Driven by the need for more cost-effective applications, researchers and design engineers of polymer composites are facing increasing demands for the development of faster and more environment-friendly processing methods. Rapid processing techniques require a better understanding and a more efficient control of phenomena such as heating, impregnation, bonding and solidification. Most of the new techniques promote non-isothermal and transient phenomena in order to achieve faster transformation of the materials. Material physical properties, material microstructure and processing conditions set the theoretical limits for rapid processing. The time scales of the material phenomena controlling the processing of thermoplastic composites are presented. It is shown for example, how novel composite microstructures influence the consolidation time, or how the fusion bonding time can be reduced when non-isothermal conditions are promoted. Furthermore, the application of the results to a novel integrated processing technology illustrates the new potentials of thermoplastic composites. The description of the phenomena controlling the processing rate is useful, knowing that better tailoring and control of the material transformation, adaptation of the material constituents, and combination of process sequences are intensively required for the development of more efficient manufacturing routes for composites.