scholarly journals A Novel Multiscale Methodology for Simulating Droplet Morphology Evolution during Injection Molding of Polymer Blends

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 133
Author(s):  
Lin Deng ◽  
Suo Fan ◽  
Yun Zhang ◽  
Zhigao Huang ◽  
Shaofei Jiang ◽  
...  
Keyword(s):  
Injection Molding ◽  
Polymer Blends ◽  
Critical Role ◽  
Pressure Sensors ◽  
Underlying Mechanism ◽  
Mold Filling ◽  
Morphology Evolution ◽  
Filling Process ◽  
Molded Parts ◽  
Droplet Morphology

The morphology of polymer blends plays a critical role in determining the properties of the blends and performance of resulting injection-molded parts. However, it is currently impossible to predict the morphology evolution during injection molding and the final micro-structure of the molded parts, as the existing models for the morphology evolution of polymer blends are still limited to a few simple flow fields. To fill this gap, this paper proposed a novel model for droplet morphology evolution during the mold filling process of polymer blends by coupling the models on macro- and meso-scales. The proposed model was verified by the injection molding experiment of PP/POE blends. The predicted curve of mold cavity pressure during filling process agreed precisely with the data of the corresponding pressure sensors. On the other hand, the model successfully tracked the moving trajectory and simulated morphology evolution of the droplets during the mold-filling process. After mold-filling ended, the simulation results of the final morphology of the droplets were consistent with the observations of the scanning electron microscope (SEM) experiment. Moreover, this study revealed the underlying mechanism of the droplet morphology evolution through the force analysis on the droplet. It is validated that the present model is a qualified tool for simulating the morphology evolution of polymer blends during injection molding and predicting the final microstructure of the products.

scholarly journals Tie-Bar Elongation Based Filling-To-Packing Switchover Control and Prediction of Injection Molding Quality

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1168 ◽  
Author(s):  
Jian-Yu Chen ◽  
Chun-Ying Liu ◽  
Ming-Shyan Huang
Keyword(s):  
Injection Molding ◽  
Pressure Sensors ◽  
Clamping Force ◽  
Cavity Pressure ◽  
Testing Specimen ◽  
Injection Speed ◽  
Novel Approach ◽  
Pressure Profiles ◽  
Molded Parts ◽  
Short Shot

Filling-to-packing switchover (also called V/P switchover) is critical for assuring injection molding quality. An improper V/P switchover setting may result in various defects of injection-molded parts, such as excessive residual stress, flash, short shot, and warpage, etc. To enhance a consistent molding quality, recent V/P switchover approaches adopt cavity pressure profiles requiring sensors embedded in mold cavities, which is invasive to mold cavities and more expensive. Instead of using cavity pressure sensors, by working with the most popular screw position switchover control, this study hereby proposes a novel approach of tuning V/P switchover timing using a tie-bar elongation profile. In this investigation, a dumbbell testing specimen mold is applied to verify the feasibility of the method proposed. The results show that the mold filling and packing stages can be observed along the tie-bar elongation profile, detected by mounting strain gauges on the tie bars. Also, the characteristics of the cavity pressure are similar to those of the tie-bar elongation profile under a proper clamping force condition. Moreover, the varying process parameter settings which include injection speed, V/P switchover point, and holding pressure, can be reflected in these profiles. By extracting their characteristics, the application of the V/P switchover is proved to be realistic. This research conducted an experiment to verify the proposed V/P switchover decision method based on the tie-bar elongation profile. The result showed that the fluctuation of the part’s weight corresponding to a slight change of the barrel’s temperature from 210 °C to 215 °C can be successfully controlled with this method. Besides, the maximum clamping force increment extracted from the tie-bar elongation profile was found to be a good indicator for online monitoring of the reground material variation.

Dynamic modeling of the mold filling process in an injection molding machine

1991 ◽  
Vol 31 (19) ◽  
pp. 1417-1425 ◽  
Author(s):  
Cheng-Ping Chiu ◽  
Laming-Chang Shih ◽  
Jong-Hwei Wei
Keyword(s):  
Injection Molding ◽  
Dynamic Modeling ◽  
Mold Filling ◽  
Filling Process ◽  
Molding Machine ◽  
Injection Molding Machine

scholarly journals Multiscale Modeling and Simulation of Polymer Blends in Injection Molding: A Review

Polymers ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3783
Author(s):  
Lin Deng ◽  
Suo Fan ◽  
Yun Zhang ◽  
Zhigao Huang ◽  
Huamin Zhou ◽  
...  
Keyword(s):  
Injection Molding ◽  
Modeling And Simulation ◽  
Polymer Blends ◽  
Multiscale Modeling ◽  
Technological Development ◽  
Future Research ◽  
Morphology Evolution ◽  
Immiscible Polymer Blends ◽  
Injection Molding Simulation ◽  
Pros And Cons

Modeling and simulation of the morphology evolution of immiscible polymer blends during injection molding is crucial for predicting and tailoring the products’ performance. This paper reviews the state-of-the-art progress in the multiscale modeling and simulation of injection molding of polymer blends. Technological development of the injection molding simulation on a macroscale was surveyed in detail. The aspects of various models for morphology evolution on a mesoscale during injection molding were discussed. The current scale-bridging strategies between macroscopic mold-filling flow and mesoscopic morphology evolution, as well as the pros and cons of the solutions, were analyzed and compared. Finally, a comprehensive summary of the above models is presented, along with the outlook for future research in this field.

Morphology Evolution of Polymer Blends under Intense Shear During High Speed Thin-Wall Injection Molding

2017 ◽  
Vol 121 (25) ◽  
pp. 6257-6270 ◽  
Author(s):  
Yi Zhou ◽  
Feilong Yu ◽  
Hua Deng ◽  
Yajiang Huang ◽  
Guangxian Li ◽  
...  
Keyword(s):  
Injection Molding ◽  
Polymer Blends ◽  
High Speed ◽  
Morphology Evolution ◽  
Thin Wall ◽  
Wall Injection ◽  
Intense Shear
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