 1 Preparation flow diagram of the secondary molding structure of the bottle cap of the plastic bottle;

[0039] Figure 8 For the structure diagram of the secondary molding equipment of the application;

[0040] Figure 9 For Figure 8 The top view schematic diagram of the secondary molding equipment;

[0041] Figure 10 For Figure 8 The three-dimensional schematic diagram of another perspective of the secondary molding equipment;

[0042] Figure 11 For Figure 10 The enlarged schematic diagram of A in the application;

[0043] Figure 12 For Figure 10 The enlarged schematic diagram of B in the application;

[0044] Figure 13 The secondary molding process flow chart of the plastic bottle cap.

[0045] Figure legend: bottle cap body 10, sealing connection part 101, lead-in section 1011, clamping section 1012, sealing connection section 1013, first connecting groove 102, fixing ring 20, second connecting groove 201, connecting piece 30, first flat part 301, metal sheet 303, second flat part 302, tear-off strip 40, first embedded end 401, second embedded end 402, molded inner layer 403, fiber strip 404, molded outer layer 405, tear-off handle 406, bottle mouth 50, bottle cap connecting part 501, fixed connecting part 502, sealing matching part 503;

[0046] Conveying line 1, positioning assembly 11, molding die 2, pre-embedding mechanism 3, feeding tray 31, automatic material taking manipulator 32, injection mechanism 4, injection mold 41, injection assembly 42, injection mold closing driving assembly 43, pre-ejection mechanism 5, pre-ejection support 51, pre-ejection driving assembly 52, pre-ejection pressing assembly 53, pre-ejection material taking assembly 54, primary molding mechanism 6, first molding driving module 61, first molding injection module 62, primary mold closing assembly 63, fiber strip coating mechanism 7, coating fixing roller 71, coating fixing frame 72, coating driving module 73, secondary molding mechanism 8, second molding driving module 81, second molding injection module 82, secondary mold closing assembly 83. DETAILED DESCRIPTION

[0047] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0048] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0049] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Figures 1 to 13As shown, in an embodiment of the present application, a plastic bottle cap secondary forming structure is disclosed, which comprises a cap body 10, a fixing ring 20, a connecting piece 30 and a tear-off strip 40. The inner diameter of the cap body 10 is provided with a sealing connection part 101, which is used to connect the bottle mouth of the plastic bottle. The connecting piece 30 is arranged on one side of the cap body 10 and is used to connect the cap body 10 and the fixing ring 20. The opposite side of the cap body 10 and the fixing ring 20 is provided with a first connecting groove 102. The opposite side of the fixing ring 20 and the first connecting groove 102 is provided with a second connecting groove 201. The tear-off strip 40 connects the cap body 10 and the fixing ring 20 through secondary forming. The two ends of the tear-off strip 40 are respectively provided with a first embedded end 401 and a second embedded end 402. The first embedded end 401 is embedded in the first connecting groove 102, and the second embedded end 402 is embedded in the second connecting groove 201, so that the tear-off strip 40 connects the cap body 10 and the fixing ring 20. The tear-off strip 40 comprises a forming inner layer 403, a fiber strip 404 and a forming outer layer 405. The fiber strip 404 is covered by the forming outer layer 405 and the forming inner layer 403 through secondary injection molding. In this embodiment, the cap body 10 and the sealing connection part 101 ensure the tight connection and effective sealing of the bottle mouth of the plastic bottle. The sealing connection part 101 is specially designed to form a good fit with the bottle mouth, effectively preventing liquid leakage and ensuring the sealing performance of the product. Not only does it prolong the shelf life of the product, but it also avoids environmental pollution and inconvenience to consumers caused by leakage. Secondly, the innovative use of the connecting piece 30 and the fixing ring 20 further enhances the stability and reliability of the cap. The connecting piece 30 serves as a bridge between the cap body 10 and the fixing ring 20, and through reasonable layout and structural design, the connection between the two is more secure. The presence of the fixing ring 20 provides additional support and protection, effectively preventing the cap from falling off or being damaged due to external forces during transportation or use. This design not only improves the overall strength of the cap, but also provides consumers with a more reassuring user experience. The introduction of the tear-off strip 40 is a highlight of this structure. Through the secondary forming technology, the tear-off strip 40 tightly connects the cap body 10 and the fixing ring 20 together, ensuring the firmness of the connection and making it easy for users to separate when needed. The two ends of the tear-off strip 40 are respectively embedded in the first connecting groove 102 and the second connecting groove 201, which makes the tearing process smoother and less likely to break. At the same time, the material and structural design of the tear-off strip 40 also fully considers the user's operation experience, ensuring the comfort and convenience of the tearing process. In addition, the internal structure of the tear-off strip 40 is composed of a forming inner layer 403, a fiber strip 404 and a forming outer layer 405, which are tightly covered by the secondary injection molding technology. Not only does it improve the overall strength and toughness of the tear-off strip 40, but it also makes it have good wear resistance and tear resistance.The addition of the fiber band 404 further enhances the tensile strength and impact resistance of the tear-off band 40, enabling the bottle cap to maintain structural integrity when subjected to external force impact. The present application achieves a tight connection between the bottle cap and the bottle opening, structural stability and reliability, and user-friendly and comfortable operation. These technical effects not only enhance the market competitiveness and brand value of the product, but also provide consumers with a safer, more convenient, and efficient use experience.

