Method and moulding system for manufacturing a fibre-reinforced polymer object via a feedback system for controlling resin flow rate

A method of manufacturing a fibre-reinforced polymer object by means of vacuum-assisted resin transfer moulding (VARTM), wherein fibre material is impregnated with liquid resin in a mould cavity comprising a rigid mould part having a mould surface defining an outer surface of the object, said method comprising the following steps:

• a) arranging a fibre lay-up including a number of fibre layers on the mould surface,
• b) arranging at least one resin inlet above the fibre lay-up,
• c) attaching one or more pressure sensors to or near the at least one resin inlet,
• d) arranging a vacuum bag on top of the rigid mould part and sealing the vacuum bag to the mould part to define the mould cavity,
• e) evacuating the mould cavity,
• f) supplying liquid resin to the mould cavity so as to impregnate the fibre lay-up,
• g) monitoring the pressure and generating a signal indicative of said pressure,
• h) feeding said signal back to a control unit that controls a resin flow rate supplied to the resin inlets,
• i) increasing a resin flow rate, if the pressure measured by the pressure sensors at the resin inlet drops below a lower threshold level, and decreasing the resin flow rate, if the pressure measured by the pressure sensors at the resin inlet is above a higher pressure threshold, and
• j) allowing resin to cure so as to form the fibre-reinforced polymer object.