Resin transfer molding is a process where reinforcing material is manually placed into a mold. The mold is then closed and resin is injected into it.
The manual nature of the resin transfer molding process allows for almost any reinforcing material to be considered, chopped strand or mat. Similarly, the resin and catalyst blend can be manipulated to allow for ideal processing conditions.
A core and cavity are necessary for RTM. Tools can be made from composite materials or aluminum.
RTM parts can be made with very good surface finishes, on either side. Typically a gel coat will be introduced into the process to achieve better finishes.