[0050] The bottle cap body 10 is integrally injection molded with the fixing ring 20 through the connecting piece 30, both ends of the connecting piece 30 are respectively provided with a first flat part 301 and a second flat part 302, the first flat part 301 is used to connect the bottle cap body 10, and the second flat part 302 is used to connect the fixing ring 20. Specifically, a metal sheet 303 is pre-embedded in the connecting piece 30, the connecting piece 30 covers the metal sheet 303 by injection molding, one end of the metal sheet 303 extends to the first flat part 301, and the other end extends to the second flat part 302; the metal sheet 303 is a memory metal sheet 303, the normal temperature state of the memory metal sheet 303 is U-shaped, and the high temperature state is flat. In this embodiment, the first flat part 301 and the second flat part 302 are respectively arranged at both ends of the connecting piece 30, which not only ensures the stable connection between the bottle cap body 10 and the fixing ring 20, but also greatly improves the overall structural strength. More importantly, the memory metal sheet 303 assumes a U-shaped shape at normal temperature, which provides the connecting piece 30 with good elasticity and toughness, enabling the bottle cap to maintain structural stability and integrity when subjected to external force. During the high-temperature injection molding process, the memory metal sheet 303 becomes flat, which is convenient for being covered by plastic, thereby achieving perfect fusion of metal and plastic. In addition, this feature of the memory metal sheet 303 enables the bottle cap to quickly recover to the preset shape after molding, further enhancing its durability and reliability. In general, this secondary molding structure of the bottle cap improves the overall performance of the bottle cap through innovative design of the connecting piece 30 and application of the memory metal sheet 303, and meets the market demand for high-quality and reliable bottle cap products.

[0051] The bottle mouth 50 comprises a bottle cap connecting part 501 for mounting the bottle cap body 10 and a fixed connecting part 502 for mounting the fixed ring 20. The bottle cap connecting part 501 is provided with a sealing matching part 503 for matching the sealing connecting part 101 to seal the bottle mouth 50. Specifically, the sealing connecting part 101 is a sealing connecting buckle, and the sealing matching part 503 is a sealing connecting buckle groove. The sealing connecting buckle comprises a leading-in section 1011 for guiding the sealing matching part 503 towards the clamping section 1012, the clamping section 1012 for clamping on the sealing connecting buckle groove, and the sealing connecting section 1013 for abutting one side of the sealing connecting buckle groove. In this embodiment, the precise butt joint of the bottle cap connecting part 501 and the bottle cap body 10 ensures the stable installation of the bottle cap and effectively prevents the liquid leakage problem caused by the loose bottle cap. At the same time, the fixed connecting part 502 provides a reliable support point for the installation of the fixed ring 20, further enhancing the sealing and stability of the bottle cap. The ingenious matching of the sealing matching part 503 and the sealing connecting part 101, especially the precise design of the sealing connecting buckle and the sealing connecting buckle groove, makes the bottle mouth 50 reach a higher sealing standard in the sealing process. The guiding effect of the leading-in section 1011 enables the sealing matching part 503 to smoothly enter the clamping section 1012, and the clamping function of the clamping section 1012 ensures the tight connection between the sealing connecting part 101 and the sealing matching part 503. In addition, the abutting design of the sealing connecting section 1013 effectively prevents the intrusion of external air or liquid, thereby ensuring the freshness and safety of the liquid in the bottle. This design not only improves the overall performance of the bottle cap, but also prolongs the shelf life of the product, providing consumers with a more superior use experience.

