Ultrasonic Systems for Liquid Absorption Measurement

摘要

Experiments were carried out on coated paper with simulation of surface non-uniformity by the printed pattern withrndifference in ink density. The printed areas of different ink density were in the form of 3 mm stripes. Simulatedrndifference in ink coverage ranged from 100% to zero in the amount of ink coverage (with 80, 60, 40, 20, 10, 4, 2 andrn1% in between) and was printed with laser ink. Printed areas represented at the same time the different surfacernstructure and chemistry. The surface difference was tested with liquid on dynamic penetration tester with ultrasonicrnsensor consisted with 32 micro sensors (1 mm2 each). The results obtained for Non-uniformity Index by ultrasonicrnmethod showed very good correlation with the difference in ink density measured by image analysis. Ultrasonicrnsensor was able to recognize the difference in non-uniformity of liquid penetration into coated and printed paperrnsurface down to very small ink density difference which equals “1” on visual rating scale (no mottle).rnApplication: This study shows that Penetration Evenness Analyzer is a reliable tester which can be used for QC asrnwell as for troubleshooting and new product development. Non – uniformity of liquid phase penetration into paperrnfrom coating color may results in streaks and form the ink into coated or uncoated paper may cause the print mottle.