moulding-additive-manufacture > Vacuum Bag Moulding

Vacuum Bag Moulding is a very flexible process. Dry Fibres or Pre-Impregnated (Pre-Preg) Fibres can be used to produce components. Depending on the components being produced, the actual bag can be disposable or reusable. In theory there is no limit on size of components either, all that is required is a more complex vacuum system.

There are two general processes for vacuum bagging, the type of fibres being used drive the process methodology.

Dry Fibres are laid into the female mould and must be wetted before the bag is placed over the mould. Once the bag is secured, a Vacuum is created, forcing the resin to fully impregnate the fibres. Once fully impregnation is achieved, the vacuum pump is switched off, however the pressure difference is maintained within the bag. The component is then left to cure.

Alternatively, if Pre-Preg Fibres are being used, the fibres can be placed in the mould and the bag be immediately secured and vacuum drawn. The is female mould is then heated to activate the resin, the heat and pressure difference is maintained until curing is complete. Or once the vacuum has been created, the whole mould can be placed in an Autoclave where heat and pressure are simultaneously applied. This process is common and is often used to produced high quality parts for Motorsport or aerospace.