High Frequency Acoustic Profiling for Multilayer Board Barrier Integrity
Inline high-frequency acoustic profiling measures micro-scale barrier delamination and polymer layer thickness across dynamic paperboard converting webs.
Time of Flight Diffraction
Inspection Technique
Non-destructive testing methods using ultrasonic waves identify internal flaws and cracks by measuring the travel time of signals diffracted from the tips of defects. In the context of heavy machinery maintenance for mills and converting plants, time of flight diffraction provides a way to inspect thick welds and structural components without halting production. Two transducers are placed on opposite sides of a weld to monitor for anomalies.
The system relies on the speed of sound through the material to pinpoint the exact location and size of an internal void.
Wave Analysis
Data captured during the scan appears as a cross-sectional view of the component, showing the depth and orientation of any irregularities. Using time of flight diffraction allows technicians to distinguish between harmless inclusions and dangerous stress cracks that could lead to equipment failure. The method is more accurate than traditional pulse-echo ultrasound for sizing vertical cracks.
Because it records the entire signal, the results can be reviewed and compared over time to track defect growth.
Detection Range
Surface roughness of the metal can interfere with the acoustic coupling and reduce the clarity of the signal. The technique requires highly trained operators to interpret the elaborate diffraction patterns correctly. It is less effective on materials with very high grain scattering or extremely thin sections.