Continuous in-line non-destructive inspection of composite profiles

ADVISE-DETA has developed a novel system for the in situ, non-invasive and non-destructive inspection of composite profiles within the pultrusion line. The innovative elements of the PUL-NDI system concern the continuous scanning of the profiles by an array of ultrasonic sensors in a static or moving configuration and the intelligent algorithm for the real-time analysis of the scan data for the on-line detection of defects. This feature allows the tuning of the production systems at the pultrusion line for the elimination of defects in profiles, which are mainly caused by the poor fibre alignment or by the resin state in the bath or at the injection point.

The challenges which the PUL-NDI system has overcome relate to the movement of the profile as scanning takes place in the water tank. The profile enters the water tank and is prepared for the inspection before it arrives at the sensor placement area – bubbles and debris is removed from the composite material. The pultrusion line pullers keep the profile moving at a nominal constant line speed. The scanning is then performed across the surface of the profile in a repetitive action which ensures that every point of the structure is scanned at least once. The absolute elimination of ‘hidden (uninspected) zones’ in profiles is the major concern in the design of the sensors configuration of the PUL-NDI system.

The continuous operation of the inspection requires the sensor configuration to ‘scan’ the composite via a mechanical or electronic switching mode. The mechanical mode involves movement of the sensors across the profile dimensions while the electronic switching involves multiplexing of static sensor arrays extended along the profile cross section. The selection of the sensors configuration depends on the profile geometry and the pultrusion line speed.

Download PUL-NDI datasheet from the related files below