Iron-plastic composite crown-shaped bottle cap gradient forming process and intelligent production system

Abstract

The invention discloses an iron-plastic composite crown-shaped bottle cap gradient forming process and an intelligent production system, which belong to a substrate pretreatment process, and comprise the following steps: carrying out laser cutting forming on a tinplate strip, flocking a zirconium phosphate nano whisker enhancement layer on the surface, carrying out injection molding on microcellular foamed plastic layers on two sides of a metal framework, and compounding an antibacterial sealing material on a middle layer, a mechanical interlocking structure is formed on a metal / plastic interface through plasma activation, trapezoidal labyrinth sealing ribs with narrow upper parts and wide lower parts are injection-molded on the top, auxiliary ribs are spirally and radially arranged at 15 degrees, and a metal pretreatment module, a double-material co-injection module, an online heat treatment module and a block chain tracing system are included. According to the iron-plastic composite crown-shaped bottle cap gradient forming process and the intelligent production system, a full-bio-based degradable composite material system is adopted, petroleum-based plastic is completely replaced, a solvent-free sealing process is combined, zero harmful substance emission in the whole production process is achieved, and the requirement for circular economy development is met.

Description

Technical Field

[0001] This invention relates to the field of bottle cap processing technology, specifically to a gradient molding process and intelligent production system for iron-plastic composite crown-shaped bottle caps. Background Technology

[0002] Traditional crown-shaped bottle cap manufacturing has long relied on petroleum-based plastics, whose non-degradable nature leads to a severe environmental burden. Furthermore, chemical additives used to improve processing performance pose a migration risk, threatening product safety. While early attempts at bio-based materials offer environmental advantages, they suffer from inherent flaws that hinder practical application: insufficient thermal stability, inability to withstand conventional sterilization processes, weak mechanical properties leading to brittle fracture when the cap is opened, and melt strength defects making it difficult to form a stable cell structure.

[0003] Traditional iron-plastic composite bottle caps suffer from two types of structural defects: Interface failure occurs because the difference in thermal expansion characteristics between metals and plastics generates internal stress when the temperature changes, leading to delamination and seal mismatch. Traditional sealing structures are poorly adaptable to fluctuations in bottle opening size and are prone to leakage. Solvent-based coating processes release harmful volatile substances and have low curing efficiency.

[0004] Design motivation: In response to the aforementioned fundamental problems, this design breaks through by constructing a multi-level interface strengthening mechanism to build a micro-nano reinforcement layer on a metal substrate and forming an anchoring structure through energy field activation. Adaptive sealing topology innovative geometric configuration design enhances sealing surface tolerance; The development of clean coating technology has led to the creation of solvent-free systems that achieve efficient and environmentally friendly sealing. Summary of the Invention

[0005] The purpose of this invention is to provide a gradient molding process and intelligent production system for iron-plastic composite crown-shaped bottle caps, in order to solve the problems mentioned in the background art, such as the inability to dynamically compensate for material shrinkage during the injection molding stage, resulting in poor dimensional stability and reliance on manual sampling for quality inspection.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a gradient molding process and intelligent production system for iron-plastic composite crown-shaped bottle caps, comprising: The preparation process of bio-based composite materials involves blending polylactic acid matrix materials with compatible modified polymers, composite nano-inorganic fillers, and antibacterial functional components. The supercritical fluid microporous foaming molding process achieves lightweight closed-cell structure molding by precisely controlling the supercritical fluid injection parameters. The gradient cooling and shaping process employs a three-stage separately controlled cooling system to achieve stress balance control of the product. The solvent-free sealant continuous coating process achieves uniform coating and rapid curing of the sealing layer through electrostatic spin coating. The integrated production line architecture is a continuous production system that includes an intelligent material feeding module, a multi-station injection molding module, an online testing module, and a quality traceability system.

[0007] The core of the above technical solution includes replacing traditional petroleum-based plastics with bio-based composite materials, achieving material biodegradability through blending polylactic acid with modified polymers; innovatively introducing supercritical fluid microporous foaming technology to form a uniform closed-cell structure during melt molding to achieve lightweighting; developing a three-stage gradient cooling system to control the internal stress distribution of the product through a combination of different media and energy transfer methods; using electrostatic spin coating technology with solvent-free sealant to overcome the environmental pollution bottleneck of traditional solvent-based coating processes; and finally, constructing a fully continuous production line by integrating modules such as intelligent feeding, multi-station injection molding, and online detection.

