A new retention aid for the production of SC printing grades:: pilot paper machine results

A pilot paper machine trial has demonstrated the efficiency of a new dendrimeric retention aid in the production of supercalendered (SC-A) paper. The new additive was particularly effective in retaining fines and clay particles in the sheet. The first-pass retention increased by 6%, even at the addition rate of just 0.5 kg/metric ton. The highest gains in first-pass ash retention resulted in tests of the new additive with a flocculant. We found that the new retention additive did not impair sheet formation and that the sheet's physical properties were improved. We attributed the high efficiency of polymers at the low dosage rate to the high cationic charge available for charge neutralization of anionic dissolved and colloidal materials. Because of its high cationic charge, the dendrimer additive can significantly improve runnability in closed system applications.