Lin Wei-Chun, Fan Fang-Yu, Huang Chiung-Fang, Shen Yung-Kang, Wang Hao
School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei 110, Taiwan.
Research Center for Biomedical Devices, Taipei Medical University, Taipei 110, Taiwan.
Polymers (Basel). 2022 Apr 30;14(9):1845. doi: 10.3390/polym14091845.
In this study, we determined the effects of design and processing parameters of precision injection molding (PIM) to minimize warpage phenomena of micro-sized parts using various plastics (polyoxymethylene (POM), acrylonitrile-butadiene-styrene (ABS), polypropylene (PP), polyamide (PA), and ABS+ polycarbonate (PC)). We applied a numerical simulation (Moldflow) to determine the runner's balance in multi-cavities of the micro-sized part and simulate the warpage phenomenon of micro-parts with PIM. We used simulation data to fabricate a steel mold by computer numerical control (CNC) machining. In this, we study manufactured a micro-sized part and measured its warpage value using various PIM process parameters (melt temperature, mold temperature, injection pressure, and filling time). In order to obtain optimal results (i.e., minimum warpage), we employed the Taguchi method and grey theory to discern the influence of each process parameter on PIM. Finally, we determined that the most significant PIM process parameter influencing the warpage phenomenon of micro-sized parts was the mold temperature, regardless of whether in terms of the experimental results, numerical simulations, or grey theory. The PA material had the most suitable properties for application for micro-sized parts, regardless of whether in terms of experimental results, numerical simulations, or grey theory for PIM. This study also illustrates that micro-sized parts can be fabricated by PIM without the use of micro-injection molding, and we determined that the mold temperature required for molding does not need to be higher than the glass-transition temperature of the material.
在本研究中，我们确定了精密注射成型（PIM）的设计和工艺参数对使用各种塑料（聚甲醛（POM）、丙烯腈-丁二烯-苯乙烯（ABS）、聚丙烯（PP）、聚酰胺（PA）以及ABS+聚碳酸酯（PC））的微型零件翘曲现象的影响，以将其降至最低。我们应用数值模拟（Moldflow）来确定微型零件多型腔中流道的平衡，并模拟PIM微型零件的翘曲现象。我们利用模拟数据通过计算机数控（CNC）加工制造了一个钢模。在此过程中，我们研究制造了一个微型零件，并使用各种PIM工艺参数（熔体温度、模具温度、注射压力和填充时间）测量了其翘曲值。为了获得最佳结果（即最小翘曲），我们采用田口方法和灰色理论来识别每个工艺参数对PIM的影响。最后，我们确定，无论从实验结果、数值模拟还是灰色理论来看，影响微型零件翘曲现象的最重要的PIM工艺参数都是模具温度。无论从PIM的实验结果、数值模拟还是灰色理论来看，PA材料对于微型零件的应用具有最合适的性能。本研究还表明，微型零件可以通过PIM制造，而无需使用微注射成型，并且我们确定成型所需的模具温度不需要高于材料的玻璃化转变温度。
