Effect of Shape and Application Process of Precipitated Calcium Carbonate on Optical and Mechanical Properties of Recycled Paper

Recycled paper was made with Precipitated Calcium Carbonate (PCC) which is famous for alkaline mineral filler. Filling behavior, whiteness, opacity and mechanical property change according to shape of PCC. Calcite PCC was difficult to disperse and to be filled uniformly because calcite PCC hardly aggregated but it could improve tensile strength as its amount increases. A suitable filler to be filled in recycled paper was needle-like aragonite and it could increase folding resistance slightly when aragonite of 10 wt% against dried pulp mass was added. PCC already synthesized was not effective on improvement of optical property but a new process, In-situ process, developed whiteness and opacity because PCC nucleated on fiber surface and then diffused reflection happens on surface. Whiteness of recycled paper made by In-situ process was 64 which is 92% of standard presented by Korea Public Procurement Service.