ABS ultrathin wall injection molding process

Abstract

The invention belongs to the technical field of ABS (Acrylonitrile Butadiene Styrene) molding, and discloses an ABS ultrathin wall injection molding process which comprises the following steps: S1, material modification; s2, configuring equipment and a mold; s3, injection molding is executed; s4, demolding and process control; s5, post-processing and detecting; the material modification comprises the steps of preparing a high-flowability ABS base material and carrying out drying pretreatment. According to the method, ordered arrangement of molecular chains is kept in the high-speed filling process, weld line weakening and internal stress concentration are effectively restrained, and the surface thickness uniformity of the ultrathin wall meets the optical-grade requirement. Dynamic pressure closed-loop control is combined with a vacuum auxiliary exhaust mechanism, real-time matching of the melt front temperature and the cavity pressure is achieved, the defect of short injection or surface flow marks caused by air trapping in a traditional process is eliminated, and the distribution error of a mold thermal field is reduced to the micron order through cooperation of partition mold temperature control and a quick response heating element; the dimensional stability and assembly precision of the complex thin-wall structure are guaranteed, and meanwhile energy consumption of the cooling period is reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field of ABS molding, and specifically relates to an ABS ultra-thin wall injection molding process. Background Art

[0002] The ABS ultra-thin wall injection molding process is a high-precision injection technology suitable for manufacturing ultra-thin wall plastic products. It is often used in the production of thin-walled, lightweight, and high-strength products, such as mobile phone cases, automotive parts, and household appliance casings. This process precisely controls temperature, pressure, and injection speed during injection molding, enabling the ABS (acrylonitrile-butadiene-styrene copolymer) material to flow uniformly and fill every corner of the mold, ensuring that the wall thickness of the finished product is uniform and the strength meets the usage requirements. To achieve ultra-thin wall molding, the ABS ultra-thin wall injection process usually requires the use of advanced mold design and cooling technologies to ensure uniform temperature changes during injection molding, preventing the plastic from deforming due to rapid cooling after being injected into the mold. The core challenge of this technology lies in precisely controlling the injection speed and pressure to prevent defects such as warping and bubbles in thin-walled products during injection. Compared with traditional injection molding, the ABS ultra-thin wall injection process has higher production efficiency and lower material waste, and is suitable for large-scale production. Due to the good impact resistance and chemical stability of its materials, the products produced using this process not only have excellent mechanical properties but also high surface finish, meeting the design requirements of modern industry and consumer products.

[0003] Traditional ABS materials face problems such as short flow paths and fast cooling speeds in ultra-thin wall injection molding. The narrow cavity of the ultra-thin wall (usually <1.0 mm) significantly increases the melt flow resistance, requiring an injection pressure >100 MPa. However, the melt flow index (MFI) of conventional ABS is usually lower than 15 g / 10 min, making it difficult to meet the rapid filling requirements at high shear rates. At the same time, the melt is prone to decomposition due to shear heat during high-speed injection (>200 mm / s), resulting in defects such as air marks or charring. Traditional processes have not fully optimized material modification (such as not adding flow enhancers), resulting in the formation of weld lines and internal stress concentration during high-speed filling of the material. Moreover, the holding pressure parameters (such as time and pressure) have not been redesigned for thin-walled structures, further exacerbating the risk of uneven shrinkage and warping deformation.

[0004] Traditional mold design is difficult to meet the high-precision requirements of ultra-thin-wall injection molding. For example, the depth of the exhaust system is usually not reduced by 25% to adapt to ultra-thin cavities, resulting in air entrapment at the flow front, causing short shots or surface flow marks. The gate design does not give priority to using hot runners or fan gates, resulting in local pressure loss and filling imbalance. At the same time, the insufficient precision of mold temperature control (the temperature difference is usually >3°C) directly affects dimensional stability - a mold temperature fluctuation of 2°C can cause a product size deviation of up to 0.02mm, and the traditional process lacks zone temperature control and rapid-response heating elements, making it difficult to achieve the stability requirement of ±1°C. In addition, the demolding system is not adjusted according to the thin-wall characteristics (such as insufficient number or small size of ejector pins), which is likely to cause defects such as ejection through or sticking to the mold. Summary of the Invention

[0005] The purpose of the present invention is to provide an ABS ultra-thin-wall injection molding process to solve the problems raised in the above-mentioned background technology.

