Surface porosity during vacuum bag-only prepreg processing: Causes and mitigation strategies
Surface porosity during vacuum bag-only prepreg processing: Causes and mitigation strategies
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仅真空袋预浸料加工过程中的表面孔隙：原因和缓解策略
DOI：
10.1016/j.compositesa.2015.04.009
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发表时间：
2015
影响因子：
8.7
通讯作者：
S. Nutt
中科院分区：
文献类型：
--
作者：
Lee Hamill;T. Centea;S. Nutt
在本研究中，我们采用参数化方法结合表面分析来确定表面孔隙的来源并制定有效的缓解策略。结果证实，表面孔隙率主要与铺层过程中工具-预浸料界面处滞留的空气有关。表面孔隙率的大小和分布受到多个参数的影响，包括真空保持时间、冷冻和退出时间以及影响排气的材料和工艺修改。结果表明，预浸料的出胶时间（以及粘性）和真空质量是表面孔隙率的主要驱动因素；例如，仅使用 4 天后，表面孔隙率就下降了 83%，使用 14 天后，表面孔隙率就下降了 99%。这些因素用于制定指导方针，通过（a）增加空气排出的驱动力和/或（b）增加工具-预浸料界面的渗透性来减轻表面孔隙率。
In this study, we employ a parametric approach coupled with surface analysis to identify the source(s) of surface porosity and to develop effective mitigation strategies. Results confirmed that surface porosity was primarily associated with air that was trapped at the tool–prepreg interface during layup. The magnitude and distribution of surface porosity was affected by multiple parameters, including vacuum hold time, freezer and out time, and material and process modifications that affect air evacuation. The results indicated that prepreg out time (and thus tack) and vacuum quality were the primary drivers of surface porosity; for example, surface porosity decreased by 83% after just four days of out time and by 99% after 14 days of out time. These factors were used to formulate guidelines to mitigate surface porosity by (a) increasing the driving force for air evacuation and/or (b) increasing the permeability of the tool–prepreg interface.