Pre Preg Moulding
This particular form of composite fabrication begins with the pre-impregnation (pre preg) of reinforcement materials with a resin or binder. The combining of these two materials occurs prior to the moulding process and therefore enables a very accurate reinforcement to resin ratio to be achieved.
Pre preg materials are used extensively in the aerospace industry due to their ability to maximize strength to weight ratios.
Pre pregs are pliable and therefore able to be cut into various shapes or patterns prior to processing into moulded products.
The moulding process occurs by rolling these pre preg patterns around a tapered or parallel mandrel. The mandrel forms the internal shape of the moulding. A flexibile outer mould is achieved by wrapping the moulded product with a polypropylene or nylon tape prior to heat curing. Heat curing gives a permanent hard, cross linked composite structure.
Following curing the mandrel and tape are removed leaving the completed moulding. If necessary the completed moulding can be ground, sanded or painted depending upon the final application.