[0006] To achieve the above purpose, the present invention provides the following technical solution: an ABS ultra-thin-wall injection molding process, including the following steps:

[0007] S1: Material modification;

[0008] S2: Equipment and mold configuration;

[0009] S3: Injection molding execution;

[0010] S4: Demolding and process control;

[0011] S5: Post-treatment and inspection;

[0012] The material modification includes formulating a high-flow ABS substrate and drying pretreatment. The equipment and mold configuration include injection molding machine debugging and mold installation. The injection molding execution includes high-speed filling in the first stage, low-speed compensation in the second stage, and clamping force regulation. The demolding and process control include melt residence management and ejection control. The post-treatment and inspection include surface passivation and on-line quality inspection.

[0013] As a further technical solution of the present invention, formulating the high-flow ABS substrate includes using an electroplating-grade ABS resin with a melt flow index MFI≥35g / 10min as the substrate, mixing 5% of nano-silica with a particle size of 30 - 50nm treated with surface silane coupling, 0.3% of hindered phenol antioxidant, and 0.5% of polyethylene wax lubricant, and melting and blending using a twin-screw mixer at 220°C, controlling the shear rate at 800s -1To ensure that the deviation of the nanoparticle dispersion uniformity is ≤3%, the drying pretreatment includes putting the mixed resin into a twin-tower dehumidifying dryer, setting the temperature at 85±2°C, the drying time at 4 hours, the dew point temperature at -40°C, using an infrared moisture meter to detect the moisture content every 15 minutes until it is ≤0.05%, and the dried material must be transferred to the injection molding machine hopper within 30 minutes.

[0014] As a further technical solution of the present invention, the debugging of the injection molding machine includes installing a barrier screw with a length-diameter ratio of 20:1 and a compression ratio of 2.8:1, setting the barrel four-zone temperatures: the rear zone at 190-200°C, the middle zone at 210-220°C, the front zone at 230-240°C, and the nozzle at 235-245°C, the PID temperature control accuracy is ±1°C, and calibrating the screw speed to the range of 80-120 rpm.

[0015] As a further technical solution of the present invention, the mold installation includes assembling a hot runner system with a 0.8mm×0.3mm flat fan-shaped gate, the runner diameter is Φ3.5mm, the gate distance from the end of the cavity is ≤15mm, the depth of the main exhaust groove is 0.02mm, the depth of the auxiliary exhaust groove on the parting surface is 0.05mm, the width is 5mm, the spacing is 15mm, connecting a vacuum pump to maintain a negative pressure of -0.08MPa, setting the mold temperature in zones: the cavity at 65±1°C and the core at 63±1°C, arranging cooling water channels with a Φ8mm spacing of 15mm, injecting an ethylene glycol aqueous solution at 20L / min, and the temperature control accuracy is ±0.5°C.

[0016] As a further technical solution of the present invention, in the first stage of high-speed filling, start the dynamic pressure closed-loop control system, the injection pressure is 130-150MPa, the melt fills 90% of the cavity volume at a speed of 300mm / s, and monitor that the melt front temperature is ≥210°C. In the second stage of low-speed compensation, the injection speed is reduced to 150mm / s, the holding pressure is 30-40MPa, the holding time is 0.8-1.2 seconds, and the holding pressure curve is adjusted in real time through the cavity pressure sensor, with an error of ±0.5Mpa.

[0017] As a further technical solution of the present invention, the clamping force regulation includes an initial clamping force of 600t, dynamically compensating ±5% according to the data of the melt peak pressure sensor, and the hydraulic response time is ≤50ms.

