Parametric study of an automated nanoparticles spray process for nanofibers/fabric reinforced composites

The most common technique in introducing nanoparticles into polymer composites involves mixing the nanoparticles with the matrix. However, in liquid molding processes nanoparticles filtration through the distribution medium and the reinforcement fabrics, during the mold filling stage, results in a poorly controlled and inconsistent distribution of the nanoparticles throughout the part with some uncertainty about the actual amount of the nanoparticles in the molded material. In this study, a straightforward, yet effective automated spray process was developed and tested. Three influential spray parameters, including spray velocity, air pressure and the number of sprayed layers, were chosen and investigated to study their effects quantitatively on sprayed carbon nanofibers (CNFs) dosage (areal density). The processing parameter‐induced–performance relationship was established according to experimental design. A regression model and process maps were developed to relate the process parameters to the sprayed dosage using the developed process. To study, qualitatively, the influence of spray parameters on the deposited CNFs morphology, the sprayed fabrics were characterized using optical microscope. POLYM. COMPOS., 40:1068–1077, 2019. © 2018 Society of Plastics Engineers