Deng Lin, Fan Suo, Zhang Yun, Huang Zhigao, Jiang Shaofei, Li Jiquan, Zhou Huamin
School of Mechanical and Electrical Engineering, Wuhan Institute of Technology, Wuhan 430074, China.
State Key Laboratory of Material Processing and Die & Mold Technology, Huazhong University of Science and Technology, Wuhan 430074, China.
Polymers (Basel). 2020 Dec 30;13(1):133. doi: 10.3390/polym13010133.
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.
聚合物共混物的形态在决定共混物性能和注塑成型部件的性能方面起着关键作用。然而，目前尚无法预测注塑成型过程中的形态演变以及成型部件的最终微观结构，因为现有的聚合物共混物形态演变模型仍局限于少数简单的流场。为了填补这一空白，本文通过耦合宏观和介观尺度的模型，提出了一种用于聚合物共混物充模过程中液滴形态演变的新模型。通过PP/POE共混物的注塑成型实验对所提出的模型进行了验证。充模过程中模腔压力的预测曲线与相应压力传感器的数据精确吻合。另一方面，该模型成功地跟踪了液滴在充模过程中的移动轨迹并模拟了其形态演变。充模结束后，液滴最终形态的模拟结果与扫描电子显微镜（SEM）实验的观察结果一致。此外，本研究通过对液滴的受力分析揭示了液滴形态演变的潜在机制。验证了本模型是模拟聚合物共混物注塑成型过程中形态演变和预测产品最终微观结构的合格工具。
