Abstract
The purpose of this study was to examine the effect of external fibrillation of chemical pulp fibers on the retention of filler during sheet forming in a high-vacuum dewatering device. An ultra-fine friction grinder was used to prepare fibers with different degrees of external fibrillation, while keeping their internal fibrillation constant.
The entrapment of filler particles was found to increase with increased internal fibrillation of fibers in the presence of chemical aid, and it can be further increased by promoting mostly external fibrillation of fibers. Increasing the degree of external fibrillation alone, without changing the internal fibrillation, can be used as means to control the retention of filler.