[0008] As a preferred technical solution of the present invention, the bio-based composite material comprises, by weight, 60-80 parts of polylactic acid, 20-40 parts of maleic anhydride-grafted polyolefin, 5-10 parts of modified nanoclay, and 0.5-2 parts of plant extract microcapsules, wherein the melt index of the polylactic acid matrix is ​​5-10 g / 10 min, and the nanoclay interlayer spacing is ≥2.5 nm and has undergone organic intercalation treatment.

[0009] Using the above technical solution, this material system is based on polylactic acid (PLA). Maleic anhydride-grafted polyolefins are introduced to improve interfacial compatibility and overcome the defects of pure PLA, such as high brittleness and poor thermal stability. Nano-clay with optimized interlayer spacing enhances the material's mechanical properties, and its organic intercalation treatment significantly improves filler dispersibility. Innovative addition of plant extract microcapsules imparts antibacterial properties to the product while ensuring processing performance. This formulation design, through the synergistic effect of multiple components, enables the composite material to meet the mechanical strength and heat resistance requirements of bottle caps while maintaining biodegradability, particularly solving the industry problem of traditional bio-based materials failing to meet high-temperature sterilization requirements.

[0010] As a preferred technical solution of the present invention, in the supercritical fluid microporous foaming molding process, the supercritical CO2 injection pressure is controlled at 25-35MPa, the melt temperature is adjusted in three stages within the range of 170-200℃, the swelling ratio is maintained at 3.0-4.0:1, and a constant temperature shaping sleeve is set at the mold outlet.

[0011] By adopting the above technical solution, this technology achieves precise control of bubble nucleation and growth during the foaming process by accurately regulating the injection pressure and temperature gradient of supercritical carbon dioxide, ensuring that a uniform and dense closed-cell structure is formed inside the product; the design of adjusting the melt temperature in three stages ensures that the gas is fully dissolved and prevents the thermal degradation of the material; a constant temperature shaping device is set at the mold outlet to effectively control the dimensional stability of the foam.

[0012] As a preferred technical solution of the present invention, the gradient cooling and shaping process specifically includes: a. Level 1 air-cooling stage: wind speed 5-10m / s, temperature 15-25℃, duration 20-40 seconds; b. Secondary liquid cooling stage: Cooling medium temperature 10-20℃, immersion time 10-20 seconds; c. Third-level infrared balancing stage: Mid-wave infrared radiation is used, with a power density of 30-60W / cm² and a processing time of 5-15 seconds.

[0013] The above-mentioned technical solution employs a composite cooling method combining air cooling, liquid cooling, and infrared radiation: primary air cooling achieves rapid cooling and shaping through forced convection; secondary liquid cooling utilizes medium immersion to ensure uniform cooling of the entire product; and tertiary infrared balancing eliminates residual stress through directional radiation. This staged, multi-mode cooling scheme effectively solves the problem of product warping and deformation caused by traditional single cooling methods. It is particularly optimized for the thermal shrinkage characteristics of foamed materials, and by controlling the heat transfer rate and direction at different cooling stages, it achieves directional control of the product's microstructure, significantly improving product dimensional accuracy and shape stability.

[0014] As a preferred technical solution of the present invention, the solvent-free sealant comprises 40-50% polyvinyl chloride paste resin, 30-40% bio-based plasticizer, 2-5% surfactant, and 1-3% nano titanium dioxide, wherein the plasticizer is a citrate ester compound, and the sealant viscosity is 2000-3000 mPa·s.

[0015] Using the above technical solution, this formulation uses polyvinyl chloride paste resin as the matrix and replaces traditional phthalic acid plasticizers with bio-based plasticizers, fundamentally preventing the migration of harmful substances. The addition of surfactants improves the rheological properties of the adhesive, ensuring uniform coating. The introduction of nano-titanium dioxide not only enhances the UV stability of the sealing layer but also endows it with self-cleaning properties. Through the synergistic formulation of its components, this sealant system achieves zero VOC emissions while maintaining excellent sealing performance. Its viscosity characteristics are designed to meet the requirements of electrostatic spin coating processes while ensuring the flexibility and durability of the cured sealing layer, perfectly adapting to the needs of high-speed continuous production.

[0016] As a preferred technical solution of the present invention, in the electrostatic spin coating process, the spray gun voltage is controlled at +15kV to +25kV, the substrate grounding voltage is -10kV to -20kV, the coating speed is 40-60mm / s, the coating thickness is 70-90μm, and the curing process adopts UV-hot air synergistic treatment, with UV intensity of 50-100mW / cm² and hot air temperature of 80-100℃.

