The Improvement Effect and Mechanism of Longitudinal Ultrasonic Vibration on the Injection Molding Quality of a Polymeric Micro-Needle Array

Gao, Shan; Qiu, Zhongjun; Ouyang, Junhao

doi:10.3390/polym11010151

Cited by 9 publications

(5 citation statements)

References 27 publications

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“…Ultrasonic processing technology, as a novel molding processing technology, has been widely used in recent years for the injection molding, extrusion molding, and compression molding of polymers [9,10]. Despite different ways of applying ultrasonic energy, studies have found that ultrasounds can affect the microstructure filling performance [11], change the material properties [12], affect the extrusion swelling [13], improve the weld line strength of the plastic parts [14], and reduce the interface friction during ejection [15]. However, current studies are mainly based on experiments.…”

Section: Introductionmentioning

confidence: 99%

Micro-Ultrasonic Viscosity Model Based on Ultrasonic-Assisted Vibration Micro-Injection for High-Flow Length Ratio Parts

Lou

Xiong

2020

Polymers

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A micro-ultrasonic (MU) viscosity model based on ultrasonic-assisted vibration micro-injection for high- flow length ratio polymer parts was established. This model considered the effects of ultrasonic energy and the characteristic microdimension. Ultrasonic energy parameters (such as the ultrasonic amplitude, frequency, and ultrasound velocity), the characteristic microdimension, and the molecular chain length (MCL) were introduced into the MU viscosity model. An ultrasonic micro-injection experimental platform was built on an injection molding machine. Polypropylene (PP) filling experiments were carried out using microgrooves with different flow length ratios (depth-to-width ratios of 3:1, 5:1, and 10:1). The validity and accuracy of the MU viscosity model were examined through a filling experiment with polypropylene (PP) microgroove injection molding and by a flow pressure difference experiment with polystyrene (PS). The results showed that the MU viscosity model was in better agreement with the experimental results compared to other models. The maximum error of the MU model was 4.9%. Ultrasound-assisted vibration had great effects on the filling capacity for microgrooves with high flow length ratios (depth-to-width ratios greater than 5:1). The filling capacity increased as the ultrasonic amplitude increased.

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Section: Introductionmentioning

confidence: 99%

Micro-Ultrasonic Viscosity Model Based on Ultrasonic-Assisted Vibration Micro-Injection for High-Flow Length Ratio Parts

Lou

Xiong

2020

Polymers

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“…The results were that the filling area of the plastic parts was improved by about 6.91% and symmetric deviation was improved 15.62% on average because of ultrasonic vibration. Lateral experiment and simulation proved it again [ 49 , 59 ]. The improvement of the mass or the filling length of molded parts is related to the temperature change under the action of ultrasonic vibration field.…”

Section: Ultrasound-assisted Micro-injection Moldingmentioning

confidence: 96%

Tuning Power Ultrasound for Enhanced Performance of Thermoplastic Micro-Injection Molding: Principles, Methods, and Performances

Zhao

Qiang

et al. 2021

Polymers

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With the wide application of Micro-Electro-Mechanical Systems (MEMSs), especially the rapid development of wearable flexible electronics technology, the efficient production of micro-parts with thermoplastic polymers will be the core technology of the harvesting market. However, it is significantly restrained by the limitations of the traditional micro-injection-molding (MIM) process, such as replication fidelity, material utilization, and energy consumption. Currently, the increasing investigation has been focused on the ultrasonic-assisted micro-injection molding (UAMIM) and ultrasonic plasticization micro-injection molding (UPMIM), which has the advantages of new plasticization principle, high replication fidelity, and cost-effectiveness. The aim of this review is to present the latest research activities on the action mechanism of power ultrasound in various polymer micro-molding processes. At the beginning of this review, the physical changes, chemical changes, and morphological evolution mechanism of various thermoplastic polymers under different application modes of ultrasonic energy field are introduced. Subsequently, the process principles, characteristics, and latest developments of UAMIM and UPMIM are scientifically summarized. Particularly, some representative performance advantages of different polymers based on ultrasonic plasticization are further exemplified with a deeper understanding of polymer–MIM relationships. Finally, the challenges and opportunities of power ultrasound in MIM are prospected, such as the mechanism understanding and commercial application.

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“…At present, the theory on the effect of vibration on the interior and surface of plastically worked materials is based on two fundamental effects [ 23 , 24 ]. That is, the volume effect that affects the mechanical properties and the surface effect that affects the sliding friction.…”

Section: Introductionmentioning

confidence: 99%

Mechanism Study of Ultrasonic Vibration-Assisted Microgroove Forming of Precise Hot-Pressed Optical Glass

et al. 2023

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Microgroove structures with helical pitches in a wavelength level are increasingly required in optical areas. However, conventional manufacturing techniques generate relatively high stresses during pressing, resulting in poor precision when forming microgrooves. This paper reports on the mechanism of the ultrasonic vibration-assisted microgroove forming of precise hot-pressed optical glass. A finite element (FE) thermocompression model of the viscoelastic material was developed and the entire forming process was numerically simulated using coupled thermal-structural analysis. The analysis of several process parameters was carried out using orthogonal experiments, from which the optimum combination of parameters was selected. The glass thermoforming process is also assisted by ultrasonic vibration. The thermal and mechanical effects of vibration improved material flow and optimized forming results. The average maximum stress in the glass during the forming process was only 3.04 × 10−3 Mpa, while the maximum stress in the hot-pressing stage without ultrasound was 1.648 Mpa. The stress results showed that the material-forming stress is significantly reduced.

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The Improvement Effect and Mechanism of Longitudinal Ultrasonic Vibration on the Injection Molding Quality of a Polymeric Micro-Needle Array

Cited by 9 publications

References 27 publications

Micro-Ultrasonic Viscosity Model Based on Ultrasonic-Assisted Vibration Micro-Injection for High-Flow Length Ratio Parts

Micro-Ultrasonic Viscosity Model Based on Ultrasonic-Assisted Vibration Micro-Injection for High-Flow Length Ratio Parts

Tuning Power Ultrasound for Enhanced Performance of Thermoplastic Micro-Injection Molding: Principles, Methods, and Performances

Mechanism Study of Ultrasonic Vibration-Assisted Microgroove Forming of Precise Hot-Pressed Optical Glass

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