Hand and spray lay up using open moulds are established methods of manufacturing fibreglass composite components of all shapes, sizes and complexity for relatively little capital investment. However, increasing commercial and environmental pressures are driving GRP manufacturers to adopt new production methods such as closed moulding. There are 5 key closed mould processes currently used.

Closed mould processes

Scott Bader is dedicated to the continued development of closed mould processing. Technical expertise and a dedicated range of Crystic® polyester products are available for the following closed mould techniques:

• Vacuum Injection : A simple, adaptable process, which uses a flexible film and traditional GRP moulds. Suitable for making prototypes or 1-2 components per day.

• VacFlo : A cost effective entry into closed mould processing. The capital investment needed is low, due to the utilisation of lightweight, matched, GRP tools. Suitable for making up to 5 components per day.

• RTM Light : An extension of the VacFlo process using similar mould design principles. The use of an injection machine to introduce resin into the mould further controls the process. Suitable for making up to 8 components per day.

• Resin Transfer Moulding (RTM) : A fast and efficient way of producing FRP parts. The process involves the controlled injection of resin through dry reinforcement placed in a rigid, matched, temperature controlled, composite or metal tool. Suitable for making up to 40 components per day.

• Crystic® SMC & Impreg® LPMC: Scott Bader's range of Sheet Moulding Compounds and Low Pressure Moulding Compounds compliment the liquid moulding techniques previously described. These thermoset compounds offer fast cycle times and a more automated process for high volume composite applications. Suitable for making up to 250 components per day.