[0017] The above technical solution utilizes a high-voltage electrostatic field to atomize and charge the sealant, enabling directional deposition of the sealant on the bottle cap surface under the drive of the electric field. It innovatively employs a reverse grounding voltage configuration on the substrate to enhance coating adhesion. The UV-hot air synergistic curing mechanism significantly shortens curing time through the combined effects of photo-initiated polymerization and thermo-induced crosslinking. This process overcomes the limitations of traditional coating technologies, such as low efficiency and poor uniformity, achieving complete sealing layer coverage with micron-level thickness control precision, while avoiding bottle cap deformation caused by high-temperature baking.

[0018] As a preferred embodiment of the present invention, the integrated production line comprises: Raw material processing module: equipped with a vacuum dryer, a loss-in-weight feeder, and a metal detection device; Injection molding module: adopts an eight-station rotary table structure, clamping force of 300-400 tons, and is equipped with an in-mold pressure sensor array; Coating and curing module: integrates a six-axis robotic arm, a high-voltage electrostatic generator, and a dual-band UV-LED curing unit; Sorting and Packaging Module: Equipped with a machine vision inspection system and a pneumatic sorting mechanism.

[0019] Using the above technical solution, this production line achieves precise drying and impurity removal of bio-based materials through a raw material processing module; a multi-station injection molding module with a rotary layout enables continuous flow of the molding process, and in-mold pressure sensing technology ensures stable molding quality; a coating and curing module integrates a robotic arm and an electrostatic generator to achieve precise positioning and efficient execution of the sealing process; and a sorting and packaging module combines machine vision and pneumatic control to complete product quality grading. All modules are seamlessly connected through an intelligent control system, forming a complete closed-loop production process. This completely changes the traditional production model of multiple separate processes and extensive manual intervention, achieving fully automated production from raw materials to finished products.

[0020] As a preferred technical solution of the present invention, the machine vision inspection system includes a 5MP high-speed industrial camera, a laser displacement sensor and a spectral analyzer. The inspection items include wall thickness uniformity, sealing layer integrity and microbial indicators, and the inspection frequency is ≥200 pieces / minute.

[0021] Employing the aforementioned technical solution, this testing system integrates high-resolution visual imaging, laser ranging, and spectral analysis technologies to achieve comprehensive testing of bottle cap dimensions, sealing layer integrity, and hygiene indicators: wall thickness uniformity testing ensures consistent product mechanical properties; sealing layer integrity analysis prevents microporous leakage defects; and microbial indicator monitoring guarantees hygiene and safety. The high-speed testing frequency is perfectly matched to the production line cycle time, forming a real-time quality monitoring network. Compared to traditional manual sampling methods, testing efficiency and accuracy are improved by orders of magnitude.

[0022] As a preferred technical solution of the present invention, it further includes a dynamic parameter control system, which comprises: Constitutive model of melt flow: A non-Newtonian fluid dynamics model is established based on the Cross-WLF equation; Adaptive injection control unit: Employs a PID-NN hybrid algorithm to adjust injection speed and holding pressure in real time; Heat transfer coefficient control module: dynamically adjusts cooling water flow rate through Reynolds number-Nusserl number correlation.

[0023] By adopting the above technical solution, this system accurately predicts the rheological behavior of materials by establishing a melt flow constitutive model and uses a hybrid intelligent algorithm to achieve real-time optimization and adjustment of injection parameters. It innovatively introduces classical heat transfer correlations into cooling control, dynamically adjusting the cooling intensity through the Reynolds number-Nusser number relationship. This control system overcomes the limitations of traditional equipment operating with fixed parameters, possessing the ability to adaptively adjust process parameters, effectively compensating for interference factors such as material fluctuations and environmental changes, and significantly improving production stability and product consistency.

[0024] As a preferred technical solution of the present invention, the quality traceability system uses blockchain technology to achieve data storage and includes: Laser marking unit: Forms traceability codes with a depth of 0.08-0.15mm on the product surface; Distributed storage nodes: record raw material batches, process parameters, and test results in real time; Quality early warning module: Set automatic alarm thresholds for temperature deviation ±3℃, pressure fluctuation ±5%, and dimensional deviation ±0.1mm.

[0025] By adopting the above technical solution, this system achieves unique product identification through laser marking, ensures the immutability of production data through distributed storage technology, and innovatively links process parameters, test results, and raw material batch information in a chain. The quality early warning module sets up multi-dimensional threshold monitoring to achieve early detection and rapid location of anomalies. This traceability system breaks through the limitations of traditional paper records or isolated databases, constructing a transparent and reliable quality information chain, which not only meets strict quality supervision requirements but also provides data support for production process optimization.

