New Parameters for Surface Evaluation: Tortuosity, Porosity and Correlation with Print Quality, 1990 International Printing & Graphic Arts Conference Proceedings
New porosimetry and permeability techniques to characterize paper structure have been used to determine the influence of BI-VIS pulps (produced by intermeshing/ co-rotating twin screw extruder) on surface properties.
Combining in plane air flow using the PARKER Print Surf fundamental equations with paper porosity using mercury porosimetry, yields the surface tortuosity. The BI-VIS papers have smaller mean pore depth and surface tortuosity than the reference papers (stonegroundwood SGW and Kraft pulps). This was mostly due to the replacement of coarser and stiffer fibres from SGW by more flexible, fibrillated and finer BI-VIS fibres.
An image analysis system (NACHET NS-1500) was used to evaluate print quality. The lower the edge raggedness, or the dot circularity, the higher the ratio of surface tortuosity to surface porosity.
New Parameters for Surface Evaluation: Tortuosity, Porosity and Correlation with Print Quality, 1990