Paper Microstructure and Electrophotography

Finacial support provided by NSERC under Grant G201274

 

The figure above shows the surface microstructure of simulated paper. The virtual paper surface above is generated using a new 3D fibre network model of paper strcuture. The model incorporates the effects of fibre deposition, random fibre orientations, fibre mechanical properties and most importantly, paper consolidation. The aim of the model is to compute virtual paper structures for a new Xerographic simulation platform that investigates the role of paper structure heterogeneity in electrostatic transfer. Details about the model and its applications have appeared in the Journal of Pulp and Paper Science (JPPS). For more Click here: text and Figures

Using digitized images of SEM images of a commercial paper cross sections have been used as input to a new FEM electrostatic transfer model, we can characterize dielectric heterogeneity in paper (thickness, mass and composition variations) on several length scales, identifying those that are most relevant for creating visible toner transfer variations during image production in Xerography (i.e. print mottle). The figure above shows an SEM cross section of a commercial paper (bottom part of figure). The top part of the figure shows how the corresponding electrostatic fields are shaped by the paper during electrostatic transfer of toner to paper. The white deposits in the paper are PCC fillers. This work will appear in the Journal of Modelling and Simulations in Materials Science and Engineering (2004). Click here for a copy:

This methodology has recenlty been coupled directly with our computational paper strcuture model to directly predict the response that various "virtual" paper strcutres will have on the electrostatic stransfer forces in Xerography. The mathematical characterization of how trensfer field respond to important paper structures has appeard reenly in the Journal of Modelling and Simulations in Materials Science and Engineering (2006). Click here for a copy.

The data below shows a portion of simulated paper exposed to an applied electric field, such as those that are produced during electrophotographic image production (e.g. inside a Xerox machine when a copy is made). There are three views of the paper, the dielectric map of the papr, the y-direction electric field and the x-direction electric field, The y-direction force is mainly responsible for toner detachment and image reporouction onto paper. Click here to vew the electrostatic fields within the toner transfer gap (i.e. the region between which the paper is inserted to transfer toner to paper). The hetergeneous effect of paper on making the electric field non-uniform is evident.