Resin transfer moulding machines

Boatbuilding techniques

Large composite structures can be produced using a vacuum assisted resin transfer moulding process. The structures incorporate cores, which may be hollow cells or foam blocks.

A plurality of cores, each of which may be wrapped with a fibre material, is arranged in a layer on a mould with the fibre material arranged to form face skins. The assembly is sealed under composite process vacuum bagging to a mould surface.

One or more main feeder conduits are provided in communication with a resin distribution network of smaller channels which facilitates flow of uncured resin into and through the fibre material.

The resin distribution network may comprise a network of grooves formed in the surfaces or the cores and/or rounded corners of the cores. The network of smaller channels may also be provided between the vacuum bag and the fibre material, either integrally in the vacuum bag or via a separate distribution medium.

Resin, introduced under vacuum,travels relatively quickly through the main feeder channel(s) and the network of smaller channels.

After penetrating the fibre material to reach the surface of the cores, the resin again travels relatively quickly along the cores via the grooves in the cores or the spaces provided by the rounded corners to penetrate the fibre material between the cores, if present, and between the cores and the mould.

Complex carbon fibre composites  

Araldite resin transfer moulding systems are being used by Fischer Composite Technology to produce stylish carbon composite side blades on Audi's latest high performance sports car.

Huntsman Advanced Materials said that Fischer Composite Technology, based near Salzburg, Austria, specialises in the development and production of complex carbon fibre composites for use in the automotive, aerospace and sports leisure equipment industries.

In a recent project for Audi AG, Fischer worked closely with Huntsman Advanced Materials using Araldite Resin Transfer Moulding (RTM) and specialist bonding technologies to manufacture carbon side blades on the Audi R8 sports car

Measuring 900mm x 500mm, the side blade is made from two RTM shells which are later bonded together using Araldite 2015.

This is a two-component epoxy adhesive paste with a highly resilient bond. The Araldite 2015 bond is sag resistant up to 10mm and is particularly suitable for SMC and GRP bonding applications, said Huntsman.

Moulding techniques - during the Araldite RTM process to produce the side blade, some dry pre-formed carbon fibres are put into a mould and injected with epoxy resin.

The inner shell is cast with all the fixing devices to mount the side blade on to the car already in place, so no additional auxiliary component bonding or finishing is required.

The outer shell comprises a three-layer CFK/GFK structure.

Once mounted, the visible outer side of the side blade is a 6K Twill 2/2 carbon fibre surface, protected from UV sunlight with a clear, glossy lacquer finish.