[0052] The tear-off strip 40 is provided with a placement groove, and the fiber strip 404 is arranged in the placement groove. One end of the tear-off strip 40 is provided with a tear-off handle 406, one end of the placement groove is communicated to the tear-off handle 406, and one end of the fiber strip 404 extends to the tear-off handle 406. Specifically, the fiber strip 404 is provided with a plurality of through holes, and the shaped inner layer 403 and the shaped outer layer 405 are connected through the through holes. In this embodiment, by skillfully arranging the fiber strip 404 in the placement groove of the tear-off strip 40, not only the compactness and stability of the structure are ensured, but also the convenience of user operation is greatly improved. The design of the tear-off handle 406 at one end of the tear-off strip 40 enables the user to easily grasp and tear off the tear-off strip 40, thereby realizing quick access or adjustment of the internal structure of the bottle cap. The plurality of through holes arranged on the fiber strip allow the shaped inner layer 403 and the shaped outer layer 405 to be firmly connected, ensuring the structural integrity and sealing performance of the bottle cap during the secondary molding process. At the same time, the existence of the through holes also facilitates the traction or fixation of the internal structure of the bottle cap by the fiber strip 404 when necessary, improving the flexibility and controllability in the processing process.

[0053] The bottle cap secondary molding method comprises a bottle cap secondary molding structure of a plastic bottle.

[0054] Referring to Figures 8 to 13 As shown in the figure, the bottle cap secondary molding method is implemented by a secondary molding device, which comprises a conveying line 1, a molding die 2, a pre-embedding mechanism 3, an injection molding mechanism 4, a pre-ejection mechanism 5, a primary molding mechanism 6, a fiber strip wrapping mechanism 7, and a secondary molding mechanism 8. The molding die 2 is arranged on the conveying line 1, and the conveying line 1 is used to drive the molding die 2 to pass through the pre-embedding mechanism 3, the injection molding mechanism 4, the pre-ejection mechanism 5, the primary molding mechanism 6, the fiber strip wrapping mechanism 7, and the secondary molding mechanism 8 in sequence. The molding die 2 is provided with a bottle cap molding groove and a fixing groove, and the fixing groove is provided with an injection molding connecting groove between the bottle cap molding groove;

[0055] The bottle cap secondary molding method comprises the following steps:

[0056] Step S1, metal piece pre-embedding: the molding die 2 is conveyed on the conveying line 1, positioned on the conveying line 1 when entering the pre-embedding mechanism 3, and then the pre-embedding mechanism 3 is used to pre-embed the metal sheet on the injection molding connecting groove, which has a positioning step for positioning the metal sheet;

[0057] Step S2, injection molding: after the metal sheet is pre-embedded, the molding mold 2 is transported to the injection mechanism 4 through the conveying line 1, the injection mechanism 4 closes the molding mold 2, and the molding mold 2 is injection molded after being closed to form the bottle cap body, the fixing ring and the connecting sheet on the molding mold 2, the connecting sheet covers the metal sheet, and the molding mold 2 is preheated during injection molding to make the metal sheet flat after being heated to a high temperature, and the metal sheet is covered through the connecting sheet after injection molding;

[0058] Step S3, fixing ring demolding: after the injection molding is completed, the molding mold 2 is transported by the conveying line 1 and transported to the pre-demolding mechanism 5, the pre-demolding mechanism 5 is used for demolding the fixing ring, at this time the metal sheet is cooled in the conveying process, and after cooling, the metal sheet returns to the U-shaped shape, so that the fixing ring is opposite to the bottle body of the bottle cap;

[0059] Step S4, one-time molding: after the fixing ring demolding is completed, the molding mold 2 is transported to the one-time molding mechanism 6 through the conveying line 1, the one-time molding mechanism 6 is provided with a one-time closing assembly 63, the molding mold 2 is closed through the one-time closing assembly 63, and then injection molding is performed to injection mold the inner layer between the bottle cap body and the fixing ring, the two ends of the inner layer form a first embedding end and a second embedding end, the first embedding end is embedded in the first connecting groove, and the second embedding end is embedded in the second connecting groove;

[0060] Step S5, fiber tape covering: after the injection molding of the inner layer by the one-time molding mechanism 6 is completed, the molding mold 2 is transported towards the fiber tape covering mechanism 7 through the conveying line 1, and the fiber tape covering mechanism 7 covers the fiber tape on the outer diameter of the inner layer;

[0061] Step S6, secondary molding: the secondary molding mechanism 8 is provided with a secondary closing assembly 83, after the covering of the fiber tape is completed, the secondary closing assembly 83 is closed by the secondary molding mechanism 8, and then injection molding is performed to mold the outer layer, and after molding, waiting for cooling and setting to complete the preparation of the bottle cap.