[0018] As a further technical solution of the present invention, the melt residence management includes that the residence time of the melt in the barrel is ≤180 seconds, setting the screw back pressure at 8-10MPa to avoid thermal degradation. The ejection control includes triggering a two-stage ejection program, switching to a high speed of 5mm / s for demolding after contacting the product at a low speed of 0.5mm / s, and configuring a Φ2mm nitrided ejector pin density of ≥12 pieces / m 2 and the ejector rod stroke error is ≤0.02mm.

[0019] As a further technical solution of the present invention, the surface passivation includes subjecting electroplated products to hot air circulation treatment at 80°C for 2 hours with a humidity ≤ 30%; non-electroplated products are treated in a 500W plasma reaction chamber for 30 seconds with a plasma density ≥ 1×10 12 / cm 3 , and the in-line quality inspection includes real-time detection of the wall thickness tolerance of ±0.05mm by a laser scanner, dynamic fine-tuning of ±2°C by a mold temperature compensation system according to warpage data, and controlling the defect rates of air marks and weld lines to ≤ 0.5% and ≥ 90% of the substrate strength respectively. The MES system records the process stability report of the injection pressure slope and the mold temperature fluctuation ≤ ±0.3°C.

[0020] The beneficial effects of the present invention are as follows:

[0021] (1) Through the collaborative innovation of materials and processes, the present invention significantly improves the forming accuracy and functional reliability of ultra-thin-wall injection molded products. The combined effect of the high-flowability substrate and the nano-reinforcing phase endows the melt with excellent low-shear viscosity characteristics, maintains the orderly arrangement of molecular chains during the high-speed filling process, effectively inhibits the weakening of weld lines and the concentration of internal stress, and enables the wall thickness uniformity of the ultra-thin wall to meet the optical grade requirements. The dynamic pressure closed-loop control combined with the vacuum-assisted exhaust mechanism realizes the real-time matching of the melt front temperature and the cavity pressure, eliminates the short-shot or surface flow mark defects caused by air entrapment in the traditional process. The cooperation of the zone mold temperature control and the fast-response heating element reduces the error of the mold thermal field distribution to the micron level, ensures the dimensional stability and assembly accuracy of complex thin-wall structures, and reduces the energy consumption during the cooling cycle at the same time.

[0022] (2) Through the in-depth optimization of equipment and process parameters, the present invention constructs a closed-loop ultra-thin injection molding production with high precision and low defects. The synergistic effect of the hot runner flat gate design and the nitrided ejector pin system greatly reduces the shear heat accumulation and the risk of demolding damage in the gate area, making the surface finish of the product close to the mirror effect. The combined use of the two-stage ejection procedure and the plasma surface treatment enhances the anti-scratch and environmental aging resistance of thin-wall parts while improving the demolding efficiency. The in-line quality monitoring system dynamically compensates for process parameter deviations by real-time collecting melt flow data and mold temperature fluctuation information, making the performance consistency of batch products meet the industrial-level strict standards, and providing data support for the continuous optimization of the process, significantly reducing the scrap rate and the later repair cost. Brief Description of the Drawings

[0023] Figure 1 is a schematic diagram of the overall process of the present invention;

[0024] Figure 2 is a schematic diagram of the process of material modification of the present invention;

[0025] Figure 3 is a schematic diagram of the equipment and mold configuration of the present invention;

[0026] Figure 4 Schematic flow chart for injection molding implementation of the present invention;

[0027] Figure 5 Schematic flow chart for demolding and process control of the present invention;

[0028] Figure 6 Schematic flow chart for post-treatment and inspection of the present invention. Detailed implementation manners

[0029] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] As Figures 1 to 6 shown, in the embodiment of the present invention, an ABS ultra-thin wall injection molding process includes the following steps:

[0031] S1: Material modification;

[0032] S2: Equipment and mold configuration;

[0033] S3: Injection molding implementation;

[0034] S4: Demolding and process control;

[0035] S5: Post-treatment and inspection;

[0036] Material modification includes preparing a high-flow ABS substrate and drying pretreatment. Equipment and mold configuration includes injection molding machine debugging and mold installation. Injection molding implementation includes high-speed filling in the first stage, low-speed compensation in the second stage, and clamping force regulation. Demolding and process control includes melt residence management and ejection control. Post-treatment and inspection includes surface passivation and online quality inspection.