[0026] Compared with existing technologies, the beneficial effects of the iron-plastic composite crown-shaped bottle cap gradient molding process and intelligent production system of this invention are: Through innovative iron-plastic composite structure (using tinplate as a skeleton combined with microporous foamed plastic to achieve a balance between compressive strength and weight reduction), zirconium phosphate nanocrystal whisker interface strengthening technology (building a mechanical interlocking structure between metal and plastic to prevent delamination due to hot and cold cycles), asymmetric labyrinth sealing rib design (a trapezoidal cross-section with a narrow top and wide bottom, combined with 15° spiral radial secondary ribs to compensate for bottle mouth size errors), and an intelligent gradient molding production system (integrating continuous metal pretreatment, dual-material co-injection, in-mold shaping, and blockchain quality traceability modules), a comprehensive breakthrough has been achieved in bottle caps in terms of compressive strength, sealing reliability, material weight reduction, production efficiency, and quality stability. This has not only solved the industry problems of poor sealing elasticity of traditional metal caps and insufficient compressive strength of all-plastic caps, but also overcome the technical bottlenecks of easy delamination of the metal-plastic composite interface and weak adaptability of the sealing structure to bottle mouth tolerances. At the same time, the intelligent production system has improved process controllability and product consistency, promoting the upgrading of bottle cap manufacturing towards green, low-carbon, precise, reliable, efficient, and flexible directions. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the metal skeleton pretreatment and interface strengthening process of the present invention; Figure 2 This is a schematic diagram of the molding process of the present invention; Figure 3 This is a schematic diagram of the continuous production system architecture of the present invention; Figure 4 This is a schematic diagram of the gradient cooling system of the present invention; Figure 5 This is a schematic diagram of the data flow of the quality traceability system of the present invention; Figure 6 This is a schematic diagram of the gradient injection molding and sealing structure forming process of the present invention. Detailed Implementation

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] This embodiment addresses the delamination problem at the metal / plastic interface by optimizing the zirconium phosphate nanocrystal flocking process and plasma activation parameters, thereby increasing the interface peel strength to 40 N / cm (a 14% improvement compared to Embodiment 1).

[0033] S1, Preparation of nanofiber composite reinforcement layer: a. Optimized flocking solution formula by weight percentage; Zirconium phosphate nanocrystals: 18%, length 10-12μm, aspect ratio 1:22; epoxy-silane hybrid resin: 55%, curing temperature reduced to 160℃; carbon nanotube dispersion: 5%, to enhance conductivity, particle size 20nm; isopropanol 22%. The preparation process involves first ultrasonically dispersing carbon nanotubes at 40 kHz / 350 W for 30 min, and then mixing them with whiskers and resin at 40 °C and 200 rpm at a low speed.

[0034] b. High-voltage electrostatic flocking parameters: Electric field strength 18kV / cm, +25kV spray gun, -15kV substrate, flocking density 450 strands / mm², curing conditions 160℃ / 75s.

[0035] S2, gradient injection molding and interface activation a. Plasma activation process; Gas type: argon / oxygen mixture ratio 4:1; power density: 120W / cm²; processing time: 8 seconds; forming mechanically interlocked micropores with a depth of 0.5μm. b. Dynamic control of three-layer injection molding parameters:

[0036] Example 2

[0037] Continuous injection molding of material-based composite materials includes the following steps: S1. Raw material pretreatment: a. Material proportions (parts by weight): Bio-based PLA particles: 60 parts (particle size 2-3 mm, melt index 8 g / 10 min); Maleic anhydride-grafted PP: 30 parts (grafting rate 1.8%). Sodium-modified attapulgite: 8 parts (interlayer spacing 2.8 nm, modified with octadecyltrimethylammonium bromide); Tea tree oil microcapsules: 1.5 parts (chitosan-gelatin coating, particle size 20-50μm).

[0038] b. Operation: Put PLA and grafted PP into a high-speed mixer (300 rpm, 25°C) and premix for 10 minutes; Add sodium-modified attapulgite in three batches, with a 2-minute interval between each batch; Finally, add the microcapsules and mix at low speed (100 rpm) for 5 minutes.

[0039] S2, Melt extrusion and microcellular foaming: a. Twin-screw extruder equipment parameters (L / D=40:1): Feeding section 175℃; Compression section 195℃; Homogenization section 185℃; Supercritical CO2 injection pressure: 28 MPa (flow rate 1.2 L / min).