[0062] The metal sheet 303 is precisely pre-embedded on the injection molding connecting groove of the forming mold 2, and the positioning step ensures the accurate placement of the metal sheet 303, providing a solid foundation for subsequent injection molding. This step not only enhances the structural strength of the bottle cap, but also ensures the close combination of the metal part and the plastic part, improving the overall durability and sealing performance. The forming mold 2 is preheated before injection molding, so that the pre-embedded metal sheet 303 is in a flat state at high temperature, which facilitates the uniform covering of the connecting piece 30 during injection molding, effectively avoiding the problem of metal sheet 303 deformation affecting the quality of the bottle cap due to cooling. At the same time, this step also ensures the uniform distribution and rapid cooling of the injection molding material, improving the precision and efficiency of the bottle cap forming. The pre-ejection mechanism 5 realizes the early ejection of the fixing ring 20, which not only simplifies the subsequent processing process, but also takes advantage of the U-shaped characteristics of the metal sheet 303 after cooling, automatically adjusts the relative position of the fixing ring 20 and the bottle body of the bottle cap, and ensures the stability and aesthetics of the bottle cap structure. In the one-time forming stage, the one-time mold closing assembly 63 precisely closes the forming mold 2, and the inner layer 403 is injection molded between the bottle cap body 10 and the fixing ring 20, enhancing the overall structural strength of the bottle cap. The first embedded end 401 and the second embedded end 402 formed at both ends of the inner layer, respectively embedded in the first connecting groove 102 and the second connecting groove 201, further improve the stability of the structure and the reliability of the connection. The fiber band 404 is coated on the outer diameter of the formed inner layer 403, which not only enhances the impact resistance and wear resistance of the bottle cap, but also prevents the tearing of the tearing band 40 from breaking during the tearing process. The secondary forming mechanism 8 is combined and molded by the secondary mold closing assembly 83 to form the outer layer of the bottle cap, ensuring the smoothness and aesthetics of the bottle cap surface. At the same time, the formation of the outer layer further consolidates the overall structure of the bottle cap, improves its anti-deformation ability and service life.

[0063] The conveying line 1 is provided with a plurality of positioning assemblies 11 for positioning the forming mold 2 to correspond to the positioning of the injection molding mechanism 4, the pre-embedding mechanism 3, the pre-demolding mechanism 5, the primary forming mechanism 6, the pre-demolding mechanism 5, and the secondary forming mechanism 8 during processing. In this embodiment, the positioning assemblies 11 are specifically designed for precise positioning of the forming mold 2, ensuring the stability and accuracy of the mold during processing. When the mold is conveyed to the injection molding mechanism 4, the positioning assemblies 11 can quickly and accurately position the mold at the predetermined position, providing a solid foundation for injection molding. Subsequently, during the processing of the pre-embedding mechanism 3, the pre-demolding mechanism 5, and the primary forming mechanism 6, the positioning assemblies 11 continue to play a role, ensuring seamless connection and accurate conversion of the mold between each process. It is particularly important that before entering the secondary forming mechanism 8, the mold again undergoes precise adjustment by the pre-demolding mechanism 5, at which time the precision and stability of the positioning assemblies 11 are particularly important, as they ensure that the mold does not shift or deform during secondary forming, thereby greatly improving the quality and consistency of the finished bottle cap. In addition, the design of these positioning assemblies 11 also takes into account the automation and continuous production capacity of the equipment. They can efficiently cooperate with the operation of the conveying line 1 to achieve rapid and accurate positioning of the mold, thereby significantly improving the production efficiency and capacity of the bottle cap secondary forming equipment.

