Add Filler
Add Filler adds spherical particles to coat the paper structure. Fillers are materials added during papermaking to influence the properties of the paper (e.g. dry strength, optical properties, surface smoothness and printability), or to reduce the production costs. Ground or precipitated calcium carbonate (GCC, PCC) is a commonly used filler. Other widely used fillers are china clay (kaolin), titanium dioxide, and talc.
Select Add Filler from the pull-down menu and click the Options’ Edit… button to select parameters for the addition of filler.
Filler Mode
With Add Filler, spherical particles are added to coat the complete structure currently in memory (Attached to Fiber) or a single material ID from the structure can be selected and replaced by the filler particles (Center in Material ID).
Attached to Fiber attaches the spherical particles to all objects present in the structure currently in memory. There is no choice of a specific Material ID to be coated. In other words, the whole structure is coated with the filler.
Center in Material ID replaces the selected material with spherical filler particles.
As an example of adding filler in the two modes, we use a structure with two types of synthetic fibers and added binder to observe the effect of adding filler particles as spheres of between 2µm and 10 µm diameter:
Stopping Criterion and Filler Material
As can be seen for Add Binder, a Stopping Criterion must be selected to end the addition of filler. The possible stopping criteria are Grammage and Solid Volume Percentage. For both available criteria define the amount of filler to be added below, either by its volume (Solid Volume Percentage / (%)) or by its weight (Grammage / (g/m²)).
For Grammage, the Filler Density [g/cm3] defines the specific density of the filler material in g/cm3. For some materials from the GeoDict Material Database, additionally a temperature must be entered.
When Manual or Undefined are selected as Filler Material, the density of the filler is not automatically taken from the GeoDict database, and you must enter it manually (Filler Density). If this filler material is regularly used, it can be saved in the material database. For further information, please consider the Material Database handbook.
For example, as the specific density of PCC is about 2.7-2.9 g/cm3 (2700-2900 kg/m3) enter the corresponding value for Filler Density in PaperGeo.
Filling Diameter
The Filling Diameter of the spherical particles can be set after clicking the Edit... button. The diameter of the particles can be constant or follow one of several distributions (Uniformly in interval, Gaussian, user-defined Probability Distribution, or Log-Normal).
Observe the filler particles when the diameter is set to a constant value of 5 and then, a constant value of 15.