[0037] By significantly improving the filling integrity of the melt in the ultra-thin cavity through material flow modification, the decomposition defects caused by shear heat are eliminated, ensuring that the surface of the product is smooth and free of air marks. The mold system adopts precise temperature control and vacuum-assisted exhaust technology, effectively avoiding short shots and flow marks caused by the cooling and stagnation of the melt front, and simultaneously optimizing the weld line strength and dimensional stability. The dynamic clamping force compensation mechanism balances the injection pressure fluctuation in real time, suppressing the warping deformation of thin-walled products. The stepped ejection program combined with a nitrided ejector pin array realizes efficient demolding while maintaining the structural integrity. The surface passivation treatment strengthens the coating adhesion through the action of directional energy, and forms a closed-loop quality control in cooperation with the online laser detection system, finally achieving the large-scale stable production of high-precision ultra-thin wall products.

[0038] As Figure 2 shown, the preparation of the high-flow ABS substrate involves using an electroplating-grade ABS resin with a melt flow index MFI ≥ 35 g / 10 min as the substrate, mixing 5% of nano-silica with a particle size of 30 - 50 nm treated with surface silane coupling, 0.3% of a hindered phenol antioxidant, and 0.5% of a polyethylene wax lubricant, and performing melt blending at 220°C using a twin-screw mixer while controlling the shear rate at 800 s -1 to ensure that the deviation of the nano-particle dispersion uniformity is ≤ 3%. The drying pretreatment includes feeding the mixed resin into a twin-tower dehumidifying dryer, setting the temperature at 85 ± 2°C, the drying time at 4 hours, the dew point temperature at -40°C, using an infrared moisture meter to detect the moisture content every 15 minutes until it is ≤ 0.05%, and the dried material must be transferred to the injection molding machine hopper within 30 minutes.

[0039] By optimizing the material formula and pretreatment process, the flow performance and thermal stability of the ABS substrate are significantly improved, enabling the melt to achieve uniform filling during the ultra-thin molding process and avoiding the risk of thermal decomposition. The high-precision dispersion of nano-particles and the resin matrix enhances the cohesive strength of the material, and the synergistic effect of the antioxidant and lubricant effectively inhibits oxidation degradation and frictional loss during processing. The accurately controlled drying process completely eliminates the interference of residual moisture on the melt flow, prevents bubble and silver streak defects on the molding surface, and at the same time ensures the resin activity through time-effective material transfer, providing a stable melt quality basis for subsequent injection molding, and ultimately achieving efficient and low-loss molding of ultra-thin wall products.

[0040] As Figure 3 shown, the commissioning of the injection molding machine includes installing a barrier screw with a length-diameter ratio of 20:1 and a compression ratio of 2.8:1, setting the barrel four-zone temperatures: the rear zone at 190 - 200°C, the middle zone at 210 - 220°C, the front zone at 230 - 240°C, and the nozzle at 235 - 245°C, with a PID temperature control accuracy of ±1°C, calibrating the screw speed to the range of 80 - 120 rpm. The mold installation includes assembling a hot runner system with a 0.8 mm × 0.3 mm flat fan-shaped gate, a runner diameter of Φ3.5 mm, the gate distance from the cavity end ≤ 15 mm, the main exhaust groove depth of 0.02 mm, the auxiliary exhaust groove depth of 0.05 mm, width of 5 mm, and spacing of 15 mm on the parting surface, connecting a vacuum pump to maintain a negative pressure of -0.08 MPa, setting the mold temperature in zones: the cavity at 65 ± 1°C and the core at 63 ± 1°C, arranging cooling water channels with a diameter of Φ8 mm and a spacing of 15 mm, injecting an ethylene glycol aqueous solution at 20 L / min, with a temperature control accuracy of ±0.5°C.