[0064] The pre-embedding mechanism 3 is manual or automatic pre-embedding, which includes a feeding tray 31 for feeding metal sheets 303 and an automatic taking mechanical hand 32 for grabbing metal sheets 303 from the feeding tray 31 and placing them on the forming mold 2. In this embodiment, the feeding tray 31 serves as a stable source of metal sheets 303, ensuring the continuity of the production process and avoiding production interruptions due to material shortages. Its design is reasonable and can effectively manage the storage and transportation of metal sheets 303, providing a solid foundation for subsequent forming processes. The application of the automatic taking mechanical hand 32 is a technical highlight of this pre-embedding mechanism 3. It uses advanced robotic arm technology and intelligent control systems to accurately grab metal sheets 303 from the feeding tray 31 and place them accurately on the forming mold 2. This process not only achieves a high degree of automation but also significantly improves the forming quality and consistency of the product.

[0065] The injection molding mechanism 4 includes an injection molding die 41, an injection molding assembly 42, and an injection molding clamping drive assembly 43 for driving the injection molding die 41 to clamp with the forming die 2, and after clamping, the injection molding assembly 42 is used for injection molding to the forming die 2; in this embodiment, the injection molding mechanism 4, specifically including the injection molding die 41, the injection molding assembly 42, and the injection molding clamping drive assembly 43, is applied to the bottle cap secondary forming equipment, which can significantly improve the technical effect and efficiency of bottle cap production. The precise size and shape of the injection molding die 41 ensure the high precision and consistency of the secondary formed bottle cap, which is crucial for ensuring the sealing and durability of the product. The injection molding assembly 42 is responsible for injecting molten plastic material into the mold cavity, ensuring that the material can uniformly and quickly fill the mold, thereby forming a structurally complete and smooth appearance bottle cap. The injection molding clamping drive assembly 43 plays a key role in the secondary forming process of the bottle cap. It can provide stable and powerful driving force to ensure that the injection molding die 41 accurately clamps with the forming die 2, avoiding forming defects caused by misalignment or gap of the mold. At the same time, the rapid response capability of the clamping drive assembly also shortens the mold opening and closing cycle, improving production efficiency.

[0066] The pre-ejection mechanism 5 includes a pre-ejection support 51, a pre-ejection drive assembly 52, a pre-ejection pressing assembly 53, and a pre-ejection material taking assembly 54, the pre-ejection pressing assembly 53 and the pre-ejection material taking assembly 54 are both arranged on the pre-ejection drive assembly 52, and the pre-ejection drive assembly 52 is arranged on the pre-ejection support 51; the pre-ejection material taking assembly 54 is used to fix the ring 20 from the forming die 2. In this embodiment, the pre-ejection support 51 serves as the support basis of the entire mechanism, ensuring the stable operation of each component. The pre-ejection drive assembly 52 serves as the power source, which drives the pre-ejection pressing assembly 53 and the pre-ejection material taking assembly 54 to complete their respective tasks through precise control. The pre-ejection pressing assembly 53 plays a key role in the forming process, which can ensure the stable formation of the bottle cap in the mold, prevent forming defects caused by mold gap or material flow. The pre-ejection material taking assembly 54 is specially used for taking the ring 20 from the forming die 2. The design of this assembly fully considers the structural characteristics and ejection requirements of the bottle cap, and can accurately and quickly complete the material taking action, effectively avoiding damage to the bottle cap during ejection, thereby ensuring the integrity and aesthetics of the product.

[0067] The primary molding mechanism 6 includes a first molding drive module 61 and a first molding injection module 62. The driving end of the first molding drive module 61 is connected with a primary mold assembly 63, and the first molding injection module 62 is arranged on the primary mold assembly 63. Specifically, the fiber tape covering mechanism 7 includes a covering fixed roller 71, a covering fixed frame 72, and a covering drive module 73. The covering fixed roller 71 is arranged on the covering fixed frame 72, the covering drive module 73 is used to drive the covering fixed frame 72 to move towards the molding mold 2, and the covering fixed frame 72 is used to fix the fiber tape 404. The secondary molding mechanism 8 includes a second molding drive module 81 and a second molding injection module 82. The driving end of the second molding drive module 81 is connected with a secondary mold assembly 83, and the second molding injection module 82 is arranged on the secondary mold assembly 83. In this embodiment, the primary molding mechanism 6 is precisely connected with the primary mold assembly 63 through the first molding drive module 61, which ensures the stability and accuracy of the mold during the injection molding process. The first molding injection module 62 is arranged on the primary mold assembly 63, which can efficiently inject molten plastic to form the basic shape of the bottle cap. This design not only improves the uniformity and consistency of injection molding, but also effectively reduces the molding defects caused by unstable molds, such as bubbles and shrink marks. Secondly, the introduction of the fiber tape covering mechanism 7 provides an additional reinforcing layer for the bottle cap. The combination of the covering fixed roller 71 and the covering fixed frame 72 can firmly fix the fiber tape 404, ensuring its stability and continuity during the covering process. The covering drive module 73 drives the covering fixed frame 72 to move towards the molding mold 2, realizing the precise covering of the fiber tape 404. This step not only enhances the strength and wear resistance of the bottle cap, but also gives the bottle cap a richer appearance and texture, meeting the market's demand for diversified bottle caps. Finally, the secondary molding mechanism 8 further refines the bottle cap through the close cooperation of the second molding drive module 81 and the secondary mold assembly 83. The arrangement of the second molding injection module 82 on the secondary mold assembly 83 allows molten plastic to be injected into the bottle cap again, shaping and reinforcing the bottle cap. This step not only improves the dimensional accuracy and structural stability of the bottle cap, but also effectively eliminates internal stress that may be generated during the primary molding, improving the durability and service life of the bottle cap.

