The filler materials that are used in paper mill can be classified into two groups. These are Inorganic fillers and organic fillers. The most common inorganic paper fillers used in paper mill are precipitated calcium carbonate (PCC), ground calcium carbonate (GCC), Kaolin clay, Talc and titanium dioxide ( TiO2). Other noticeable inorganic paper filler are Alumina trihydrate, precipitated silica and silicates (PSS) etc. Organic paper fillers are polymers (plastic pigments). They are hollow micro-spheres or porous filler.
In paper mill mostly used inorganic filler materials. But organic filler materials are used rarely; because of their high price. Organic paper filler used for special paper.
All paper filler are not suitable for all paper mills. It should be use basis on kind of pulp furnish, paper grade, process and paper machine configuration. Calcium carbonate (GCC or PCC) is not suitable for acid paper or wood-containing paper. It is suitable for wood-free or neutral-to-alkaline paper-making medium. Titanium dioxide is appropriate for special paper like offset but not talc.