The in-mold coating (IMC) process nowadays is well accepted by the sheet molding compound industry. The currently used IMC contains 2.8 wt% carbon black (CB) to provide enough electrical conductivity for maximum paint transfer efficiency (PTE) for electrostatic painting. Due to its relatively large viscosity, this formulation makes use of more than one injection gate for coating some large parts necessary. Our previous research investigated the possibility to replace the CB with higher conductivity carbon-based nanoparticles, namely carbon nanofibers (CNFs), multi-wall carbon nanotubes (MWCNTs), industrial graphene (grapheneblack [G]), and single-wall carbon nanotubes (SWCNTs) and found that the IMC with 11.3 wt% G has the best processability among all IMC formulations. To improve this formulation, herein, we study the use of a second reinforcement in combination with G, i.e., CB, CNF, and MWCNT. Results from this study suggest that most G/CB-reinforced IMC formulations have a better performance than the G-reinforced IMC formulations, and IMC with 1 wt% CB and 6 wt% G is the best among all G/CB-reinforced IMC formulations. To be specific, the new formulation allows parts to be painted to have a 300% increase in size when compared with the standard IMC.

中文翻译：

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提高模内涂层配方的可加工性：第二部分：两种增强剂配方

如今，模内涂层 (IMC) 工艺已被片状模塑料行业广泛接受。目前使用的 IMC 含有 2.8 wt% 的炭黑 (CB)，以提供足够的导电性，以实现静电喷漆的最大油漆转移效率 (PTE)。由于其相对较大的粘度，该配方使用多个注射浇口来涂覆一些必要的大型零件。我们之前的研究调查了用更高导电性的碳基纳米粒子代替 CB 的可能性，即碳纳米纤维 (CNFs)、多壁碳纳米管 (MWCNTs)、工业石墨烯 (grapheneblack [G]) 和单壁碳纳米管。 SWCNTs)，并发现在所有 IMC 配方中，含 11.3 wt% G 的 IMC 具有最佳的可加工性。为了改进这个配方，在此，我们研究了与 G 结合使用的第二种增强材料，即 CB、CNF 和 MWCNT。这项研究的结果表明，大多数 G/CB 增强的 IMC 配方比 G 增强的 IMC 配方具有更好的性能，1 wt% CB 和 6 wt% G 的 IMC 是所有 G/CB 增强的 IMC 配方中最好的. 具体来说，与标准IMC相比，新配方允许涂漆的零件尺寸增加300%。