[0068] The above embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A secondary molding structure for a plastic bottle cap, characterized in that: The device includes a bottle cap body, a retaining ring, a connecting piece, and a tear strip. The inner diameter of the bottle cap body has a sealing connection for connecting to the mouth of a plastic bottle. The connecting piece is located on one side of the bottle cap body and connects the bottle cap body to the retaining ring. A first connecting groove is provided on the side of the bottle cap body opposite to the retaining ring, and a second connecting groove is provided on the side of the retaining ring opposite to the first connecting groove. The tear strip connects the bottle cap body to the retaining ring through secondary molding. The tear strip has a first embedding end and a second embedding end at its two ends. The first embedding end is embedded in the first connecting groove, and the second embedding end is embedded in the second connecting groove, thus connecting the bottle cap body to the retaining ring. The tear strip includes a molded inner layer, a fiber strip, and a molded outer layer. The molded outer layer and the molded inner layer are injection molded in two stages to cover the fiber strip. The bottle cap body is integrally injection molded with a connecting piece and a fixing ring. The two ends of the connecting piece are respectively provided with a first flat part and a second flat part. The first flat part is used to connect the bottle cap body, and the second flat part is used to connect the fixing ring. It also includes a bottle mouth, which includes a cap connecting part and a fixed connecting part. The cap connecting part is used to install the cap body, and the fixed connecting part is used to install a fixing ring. The cap connecting part is provided with a sealing mating part, which is used to cooperate with the sealing connecting part to seal the bottle mouth. A metal sheet is pre-embedded in the connecting piece, and the metal sheet is encapsulated in the connecting piece by injection molding. One end of the metal sheet extends to the first flat portion and the other end extends to the second flat portion. The metal sheet is a shape memory metal sheet, which is U-shaped at room temperature and flat at high temperature. The tear strip has a placement groove, and the fiber strip is placed in the placement groove; one end of the tear strip is provided with a tear handle, one end of the placement groove is connected to the tear handle, and one end of the fiber strip extends to the tear handle.

2. The secondary molding structure for the bottle cap of the plastic bottle according to claim 1, characterized in that: The sealing connection part is a sealing connection buckle, and the sealing mating part is a sealing connection groove; the sealing connection buckle includes an inlet section, a snap-fit ​​section and a sealing connection section, the inlet section is used to guide the sealing mating part toward the snap-fit ​​section, the snap-fit ​​section is used to snap onto the sealing connection groove, and the sealing connection section is used to abut against one side of the sealing groove.

3. The secondary molding structure for the bottle cap of the plastic bottle according to claim 1, characterized in that: The fiber tape has multiple through holes, and the inner molded layer and the outer molded layer are connected through the through holes.

