Capillary Pressure Dynamics and Coating Micro Porosity Structure in Paper
Micro-porous paper coating capillary dimensions govern dynamic ink vehicle filtration rates, ink setting speeds, press energy consumption, and total converted sheet yield.
X-Ray Micro-Tomography
Imaging Technique
Non destructive three dimensional visualization of the internal structure of paper or board allows for the inspection of fibre networks and coating layers without cutting the sample. Using x-ray micro-tomography provides high resolution digital slices that reveal how individual components are distributed through the thickness of the sheet. This method exposes the voids, filler particles and the interface between the substrate and the ink.
It captures the complex geometry of the porous network which governs how liquids penetrate the material. Practitioners use these scans to debug coating defects that are invisible to the naked eye.
Material Analysis
Digital reconstruction of the sample allows researchers to measure the tortuosity and connectivity of the pores. In the study of paperboard, x-ray micro-tomography identifies the exact location of internal delamination or the compression of the bulk after a creasing operation. These insights help mills optimize the density of the middle ply to maintain stiffness.
Scanning Boundary
The size of the specimen is limited by the power of the source and the resolution of the detector. Small samples provide the best clarity for viewing individual fibres, while larger samples show broader structural trends. X-ray micro-tomography requires significant processing power to handle the large data sets generated during the rotation of the object.