RTM is a low pressure moulding process, where a mixed resin and catalyst are injected into a closed mould containing a fibre pack or preform. When the resin has cured the mould can be opened and the finished component removed.
A wide range of resin systems can be used including polyester, vinylester, epoxy, phenolic and methyl methacylates etc, combined with pigments and fillers including aluminium trihydrates and calcium carbonates if required.
The fibre pack can be either, glass, carbon, arimid, or a combination of these. There are a large variety of weights and styles commonly available.
The Advantages and Benefits of using RTM:
Mouldings can be manufactured to close dimensional tolerances
Components will have good surface finish on both sides
Selective reinforcement and accurate fibre management is achievable
Ability to build-in fibre volume fraction loadings up to 65%
Uniformity of thickness and fibre loading, resulting in uniform shrinkage
Inserts may be incorporated into mouldings
Tooling costs comparatively low compared to other manufacturing processes
Uses only low pressure injection
Low volatile emission during processing
Ability to produce near net shape mouldings, reducing material wastage
Process can be automated, resulting in higher production rates with less scrap
Ability to mould complex structural and hollow shapes
Low resultant voidage in moulded components
Ability to achieve from 0.5mm to 90mm laminate thickness