The three development trends of carbon fiber reinforced thermoplastics.

As the application market continues to expand, thermosetting resin-based carbon fiber composite materials have increasingly shown their limitations, failing to fully meet high-end application demands for wear resistance and high temperature resistance. Under these circumstances, thermoplastic resin-based carbon fiber composite materials have risen in prominence, emerging as a force in advanced composites. In recent years, significant advancements have been made in domestic carbon fiber technology, further advancing the application technology of thermoplastic carbon fiber composites.

The exploration in continuous carbon fiber reinforced thermoplastic prepregs vividly illustrates three trends in the use of thermoplastic carbon fibers:

The first trend is the shift from powder carbon fiber reinforcement to continuous carbon fiber reinforcement: Carbon fiber thermoplastic composite materials can be categorized by the type of reinforcing fibers, including powder carbon fiber, chopped carbon fiber, unidirectional continuous carbon fiber, and woven carbon fiber reinforcement. When composite materials undergo bending or shear failure, fibers are extracted from the matrix. The longer the reinforcing fibers, the more energy they can absorb from the applied load during extraction, leading to increased overall material strength. Consequently, continuous carbon fiber reinforced thermoplastic composites offer superior performance compared to those made with powder or chopped carbon fiber. The injection molding process widely employed in China still utilizes powder or chopped carbon fiber reinforcement, limiting product performance. However, the adoption of continuous carbon fiber reinforcement opens up broader application possibilities for thermoplastic carbon fiber composite materials.

The second involves the advancement from low-end to mid-to-high-end thermoplastic resin matrices: During the melting process, thermoplastic resin matrices display high viscosity, making it typically challenging to adequately infuse with carbon fiber materials. The level of infusion is intimately linked to the performance of the prepreg. To enhance infusion, composite modification techniques were employed, along with refinements to the original fiber spreading and resin extrusion equipment. These modifications expanded the width of the carbon fiber precursor bundles while simultaneously increasing the resin’s continuous extrusion rate, markedly enhancing the resin’s ability to infuse with carbon fibers and effectively securing the performance of continuous carbon fiber-reinforced thermoplastic prepregs. The resin matrix of continuous carbon fiber thermoplastic composites was successfully advanced from low-end resins like PPS and PA to mid-to-high-end resins such as PI and PEEK.

The third stage involves transitioning from laboratory-scale crafting to stable mass production: The most critical aspect in the transition from successful small-scale laboratory experiments to stable, large-scale production in the workshop is the design and adjustment of production equipment. The ability to achieve stable mass production of continuous carbon fiber reinforced thermoplastic prepreg hinges not only on the daily output but, more importantly, on the consistency of the prepreg’s quality. This includes ensuring the resin content is manageable and properly proportioned, the carbon fibers are evenly distributed and thoroughly saturated, and the prepreg has a smooth surface and precise dimensions. To balance quality and quantity, Carbon (Xiamen) New Material Co., Ltd. spent three years making hundreds, possibly thousands, of adjustments to reach the ultimate goal of stable mass production. Currently, the width of the mass-produced continuous carbon fiber reinforced thermoplastic prepreg can range from 40 to 60 cm.