Experimental and analytical investigation on resin impregnation behavior in continuous carbon fiber reinforced thermoplastic polyimide composites

Abstract

In molding of carbon fiber reinforced thermoplastics (CFRTP), resin impregnation behavior to fiber yarns is very important because higher viscosity of molten thermoplastics inhibites resin impregnation to the interspace among fibers. Resultant resin un-impregnation causes lower mechanical properties of CFRTP. The purpose of this study was to clarify the relation among molding method, molding conditions and resin impregnation to fiber yarns experimentally and analytically. In this study, CFRTPs using continuous carbon fiber yarn as a reinforcement and a thermoplastic polyimide which is excellent in heat resistance as a matrix resin were produced by Micro-Braiding, Film Stacking and Powder method. In addition resin impregnation was modeled based on Darcy's law and continuity condition. As a result, analytical resin impregnation prediction showed good agreements with the experimental results in all the producing methods and molding conditions. In addition, the void content in the molded CFRP could be greatly reduced by pressurizing cooling.

Influence of composite preform fabrication on the integrity of poly‐aryl‐ether‐ketone matrices

“…The final void content is already low after pre‐impregnation, but in return, the resulting product is stiff which limits its drapeability. Most of the literature describing the various thermoplastic composite preforms focuses on the impregnation behavior, and conclude about the improvement of preforms processability when using advanced semi‐finished products combining both phases 4 . However, only few articles effectively compare the processability of different preform architectures with the same matrix, and even fewer actually deal with high‐performance thermoplastic matrices 16,17 . The influence of polymer transformation from the raw pellet state to its final shape is therefore never considered, even though a transformation at the molten state is always required during the preparation of complex semi‐finished products.…”

“…4 However, only few articles effectively compare the processability of different preform architectures with the same matrix, and even fewer actually deal with high-performance thermoplastic matrices. 16,17 The influence of polymer transformation from the raw pellet state to its final shape is therefore never considered, even though a transformation at the molten state is always required during the preparation of complex semi-finished products. Modification of polymers integrity after extrusion operation has already been reported for many polymers.…”

Mechanical Properties, Melting and Crystallization Behaviors, and Morphology of Carbon Nanotubes/Continuous Carbon Fiber Reinforced Polyethylene Terephthalate Composites

“…The main difference between cCFRTP composites and traditional thermoplastic composites is that the fibers of the former exist continuously in the whole material system, while the fibers of the latter are discontinuous. Therefore, the mechanical properties of cCFRTP composites are better than those of traditional discontinuous fiber reinforced composites [ 3 ], and the application prospect is wider. The continuous fiber characteristics of cCFRTP composites determine that they are highly anisotropic, so it allows various directional performance reinforcement designs.…”

Ionic cross-linked methacrylic copolymers for carbon fiber reinforced thermoplastic composites

“…Various methods have been researched for the fabrication of CFRTPs to achieve good impregnation of the thermoplastic polymer into the carbon fiber bundles. For continuous fiber filaments, the film stacking method [21,22,26], powder impregnation method [22][23][24]26], and microblade method [25,26] have been developed. However, the high viscosity of the polymers in any of the fabrication methods often prevents impregnation, which influences the mechanical properties of the resultant CFRTPs.…”

“…However, the high viscosity of the polymers in any of the fabrication methods often prevents impregnation, which influences the mechanical properties of the resultant CFRTPs. Therefore, researchers have investigated suitable materials and molding conditions, such as pressure, temperature, and molding time, for the manufacture of high-quality CFRTPs [21][22][23][24][25][26][27][28]. Li et al [23] reported two types of PEEKs with different melt flow rates; the polymer viscosity influenced the fiber distribution and mechanical properties.…”