Feasibility testing and development for non-destructive inspection of seals

• Main Author: Mohammed Imran
• Other Authors: Fan Zheng, David
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2021
• Subjects: Engineering::Mechanical engineering
• Online Access: https://hdl.handle.net/10356/150859
• Institution: Nanyang Technological University

An experiment was conducted to identify the ideal non-destructive testing method for retort type kraft paper packaging seals. The experiment was conducted on three different non-destructive testing methods which were, Pure Vacuum Decay Tester (Oxipack), Pressure Induced Deformation Measurement (PIDM) and the Capacitive Imaging (CI) method. The Oxipack test method utilised vacuum pressure to identify leakage in a package where a change in pressure would indicate a presence of leakage. The PIDM also utilised vacuum pressure to identify leakage in packages. However, instead of reading for a change in pressure, a change in height was observed to identify for presence of leakage. Lastly, the CI method utilised capacitance to identify defects in packages, where a change in capacitance would indicate a presence of defect. The Pure Vacuum Decay Test results was used as a baseline and to validate the results with the PIDM and CI method. The results were then analysed and compared to identify the ideal test method for identifying defects in kraft paper packaging seals. Large and small sized samples were chosen for the Oxipack and PIDM tests. A large sized sample was used for the CI test method. Air filled channel defects were created using tungsten wires. Defect sizes of 20 μm, 40 μm, 50 μm, 75 μm and 100 μm were created in the packages. Three readings were taken for each sample to increase accuracy of the results. The data from the results were then processed with the help of MATLAB and graphs were plotted for further analysis and comparison. After the analysis and comparison of the test results, it was concluded that the CI method was able to identify defect sizes of 50 μm, 75 μm and 100 μm. The CI method was also able to identify the location of defects present in the seal. The PIDM was able to detect defect sizes of above 40 μm for large sized samples and detect defect sizes of above 50 μm for small sized samples.