On-line control of a manufacturing process for a multicomponent sheet material

摘要

Controlling a process for the manufacture of a multicomponent sheet material 612. The control method comprises the steps of applying an acoustic or an electromagnetic signal to interact with the sheet material 612 whereby the interaction modifies the applied signal, detecting the modified signal, comparing the modified signal or data derived from it with data relating to the pre-determined parameter and modifying at least one step of the process whereby the data relating to the modified signal are modified towards the data relating to the pre­determined parameter. The sheet material 612 may be a laminate or a pre-impregnated fibre reinforced structure. The method may provide continuous in-line feedback control. A further method comprises correlating detected measurement signals with the results of a water pick-up method to calibrate the detected measurement signal results with one or more parameters of the sheet material. A prepreg and/or laminate material 612 may be formed by feeding a reinforcement material 602 through rollers 606 with a curable resin 604. Ultrasound transmitters 610 and receivers 608 may be positioned on opposite sides of the prepreg 612.