Resin transfer moulding; RTM allows the moulding of components which have complex shapes and large surface areas with a good surface finish on both sides. The process is suited to short and medium runs and is employed in many transport applications such as truck cabs. This process consists of placing reinforcements in the mould before injecting the resin. Polyesters, epoxies, phenolics and acrylics are usually used. Various kinds of moulds are used, and heat may be applied to assist the cure, in which case a steel mould may be necessary. Low profile resins can be used to improve surface finish and appearance. Alternatively, low-pressure RTM allows cheaper composite tooling to be used. The reinforcement can be continuous filament mats or fabrics. The use of preforms from continuous filament strand mats can increase the production rate.

This definition is in context to Textile. See more contextual defintions for Rtm (Composites).