4. A method for secondary molding of bottle caps, characterized in that: Used to prepare the secondary molding structure of the bottle cap of the plastic bottle according to any one of claims 1 to 3; The secondary forming method for bottle caps is implemented by secondary forming equipment, which includes a conveyor line, a forming mold, a pre-embedded mechanism, an injection molding mechanism, a pre-demolding mechanism, a primary forming mechanism, a fiber tape covering mechanism, and a secondary forming mechanism. The forming mold is set on the conveyor line, which drives the forming mold to pass sequentially through the pre-embedded mechanism, the injection molding mechanism, the pre-demolding mechanism, the primary forming mechanism, the fiber tape covering mechanism, and the secondary forming mechanism. The forming mold is provided with a bottle cap forming groove and a fixing groove, and an injection connection groove is provided between the fixing groove and the bottle cap forming groove. The secondary molding method for bottle caps includes the following steps: Step S1, metal part pre-embedding: The forming mold is conveyed on the conveyor line and enters the pre-embedding mechanism. It is positioned on the conveyor line and then the pre-embedding mechanism is used to pre-embedding the metal sheet in the injection molding connection groove. The injection molding connection groove has positioning steps for positioning the metal sheet. Step S2, Injection Molding: After the metal sheet is pre-embedded, the molding die is transported to the injection molding mechanism via a conveyor line. The injection molding mechanism closes the molding die and then performs injection molding to form the bottle cap body, fixing ring, and connecting piece on the molding die. The connecting piece covers the metal sheet. During injection molding, the molding die is preheated so that the metal sheet becomes flat after encountering high temperature. After injection molding, the metal sheet is covered by the connecting piece. Step S3, Demolding of the retaining ring: After injection molding is completed, the conveyor line transports the molding mold to the pre-demolding mechanism. The pre-demolding mechanism is used to demold the retaining ring. At this time, the metal sheet is cooled during the conveying process and returns to the U-shape after cooling, so that the retaining ring is opposite to the bottle cap and bottle body. Step S4, one-time molding: After the fixing ring is demolded, the molding mold is transported to the one-time molding mechanism through the conveyor line. The one-time molding mechanism is equipped with a one-time mold closing assembly. The molding mold is closed by the one-time mold closing assembly, and then injection molding is performed to injection mold the inner layer between the bottle cap body and the fixing ring. The two ends of the molded inner layer form a first embedded end and a second embedded end. The first embedded end is embedded in the first connecting groove, and the second embedded end is embedded in the second connecting groove. Step S5, fiber tape covering: After the injection molding of the inner layer is completed by the molding mechanism, the molding mold is conveyed to the fiber tape covering mechanism through the conveyor line. The fiber tape covering mechanism covers the outer diameter of the inner layer with fiber tape. Step S6, Secondary Molding: The secondary molding mechanism is equipped with a secondary mold closing component. After the fiber tape is wrapped, the secondary molding mechanism closes the secondary mold closing component and then performs injection molding to form the outer layer. After molding, wait for cooling and solidification to complete the preparation of the bottle cap.

5. The secondary forming method for bottle caps according to claim 4, characterized in that: The conveyor line is equipped with multiple positioning components, which are used to position the forming mold so as to position it during processing by the injection molding mechanism, the pre-embedded mechanism, the pre-demolding mechanism, the primary molding mechanism, the pre-demolding mechanism, and the secondary molding mechanism. The pre-embedding mechanism can be manual or automatic. The pre-embedding mechanism includes a feeding tray and an automatic material handling robot. The feeding tray is used to feed metal sheets, and the material handling robot is used to grab the metal sheets from the feeding tray and then place them on the forming mold. The injection molding mechanism includes an injection mold, an injection assembly, and an injection mold closing drive assembly. The injection mold closing drive assembly is used to drive the injection mold and the molding mold to close together. After the mold is closed, the injection assembly is used to perform injection molding on the molding mold. The pre-demolding mechanism includes a pre-demolding bracket, a pre-demolding drive assembly, a pre-demolding clamping assembly, and a pre-demolding material removal assembly. The pre-demolding clamping assembly and the pre-demolding material removal assembly are both mounted on the pre-demolding drive assembly, and the pre-demolding drive assembly is mounted on the pre-demolding bracket. The pre-demolding material removal assembly is used to remove material from the molding die by fixing the ring.

6. The secondary forming method for bottle caps according to claim 5, characterized in that: The one-time molding mechanism includes a first molding drive module and a first molding injection module. The drive end of the first molding drive module is connected to the one-time mold closing assembly, and the first molding injection module is disposed on the one-time mold closing assembly. The fiber tape covering mechanism includes a covering fixing roller, a covering fixing frame, and a covering driving module. The covering fixing roller is disposed on the covering fixing frame, the covering driving module is used to drive the covering fixing frame to move toward the forming mold, and the covering fixing frame is used to fix the fiber tape. The secondary molding mechanism includes a second molding drive module and a second molding injection module. The drive end of the second molding drive module is connected to the secondary mold closing assembly, and the second molding injection module is mounted on the secondary mold closing assembly.

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