Thermoplastic‐Resin Transfer Molding Technology: Development and Challenges Toward Industrialization

Driven by increasingly stringent international environmental regulations, the automotive industry is investing considerable resources to reduce its carbon footprint. Lightweight design has emerged as a central strategy. This is particularly evident in the growing adoption of thermoplastic polymers for the production of aesthetic and functional parts. For structural applications, reinforced composites based on thermosetting materials have been explored, but with limitations on the recycling of end‐of‐life vehicles. Emerging structural composites based on thermoplastic matrices present a promising solution for a lightweight structural design, but they are still mainly in an experimental development stage. Manufacturing methods such as thermoplastic‐resin transfer molding (T‐RTM) can be a viable technology for manufacturing polyamide 6‐based parts, particularly with continuous fiber reinforcements. This article reviews the current state of the art in T‐RTM and identifies key opportunities, challenges, and research directions. The main recommendations are the development of new precursors with reduced sensitivity to moisture and oxygen, the design of new specific resin homogenization systems, deeper research into the complex polymerization process and improvements in injection and molding systems, as well as in sustainable recyclability strategies tailored to thermoplastic composites. Addressing these aspects is crucial for the industrial viability of T‐RTM in the automotive sector.