[0041] Through customized injection molding equipment and mold systems, precise control of melt plasticization uniformity and flow path is achieved, ensuring complete filling of the ultra-thin wall structure without melt retention or shear overheating. The multi-stage temperature control system safeguards the thermal stability of the material during transportation, avoiding the risks of coking or degradation; the refined gate design and vacuum-assisted exhaust work together to eliminate trapped air at the flow end, significantly enhancing the surface finish of the product. The mold temperature zoning regulation combined with the efficient cooling medium circulation precisely balances the shrinkage differences in the thin-walled areas, suppressing warping deformation and maintaining dimensional consistency.

[0042] As Figure 4 shown, in the first stage of high-speed filling, the dynamic pressure closed-loop control system is activated, with an injection pressure of 130 - 150 MPa. The melt fills 90% of the cavity volume at a speed of 300 mm / s, and the melt front temperature is monitored to be ≥ 210°C. In the second stage of low-speed compensation, the injection speed is reduced to 150 mm / s, the holding pressure is 30 - 40 MPa, and the holding time is 0.8 - 1.2 seconds. The holding pressure curve is adjusted in real-time through the cavity pressure sensor feedback, with an error of ±0.5 Mpa. The clamping force regulation includes an initial clamping force of 600 t, dynamically compensated by ±5% according to the melt peak pressure sensor data, and the hydraulic response time ≤ 50 ms.

[0043] Through hierarchical filling and dynamic pressure collaborative control, it is ensured that the melt quickly and evenly covers the main body of the cavity, while avoiding the breakage of molecular chains caused by high-speed shear, and guaranteeing the complete molding of the thin-walled structure. The intelligent compensation system tracks the melt shrinkage trend in real-time, precisely compensates for volume changes, and eliminates local depressions and internal voids. The closed-loop clamping adjustment immediately counteracts the mold deformation caused by the melt impact, maintains the dimensional stability of the cavity, and prevents flash and burr defects. The precise matching of the pressure curve and the temperature field effectively suppresses the accumulation of residual stress, enabling the mechanical properties and surface quality of the product to meet the standards simultaneously, and ultimately achieving the high-efficiency and precision molding of the ultra-thin wall structure.

[0044] As Figure 5 shown, the melt residence management includes a melt residence time in the barrel ≤ 180 seconds, and a screw back pressure of 8 - 10 MPa is set to avoid thermal degradation. The ejection control includes triggering a two-stage ejection program, with a low speed of 0.5 mm / s to contact the product and then switching to a high speed of 5 mm / s for demolding. The configuration of Φ2 mm nitrided ejector pins has a density ≥ 12 pieces / m 2 , and the ejector rod stroke error ≤ 0.02 mm.

[0045] By precisely controlling the melt residence time and back pressure parameters, the thermal stability of the material is effectively maintained, avoiding molecular chain breakage or yellowing phenomena, and ensuring the melt density and color uniformity. The two-stage ejection mechanism achieves flexible contact and rapid separation during the demolding process. The high-density arrangement and low-friction characteristics of the nitrided ejector pins significantly reduce the risk of piercing through, eliminating surface scratches or deformations on the product. The strict constraint of the stroke error guarantees the synchronization of the ejection action and the mold surface, preventing microcracks caused by local stress concentration, and ultimately achieving damage-free demolding and structural integrity of the ultra-thin wall products.

