An In-Line, Contactless and Non-Destructive Method and System for Detecting Defects in a Moving Cardboard Structure

An in-line and contactless system for detecting and identifying defects in a moving laminated cardboard tube made of layers of spirally wound paper plies, the system comprising:

• a signal generator coupled to an emitter probe, the emitter probe positioned at a first location, at a predetermined distance from the moving laminated cardboard tube, the emitter probe being operable to emit acoustic waves at predetermined frequencies toward the moving laminated cardboard tube;
• the acoustic waves being converted into mechanical waves propagating through the moving laminated cardboard tube;
• a receiver probe positioned at a second position, at a predetermined distance from the moving laminated cardboard tube and spaced away from the first location, the receiver probe being operable to capture acoustic waves resulting from a conversion of the propagated mechanical waves through the moving laminated cardboard tube;
• and
• a signal processing device operatively connected to the receiver probe, the signal processing device being configured to analyze propagation properties of the captured acoustic waves captured by the receiver probe, and programmed to detect and identify defects in the moving laminated cardboard tube based on predetermined properties measured in the captured acoustic waves.