[0040] b. Operation: Start the extruder and set the feeding rate to 15 kg / h. CO2 is injected into the middle of the compression section, and the swelling ratio is controlled at 3.5:1; A shaping sleeve (Φ28.5mm±0.05mm) is installed at the mold exit.

[0041] S3, Cooling parameters for gradient cooling design: Level 1 air cooling: wind speed 8m / s, 20℃, 30 seconds; Two-stage water cooling: water temperature 15℃, immersion for 15 seconds; Three-level infrared balance: wavelength 3-5μm, 50W / cm², 10 seconds.

[0042] S4: Online detection and sorting: a. Test items: Density determination (Archimedes method): Target value 0.35±0.02 g / cm³; Aperture scanning (micro-CT): 50-80μm accounts for ≥95%; Warpage measurement (laser displacement sensor): ≤0.08mm / m.

[0043] b. Sorting logic: Qualified products are transported to the coating station; Non-conforming products are automatically crushed and reused (crushed particle size ≤ 3mm).

[0044] Example 3

[0045] The continuous coating process for environmentally friendly sealants and the automated coating and rapid curing of solvent-free sealants are described in the following steps: S1. Sealant formulation (by weight percentage):

[0046] The mixing process includes premixing plasticizer and APG at 50°C (magnetic stirring at 500 rpm). Slowly add the resin and stir for 1 hour (viscosity 2500±200mPa·s). Nano-TiO2 was ultrasonically dispersed (40kHz / 300W) for 20 minutes.

[0047] S2, Electrostatic Spin Coating: a. Equipment parameters: Six-axis robotic arm spin coater (repeatability ±0.01mm); Spray gun voltage: +20kV, substrate grounding -15kV; Coating speed: 50mm / s, distance: 30mm.

[0048] b. Operation: Heat the sealant to 45℃ (viscosity 1800 mPa·s); The coating time for each bottle cap is ≤3 seconds; Coating thickness 80±5μm (online laser thickness gauge).

[0049] S3, UV and hot air dual curing parameters: UV pre-curing: wavelength 365nm, intensity 80mW / cm², time 5 seconds; Hot air curing: Circulate hot air at 90℃ for 20 seconds; Cooling section: 10℃ cold air rapidly cools to room temperature.

[0050] S4. Test method for sealing performance: Negative pressure test: Hold at 0.08 MPa for 1 minute, leakage rate ≤0.5%; Torque test: Opening torque 2.0-2.8 N·m (digital torque meter).

[0051] Example 4

[0052] The integrated continuous production system for crown-shaped bottle caps, along with fully automated production and quality traceability, is implemented through the following steps: S1, Raw Material Supply System: a. Equipment composition: Vacuum feeder (processing capacity 200kg / h, accuracy ±0.5%). Loss-in-weight feeder (PLA / PP compartment control); Metal detector (sensitivity Φ0.3mm Fe ball).

[0053] b. Control logic: The moisture content of the raw materials is ≤0.02% (using an online infrared moisture meter). 100% foreign object removal rate (pneumatic nozzle spray); S2, Injection Molding-Coating Integrated Line: a. Production line parameters: Eight-station rotary table design (cycle time 8 seconds / mold); Clamping force 350 tons, injection volume 120g±0.5g; The coating is cured at 90°C for 25 seconds.

[0054] b. Collaborative operations: Workstations 1-2: Substrate loading and positioning; Stations 3-5: Injection molding of three-layer composite materials; Workstations 6-7: Double-sided sealant application; Workstation 8: Automatic unloading of finished products.

[0055] S3, Quality Traceability System: a. Data collection: Laser marking: Batch number + timestamp + machine number (depth 0.1mm); Blockchain-based evidence storage: Production parameters are uploaded to the blockchain in real time (once per minute).

[0056] b. Automatic alarm thresholds for anomaly handling: Temperature deviation > ±3℃; Pressure fluctuation > ±5%; Fault shutdown response time < 2 seconds.

[0057] Example 5

[0058] The multi-physics field coupling optimization and dynamic parameter control system for the crown-shaped bottle cap forming process includes the following implementation steps: 1. Multiphysics coupling modeling and process optimization This embodiment addresses the thermo-fluid-structure interaction effect during the injection molding stage of crown-shaped bottle caps by establishing an adaptive control model based on non-Newtonian fluid dynamics. Through real-time feedback of melt pressure and temperature fields, the injection molding parameters are dynamically corrected to solve the warping problem caused by uneven material shrinkage in traditional processes.