[0046] As Figure 6 shown, surface passivation includes treating electroplated products with hot air circulation at 80 °C for 2 hours, with humidity ≤ 30%; non-electroplated products are treated in a 500W plasma reaction chamber for 30 seconds, with plasma density ≥ 1×10 12 / cm 3 , and in-line quality inspection includes real-time detection of wall thickness tolerance of ±0.05 mm by a laser scanner, dynamic fine-tuning of ±2 °C by the mold temperature compensation system according to warpage data, and defect rates of air marks and weld lines are controlled at ≤ 0.5% and ≥ 90% of the substrate strength respectively, and the MES system records the process stability report of injection pressure slope and mold temperature fluctuation ≤ ±0.3 °C.

[0047] Through the directional surface treatment technology, the bonding strength between the electroplated layer and the substrate and the surface energy of non-electroplated products are significantly improved, eliminating coating peeling or adhesion failure caused by micro-defects. The synergistic effect of laser scanning and dynamic mold temperature compensation corrects product deformation in real time and locks the key dimensional accuracy, ensuring the geometric stability of the ultra-thin wall structure. The full-process defect monitoring system accurately locates the weak areas of air marks and welds, and synchronously optimizes process parameters to maintain mechanical property consistency.

[0048] Through the collaborative innovation of materials and processes, the molding accuracy and functional reliability of ultra-thin wall injection molded products have been significantly improved. The composite effect of high-flowability substrate and nano-reinforcing phase endows the melt with excellent low-shear viscosity characteristics, maintaining the ordered arrangement of molecular chains during the high-speed filling process, effectively suppressing the weakening of weld lines and the concentration of internal stress, and making the wall thickness uniformity of the ultra-thin wall reach the optical grade requirements. The dynamic pressure closed-loop control combined with the vacuum-assisted exhaust mechanism realizes the real-time matching of the melt front temperature and the cavity pressure, eliminating the short-shot or surface flow mark defects caused by air entrapment in traditional processes. The cooperation of zone mold temperature control and fast-response heating elements reduces the mold thermal field distribution error to the micron level, ensuring the dimensional stability and assembly accuracy of complex thin-wall structures, while reducing the energy consumption of the cooling cycle.

[0049] Through the in-depth optimization of equipment and process parameters, a closed-loop ultra-thin injection molding production with high precision and low defects is constructed. The synergistic effect of the hot runner flat gate design and the nitrided ejector pin system significantly reduces the shear heat accumulation in the gate area and the risk of demolding damage, making the surface finish of the product close to the mirror effect. The combined use of the two-stage ejection procedure and plasma surface treatment enhances the scratch resistance and environmental aging resistance of thin-walled parts while improving the demolding efficiency. The on-line quality monitoring system dynamically compensates for process parameter deviations by collecting melt flow data and mold temperature fluctuation information in real time, achieving industrial-grade strict standards for the performance consistency of batch products and providing data support for continuous process optimization, significantly reducing the scrap rate and post-repair costs.

[0050] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ABS ultra-thin wall injection molding process, characterized in that: It includes the following steps: S1: Material modification; S2: Equipment and mold configuration; S3: Injection molding execution; S4: Demolding and process control; S5: Post-treatment and inspection; The material modification includes preparing a high-flow ABS substrate and drying pretreatment. The equipment and mold configuration includes injection molding machine debugging and mold installation. The injection molding execution includes high-speed filling in the first stage, low-speed compensation in the second stage, and clamping force regulation. The demolding and process control includes melt residence management and ejection control. The post-treatment and inspection includes surface passivation and online quality inspection.

2. The ABS ultra-thin wall injection molding process according to claim 1, characterized in that: The formulated high-flow ABS substrate includes using an electroplating-grade ABS resin with a melt flow index MFI ≥ 35 g / 10 min as the substrate, mixing 5% of nano-silica with a particle size of 30 - 50 nm treated with surface silane coupling, 0.3% of a hindered phenol antioxidant, and 0.5% of a polyethylene wax lubricant, and performing melt blending at 220 °C using a twin-screw mixer, controlling the shear rate at 800 s -1 to ensure that the deviation of the dispersion uniformity of the nanoparticles is ≤ 3%. The drying pretreatment includes feeding the mixed resin into a twin-tower dehumidifying dryer, setting the temperature at 85 ± 2 °C, the drying time at 4 hours, the dew point temperature at -40 °C, using an infrared moisture analyzer to detect the moisture content every 15 minutes until it is ≤ 0.05%, and the dried material must be transferred to the hopper of the injection molding machine within 30 minutes.

