Material phenomena controlling rapid processing of thermoplastic composites

Driven by the need for more cost-effective applications, researchers and de sign engineers of polymer composites are facing increasing demands for the development of faster and more environment-friendly processing methods. Rap id processing techniques require a better understanding and a more efficien t control of phenomena such as heating, impregnation, bonding and solidific ation. Most of the new techniques promote non-isothermal and transient phen omena 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 materia l phenomena controlling the processing of thermoplastic composites are pres ented. It is shown for example, how never composite microstructures influen ce the consolidation time, or how the fusion bonding time can be reduced wh en 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 sequenc es are intensively required for the development of more efficient manufactu ring routes for composites. (C) 2001 Elsevier Science Ltd. All rights reser ved.