[0059] a. Constitutive equations of melt flow The non-Newtonian properties of PLA / PP composites are described using a modified Cross-WLF model:

[0060] in:

[0061] Parameter calibration value: D1 = 2.5 × 10 11 Pa / cdotps, A1=35.2, A2=51.6K, n=0.28, τ * =1.8×10 4 Pa.

[0062] b. Mold Cavity Pressure Field Prediction Algorithm A three-dimensional transient pressure field model is constructed based on the finite volume method, and an improved SIMPLEC algorithm is used for iterative solution.

[0063] In the formula, the source term S includes the microporous foaming effect:

[0064] Among them, ∅ g The gas volume fraction is updated using real-time pressure sensor data (sampling frequency 500Hz).

[0065] 2. Adaptive process parameter control system a. Optimize dynamic injection speed and establish a PID-NN hybrid control model based on mold cavity pressure feedback:

[0066] In the formula, the neural network correction term ∅ NN A three-layer BP network structure is adopted: Input layer: Average pressure P in the mold cavity aug Temperature difference ∆T=T melt -T mold ; Hidden layer: 10 nodes with activation function tanh; Output layer: velocity correction ∆u∈[-5%, +5%]; The training dataset contains 8,000 sets of historical process data. The Levenberg-Marquardt algorithm is used to optimize the weight matrix, and the convergence error is <0.5%.

[0067] b. Dynamic matching of the cooling system: Adaptive control equation for heat transfer coefficient.

[0068] In the formula, the Nusselt number Nu is calculated in real time based on the Reynolds number Re:

[0069] Dynamic heat transfer control is achieved by adjusting the cooling water flow rate. The flow rate adjustment function is:

[0070] Where A = 2.35m 2 The heat exchange area of ​​the mold temperature controller has a response time of <0.5s.

[0071] 3. Defect prediction and self-healing mechanism a. The warping deformation prediction model is established based on the deformation prediction equation of orthogonal anisotropy theory:

[0072] The improved Taguchi method was used to optimize the combination of process parameters: Control factors: melt temperature (A), holding pressure (B), cooling time (C); Horizontal setting: 3-level orthogonal array L9(3^4); Signal-to-noise ratio calculation:

[0073] Experimental data show that the optimal combination is A2B3C1, which can reduce warpage.

[0074] b. The development of the online defect compensation system is based on a real-time correction module using machine vision: Image acquisition: 5MP high-speed industrial camera (200fps). Feature extraction: Sobel operator edge detection combined with Hough transform roundness analysis; Defect classification: SVM classifier (RBF kernel, C=1.2, γ=0.05).

[0075] 4. System Integration and Verification a. Hardware configuration:

[0076] b. Production validation data and comparison of key performance indicators from continuous production testing of 100,000 bottle caps:

[0077] c. Environmental benefit analysis using material utilization optimization algorithms:

[0078] Compared with traditional processes, it improves efficiency by 9.5 percentage points and can reduce PLA raw material waste by about 23 tons per year. Among these improvements, the dynamic adjustment error of injection speed is less than ±0.8%, the energy consumption of the cooling system is reduced by 31.2%, the product size qualification rate is increased to 99.2%, and the raw material utilization rate breaks through the industry bottleneck of 92%. The relevant algorithms have been encapsulated as DLL components and integrated into the MES system, supporting the OPCUA protocol to achieve bidirectional data interaction with the ERP system.

[0079] Example 6

[0080] The iron-plastic composite crown-shaped bottle cap gradient molding process and intelligent production system provided by this invention, through material innovation and process integration, constructs a complete green manufacturing technology system. This embodiment comprehensively describes its overall process flow and system architecture: In terms of preparation process, bio-based composite materials are used as the main raw materials, and the compatibility of materials is improved through precise proportioning and surface modification technology; After pretreatment, the raw materials enter a multi-stage blending extrusion system, and lightweight molding is achieved by combining supercritical fluid microporous foaming technology. Dynamic pressure control and gradient cooling strategies are used in the injection molding stage to effectively control product shrinkage and deformation. The molded bottle cap substrate is treated with a solvent-free sealant electrostatic spin coating process, and then cured by UV-hot air to form a sealing layer, achieving zero emissions of volatile organic compounds throughout the entire process.

[0081] At the production system level, a modular continuous production line was built, integrating intelligent material feeding, multi-station injection molding, automatic coating, online detection and sorting units; The system adopts a distributed control system to achieve coordinated optimization of injection molding parameters and coating process, and monitors key quality indicators in real time through machine vision and sensor network. The production line is equipped with a blockchain traceability module to enable full-process tracking of raw material batches, process parameters, and quality data.

