Pilot-scale trials on slow and fast Fourdrinier paper machines have shown that a sheet can be filled with clay and calcium carbonate by passing a concentrated filler suspension through a wet sheet. The suspension was supplied from a secondary headbox located at the dryline. The trials showed that no damage to the sheet occurs when the filler suspension is applied to the wet sheet. At low filler concentrations, an uneven distribution of filler in the sheet was observed in the z direction, but at high filler levels, the unevenness in filler distribution decreased. The strength of the paper decreased with increasing filler concentration, as is the case in conventionally filled paper. Aside from fillers, other chemicals can be retained by this process as well. Polyethylene imine (PEI) showed an increase in the dry strength of paper on the slow Fourdrinier machine, but not on the fast one. The main advantage of this method is that the filling process can be completely separated from the wet-end chemistry.
|Number of pages||7|
|Journal||Industrial and Engineering Chemistry Research|
|Publication status||Published - 28 Apr 2004|