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.