[0082] This system innovatively combines biodegradable material technology, microporous foaming weight reduction process with intelligent manufacturing equipment. Through a closed-loop control system, it achieves dynamic compensation of process parameters, ensuring the stability of product dimensional accuracy and sealing performance.

[0083] Example 7 This embodiment integrates deep learning algorithms and machine vision to achieve real-time defect prediction and process self-correction, reducing the defect rate to 0.5% (a 37.5% improvement compared to Embodiment 3).

[0084] S1. Upgrade of Intelligent Detection System: a. Enhanced machine vision module; camera resolution: 8MP (originally 5MP); frame rate: 250fps The algorithm architecture is a YOLOv5 defect detection model, with a training dataset of 100,000 images. New detection items have been added, including the uniformity of interface whisker distribution and the tolerance of the spiral angle of the sealing ribs (±0.5°).

[0085] b. Real-time feedback control and dynamic adjustment of injection parameters: Based on visual inspection results, the injection pressure (±3MPa) is adjusted in real time through the PID-NN algorithm. When the self-healing mechanism detects uneven micropores, it automatically triggers in-mold hot pressing and shaping at a pressure of 90 tons for 10 seconds. S2, Deepening Blockchain Traceability: The data chain extension adds new record items: AI diagnostic results and self-correction instruction logs, with a storage frequency of once per second (originally once per minute). The early warning module upgrades its thresholds and dynamically adjusts them, learning from historical data to optimize alarm thresholds, such as adaptive dimensional deviation of ±0.08mm.

[0086] Root cause analysis: Automatically associates abnormal process parameters with defect types, such as temperature deviation → deformation of sealing ribs.

[0087] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0088] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is limited by the appended claims and their equivalents.

Claims

1. A gradient molding process and intelligent production system for iron-plastic composite crown-shaped bottle caps, characterized in that, include: Substrate pretreatment process: tinplate strip is laser-cut and formed, and a zirconium phosphate nanocrystal reinforcement layer is flocked on the surface; Gradient composite injection molding process: Microporous foamed plastic layers are injected on both sides of a metal skeleton, and an antibacterial sealing material is composited in the middle layer; Interface strengthening process: forming a mechanical interlocking structure at the metal / plastic interface through plasma activation; Asymmetric sealing structure molding process: A trapezoidal labyrinth sealing rib with a narrow top and a wide bottom is injected into the top, and the secondary ribs are arranged in a 15° spiral radial pattern. Intelligent production system: includes metal pretreatment module, dual-material co-injection module, online heat treatment module and blockchain traceability system; The preparation process of bio-based composite materials involves blending polylactic acid matrix materials with compatible modified polymers, composite nano-inorganic fillers, and antibacterial functional components. The supercritical fluid microporous foaming molding process achieves lightweight closed-cell structure molding by precisely controlling the supercritical fluid injection parameters. The gradient cooling and shaping process employs a three-stage separately controlled cooling system to achieve stress balance control of the product. The solvent-free sealant continuous coating process achieves uniform coating and rapid curing of the sealing layer through electrostatic spin coating. The integrated production line architecture is a continuous production system that includes an intelligent material feeding module, a multi-station injection molding module, an online testing module, and a quality traceability system.

2. The gradient molding process for an iron-plastic composite crown-shaped bottle cap according to claim 1, characterized in that: Tinplate strip thickness 0.18-0.25mm, tensile strength ≥350MPa; Zirconium phosphate nanocrystals have a length of 5-15 μm, a diameter-to-length ratio of 1:20, and a flocking density of 200-400 nanocrystals / mm². The flocking process uses a high-voltage electrostatic field combined with a thermosetting adhesive.

3. The gradient molding process for an iron-plastic composite crown-shaped bottle cap according to claim 1, characterized in that: The gradient composite injection molding comprises a three-layer structure: S1, Metal bonding layer: Maleic anhydride grafted polypropylene (40-60 parts) + glass microspheres (10-15 parts). S2, Microporous foaming layer: Supercritical N2 foamed polyester (foaming ratio 3.5-4.2 times, pore size 50-80μm); S3, Sealing functional layer: Fluororubber / nano silica composite (Shore hardness 65-75A).

4. The gradient molding process for an iron-plastic composite crown-shaped bottle cap according to claim 1, characterized in that: The main reinforcement bars are 1.2-1.8mm high, with a trapezoidal cross-section of 0.3mm top width and 0.8mm bottom width. The secondary reinforcement bars are radially distributed with a 15° spiral angle, and the surface Ra of the reinforcement bars is ≤0.8μm; The interference fit for the annular groove at the bottle mouth is designed to be 0.15-0.25mm.

