A large number of composite fabrication methods are in use today. Thy include, autoclave, vacuum bag, and compression molding, filament winding, fiber placement, injection molding, pultrusion, resin transfer molding (RTM), and vacuum assisted resin transfer molding (VARTM). A major activity at the IPC Center at Northwestern University involves the RTM and VARTM processes.

The RTM process consists of the following steps:

1. Preparation of preform, or "skeleton" of dry fiber reinforcement;
2. Placement of perform in a specially designed mold to provide for resin injection and venting and optimized resin flow;
3. Resin metering, mixing, heating and injection into closed mold;
4. Application of time-termperature curing cycle;
5. Removal of part from mold and evaluation ( physical, mechanical and nondestructive ).

RTM Process
	Preform	Reinforcement assembly forming skeleton of structure
	Tool	Mold designed to provide for resin injection, venting and optimized resin flow
	Injection	Resin metering, mixing, heating and injection
	Cure	Prescribed time-temperature cure cycle
	Demold	Removal of part