射出成型技術應用於燃料電池雙極板碳纖分佈之研究

Study on the Injection Molding Technology for Fuel Cells Bipolar Plates with Carbon Fiber Distribution

李平惠(P. H. Lee) ； 洪啟仁(C. R. Hung)

《南亞學報》 26期 (2006/12) Pp. 37-52

https://doi.org/10.6989/JN.200612.0037

摘要

在本研究中，選用添加4%碳纖之PC高分子複合材料，利用長寬各50 mm與厚2mm且含流道之平板狀模仁，針對不同的射出速度（50、65 以及80 mm/s三種射出速度）與流道配置方向（分別垂直與平行充填方向）來成型雙極板成品，並以掃描式電子顯微鏡（SEM）沿厚度方向上對纖維孔洞數做一量測與分析，藉以探討射出速度與流道配置方向對纖維分佈的影響。研究結果顯示，在各種熔膠射出速度的情況下，除了非常接近近澆口端與充填末端的纖維含量均非常少之外，而其餘成型品部分則當射出速度較低時（50 mm/s），纖維由近澆口端至充填末端分佈較為均勻。當射出速度由50增加至65以及80 mm/s時，纖維含量會由近澆口端之較多含量而逐漸向充填末端處減少（即分佈愈不均勻），因此射速對於纖維分佈會有明顯的影響，速度慢時有較好的分佈性。而在流道的配置方面，當流道垂直於充填方向時，會使纖維產生翻滾而糾結在一起，因此相較於流道平行於充填方向的成型品相比，可提升整體電導度。本研究結果，可提供相關業者在雙極板流道佈置與進澆口位置設計時一重要參考準則。

關鍵字

燃料電池 ； 雙極板 ； 射出成型 ； 碳纖

並列摘要

In this study, there are two designs of mold insert that one is a flat insert, the other is channel insert and the material is polycarbonate blended with 4% carbon fiber. For studying fiber distribution, the bipolar plate was molded using different filling velocity (50mm/s, 65mm/s and 80mm/s) and channel layout direction, and the fiber distribution along the thickness-direction was measured by SEM to investigate the influence of filling velocity and channel layout on distribution. By obtaining the best fiber distribution at the results of previous experiment, influence of filling velocity and channel layout on resistance was investigated using polystyrene blended with 30% carbon fiber. The relationship between fiber distribution and resistance was studied.From the results, the fiber distribution is uniform at low velocity (50mm/s), but the low concentrations of conductive fiber appear near gate and at the end of flow for all kinds of filling velocity. As filling velocity raises to 60 mm/s or 80 mm/s, the concentrations graduately reduce from gate to end of flow. Therefore the filling velocity influences fiber distribution. On the channel layout, as channel is perpendicular to filling direction, the fibers are rolled and banded together, and the conductivity can be improved about 50% compared with channel parallel to filling direction. This study can offer guide lines of channel layout and gate position for bipolar.

並列關鍵字

Fuel cell ； bipolar plate ； injection molding ； carbon fiber