PULP AND PAPER:what is the different between beaten and unbeaten fibers?
The cellulose plant fiber (pulp) is anionic; which means that it has a negative charge which increases from the pounding or beating of the fiber during pulp preparation in the hollander beater. Dry, unbeaten, fiber has very little or no charge. Pigment sticks to paper pulp through a ‘+’ and ‘-‘ attraction, a little like a magnet. As the fiber is beaten into a pulp, the ‘-‘ charge increases. Pigments have little attraction to the pulp, so a material which has a ‘+’ or positive charge must be added.