3. A kind of ABS ultra-thin wall injection molding process according to claim 1, characterized in that: The injection molding machine debugging includes installing a barrier screw with a length-diameter ratio of 20:1 and a compression ratio of 2.8:1, setting the barrel temperature in four zones: the rear zone at 190 - 200 °C, the middle zone at 210 - 220 °C, the front zone at 230 - 240 °C, and the nozzle at 235 - 245 °C, with a PID temperature control accuracy of ±1 °C, and calibrating the screw speed to the range of 80 - 120 rpm.

4. A process for injection molding of ultra-thin wall ABS, according to claim 1, characterized in that: The mold installation includes assembling a hot runner system with a flat fan-shaped gate of 0.8 mm × 0.3 mm, a runner diameter of Φ3.5 mm, the gate distance from the end of the cavity ≤ 15 mm, the depth of the main exhaust groove is 0.02 mm, the depth of the auxiliary exhaust groove on the parting surface is 0.05 mm, the width is 5 mm, and the spacing is 15 mm. Connecting a vacuum pump to maintain a negative pressure of -0.08 MPa, setting the mold temperature in zones: the cavity at 65 ± 1 °C and the core at 63 ± 1 °C, arranging cooling water channels with a diameter of Φ8 mm and a spacing of 15 mm, injecting an ethylene glycol aqueous solution at 20 L / min, with a temperature control accuracy of ±0.5 °C.

5. A kind of ABS ultra-thin wall injection molding process according to claim 1, characterized in that: In the first stage of high-speed filling, start the dynamic pressure closed-loop control system, with an injection pressure of 130 - 150 MPa, the melt filling 90% of the cavity volume at a speed of 300 mm / s, and monitoring the melt front temperature ≥ 210 °C. In the second stage of low-speed compensation, the injection speed is reduced to 150 mm / s, the holding pressure is 30 - 40 MPa, the holding time is 0.8 - 1.2 seconds, and the holding pressure curve is adjusted in real-time through the cavity pressure sensor feedback, with an error of ±0.5 Mpa.

6. The ABS ultra-thin wall injection molding process according to claim 1, characterized in that: The clamping force regulation includes an initial clamping force of 600 t, dynamically compensating ±5% according to the data of the melt peak pressure sensor, and the hydraulic response time ≤ 50 ms.

7. A kind of ABS ultra-thin wall injection molding process according to claim 1, characterized in that: The melt residence management includes that the residence time of the melt in the barrel is ≤ 180 seconds, the screw back pressure is set at 8 - 10 MPa to avoid thermal degradation. The ejection control includes triggering a two-stage ejection program, switching to a high speed of 5 mm / s for demolding after contacting the product at a low speed of 0.5 mm / s, and configuring the density of Φ2 mm nitrided ejector pins ≥ 12 pieces / m 2 , and the stroke error of the ejector rod is ≤ 0.02 mm.

8. The ABS ultra-thin wall injection molding process according to claim 1, characterized in that: The surface passivation includes subjecting electroplated products to hot air circulation treatment at 80°C for 2 hours with humidity ≤ 30%; non-electroplated products are treated in a 500W plasma reaction chamber for 30 seconds with plasma density ≥ 1×10 12 / cm 3 , and the in-line quality inspection includes real-time detection of wall thickness tolerance of ±0.05 mm by a laser scanner, dynamic fine-tuning of ±2°C by a mold temperature compensation system according to warpage data, defect rates of air marks and weld lines are respectively controlled to be ≤ 0.5% and ≥ 90% of the substrate strength, and the MES system records the process stability report of injection pressure slope and mold temperature fluctuation ≤ ±0.3°C.

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