5. The gradient molding process for an iron-plastic composite crown-shaped bottle cap according to claim 1, characterized in that: Continuous feeding unit for metal strip: unwinding speed 20-30m / min, tension control ±1.5N; Rotary dual-station mold: the first station injects the bonding layer (temperature 190-210℃), and the second station injects the foaming layer (temperature 165-185℃). In-mold hot pressing shaping mechanism: pressure 80-100 tons, holding time 8-12 seconds.

6. The gradient intelligent production system for iron-plastic composite crown-shaped bottle caps according to claim 1, characterized in that: The bio-based composite material comprises, by weight, 60-80 parts of polylactic acid, 20-40 parts of maleic anhydride-grafted polyolefin, 5-10 parts of modified nanoclay, and 0.5-2 parts of plant extract microcapsules, wherein the melt index of the polylactic acid matrix is ​​5-10 g / 10 min, and the nanoclay interlayer spacing is ≥2.5 nm and has undergone organic intercalation treatment.

7. The gradient intelligent production system for iron-plastic composite crown-shaped bottle caps according to claim 6, characterized in that: In the supercritical fluid microporous foaming molding process, the supercritical CO2 injection pressure is controlled at 25-35MPa, the melt temperature is adjusted in three gradients within the range of 170-200℃, the swelling ratio is maintained at 3.0-4.0:1, and a constant temperature shaping sleeve is set at the mold outlet.

8. The gradient intelligent production system for iron-plastic composite crown-shaped bottle caps according to claim 2, characterized in that: The gradient cooling and shaping process specifically includes: a. Level 1 air-cooling stage: wind speed 5-10m / s, temperature 15-25℃, duration 20-40 seconds; b. Secondary liquid cooling stage: Cooling medium temperature 10-20℃, immersion time 10-20 seconds; c. Third-level infrared balancing stage: Mid-wave infrared radiation is used, with a power density of 30-60W / cm² and a processing time of 5-15 seconds.

9. The gradient intelligent production system for iron-plastic composite crown-shaped bottle caps according to claim 6, characterized in that: The solvent-free sealant comprises 40-50% polyvinyl chloride paste resin, 30-40% bio-based plasticizer, 2-5% surfactant, and 1-3% nano titanium dioxide, wherein the plasticizer is a citrate ester compound, and the sealant viscosity is 2000-3000 mPa·s.

10. The gradient intelligent production system for iron-plastic composite crown-shaped bottle caps according to claim 6, characterized in that: In the electrostatic spin coating process, the spray gun voltage is controlled between +15kV and +25kV, the substrate grounding voltage is between -10kV and -20kV, the coating speed is 40-60mm / s, the coating thickness is 70-90μm, and the curing process adopts UV-hot air synergistic treatment with UV intensity of 50-100mW / cm² and hot air temperature of 80-100℃. The integrated production line includes: Raw material processing module: equipped with a vacuum dryer, a loss-in-weight feeder, and a metal detection device; Injection molding module: adopts an eight-station rotary table structure, clamping force of 300-400 tons, and is equipped with an in-mold pressure sensor array; Coating and curing module: integrates a six-axis robotic arm, a high-voltage electrostatic generator, and a dual-band UV-LED curing unit; Sorting and packaging module: Equipped with a machine vision inspection system and a pneumatic sorting mechanism; The machine vision inspection system includes a 5MP high-speed industrial camera, a laser displacement sensor and a spectral analyzer. The inspection items include wall thickness uniformity, sealing layer integrity and microbial indicators. The inspection frequency is ≥200 pieces / minute. It also includes a dynamic parameter control system, which comprises: Constitutive model of melt flow: A non-Newtonian fluid dynamics model is established based on the Cross-WLF equation; Adaptive injection control unit: Employs a PID-NN hybrid algorithm to adjust injection speed and holding pressure in real time; Heat transfer coefficient control module: dynamically adjusts cooling water flow rate through Reynolds number-Nusser number correlation; The quality traceability system uses blockchain technology for data storage and includes: Laser marking unit: Forms traceability codes with a depth of 0.08-0.15mm on the product surface; Distributed storage nodes: record raw material batches, process parameters, and test results in real time; Quality early warning module: Set automatic alarm thresholds for temperature deviation ±3℃, pressure fluctuation ±5%, and dimensional deviation ±0.1mm.

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