科盛科技實習技術報告-應用數值分析及實務探索GMT與聚氨酯等輕量化材料製程機理之研究

本次以實習生身分進入科盛科技公司進行產業實習，透過一年的實習，讓我能更了解真實產業中的運作模式；另外，在實習過程中能將該產業一部份的相關內容當成碩士論文主題進行研究探討。科盛科技公司推出的Moldex3D模流分析軟體主要應用在射出成型的產業中，Moldex3D透過整合材料的黏度特性、機械性質、熱性質，…，等特性，並藉由數學模型計算來預測加工過程的結果。然而隨著工業發展，塑料加工業中開始研製新材料和新製程，因此科盛公司開始整合研發中心，以及建立數據庫，將Moldex3D逐漸運用到智慧製造發展工業4.0。而我在實習時是進入材料量測中心，量測中心主要是提供材料分析的報告、建立材料資料庫和新式材料的研究。近年來，全球對於能源危機有極大的關注，而產業試著以輕量化來因應此問題，基於輕量化的需求上升，產業開始尋找高性能的塑料取代金屬來製造產品，由於塑料密度遠低於金屬，能有效達到降低產品重量的目的。因此本研究以纖維複材和多孔性材料進行分析與探究，然而這些材料通常含有複雜的機理，造成加工上的困難，也因此不易掌握其材料特性，為此我們有別以往的量測方式，嘗試以不同的量測手段來量測其材料的性質，其中分為兩大研究部份，第一部份為熱塑性玻璃纖維氈(GMT)在壓縮成型製程中纖維-熔膠分離與黏彈特性變化之研究，我們透過壓縮系統來研究GMT的纖維分離現象以及嘗試比較流變系統和壓縮系統的差異，結果顯示GMT在經過壓縮時會造成纖維與基材分離的現象，當壓縮速率愈快，分離現象也愈明顯。另外，我們利用純料比較壓縮流變系統與旋轉流變系統對於量測材料黏彈性之間的差異，透過旋轉流變儀取得材料黏度性質後，接著將結果導入Moldex3D R16的壓縮製程模組中，再將模擬結果和實驗進行對較，結果顯示兩者的結果趨勢相似。然而，我們所得模擬分析與實驗結果趨勢雖然一致，但絕對量值差異頗大，經溫控校正後發現壓縮系統的實際溫度與設定溫度具有一段落差，此部份應該是差異最主要來源。第二部份為應用數值模擬分析與實務驗證探索聚氨酯發泡內在機理以及成型條件對其影響之研究，現今許多高分子都能製造成發泡體，但在眾多高分子材料之中聚氨酯(Polyurethane，PU)一直是備受關注的類型之一，由於它具備廣泛的物理特性和優異的化學性質，使其應用相當廣泛。而聚胺酯發泡主要是透過水和異氰酸酯的反應所產生的二氧化碳所形成；同時異氰酸酯也與多元醇反應，產生聚合物，兩者相互搭配的情況下形成發泡體。然而，相關配方往往是材料商的機密，一般無法得知，故此類發泡機理很難掌握。因此本研究的重點先從探討不同模具溫度對於發泡過程的變化的影響起動，並以市場購得之原始材料作為標準，再針對實驗中個別參數予以變化，討論不同模溫對發泡結果的變化趨勢，以此作為應用上的參考；之後，藉由搭配Moldex3D R17的輔助來進行模擬分析發泡過程，探索不同實驗參數下對於交聯與發泡反應之間的關係，其中包括分析發泡結果的高度、核心溫度以及探討轉化率的關係。結果顯示，溫度是影響發泡的重要因素之一，而模具尺寸則影響甚微。另外，溫度的影響來自模溫以及反應時所造成的放熱，這些溫度會直接影響發泡系統的溫度，而當溫度愈高時，會造成發泡交聯轉化速率的提升以及會使發泡高度愈高。

關鍵字

科盛科技(Moldex3D) ；玻璃纖維氈(GMT) ；壓縮製程；纖維-熔膠分離作用；黏彈特性； PU發泡；化學發泡

並列摘要

I joined Moldex3D as an intern. The year's internship has made me realize the workplace's operation mode in better way. In this practical report, there are two major parts. For one thing, basic research result in my first year of Master program. For another thing, my practical training report in my second year of Master program. The inspiration for this study is related to lightweight technology. In recent years, the energy crisis has been a very attention issues by global world. People have tried to reduce this problem by lightweight technology. Based on the rising demand for light weight, the industry began to look for high-performance plastics to replace metals to manufacture products. Since the density of plastics is much lower than metals, it can effectively achieve the purpose of reducing product weight. The overall objective of this study is focused on the fiber composite and porous materials and the related technologies. However, these materials usually contain complex mechanisms, which cause difficulties in processing. Therefore, it is quite difficult to grasp the characteristics of materials. Hence, we have tried to get the properties of materials with different measurement methods. For better understanding, this report has been divided into two parts. The first part is “Study on the fiber-matrix separation phenomena of the glass mat thermoplastics (GMT) and its effect on viscoelasticity variation in compression molding”. We have applied the compression molding to study the fiber separation phenomenon of GMT. The results indicated that when GMT is compressed, the fiber-matrix separation phenomena happened. Moreover, when the pure PA material was applied, the difference on the viscoelasticity of the material using the compression rheological system and the rotational rheological system has been conducted. We obtained the material viscosity properties through a rotary rheometer, and then imported the properties into the Moldex3D R16 compression process module, and finally compared the simulation results with the compression experiment. The findings of the research have led to the conclusion that the simulation and compression experiments have the same trend. However, the results of the loading force of the two systems are quite different. The main difference is coming from the temperature control unit of the compression system. Moreover, the second part of this report is “Numerical simulation and experimental study on the internal mechanism of the polyurethane foaming and the influence of the operation condition”. PU foam is a kind of chemical foaming, and its foaming is created by carbon dioxide generated by the reaction of water and isocyanate. To discover the mechanism of PU foaming, we have tried to study the material property changes during the foaming process. Specifically, we focused on the mold temperature effect on the foaming process. We applied the materials in the market, and then tried to test various parameters. Moreover, we have utilized Moldex3D R17 to conduct the relationship between crosslinking and foaming reaction under different experimental parameters in the foaming process, including the height of the foaming, the inner temperature of formed part and the conversion rate. The research conducted suggests that temperature is one of the most important factors affecting foaming process, while mold size has little effect. The influence of temperature comes from the mold temperature and the exotherm generated by the reaction.

並列關鍵字

CoreTech System (Moldex3D) Co., Ltd., ； Birefringence ； Viscoelastic models ； Photoelasticity ； Squeeze flow ； Compression molding ； Glass mat thermoplastic/GMT