List of Chemicals used in Papermaking
Optical brightening agent
– Paper that is derived from both natural or synthetic fiber pulp is not completely naturally white, so manufacturers often add agents that increase its
fluorescence. This is done for majority of paper used today.
– Coloring of paper is common, and it is done to all papers that have their specific purpose (wrapping paper for example). Most common pigments are violet
– Paper mix is has not only fibers, but also a lot of filler material that sometimes does not want to bind to the fibers. For that purpose, retention
agents need to be introduced to the recipe. Most commonly used retention agents are calcium carbonate, polyethyleneimine and polyacrylamide.
– Used to increase pH State of the pulping mix. Higher pH mix enables creation of the smoother fibers, which is useful before its cutting to smaller
– Added to the paper recipe to enabler paper to not to size in the presence of water. Before introduction of these agents into paper production, paper was
very sensitive to the water
Wet strength additive
– Chemicals such as epichlorohydrin, melamine, urea formaldehyde and polyimines had to be added to the paper to enable it to retain strength when it’s wet.
Dry strength additive
– Cationic starch and polyacrylamide (PAM) derivatives are added to give general strength to the paper in non-wet conditions (compression strength, tensile
breaking strength, bursting strength, delamination resistance and more).
– They enhance internal structure of the paper, most commonly used substances are calcium carbonate and china clay.
– Added to provide paper with the surface that will increase water retention, and thus make paper more durable. Most commonly used agents are dextrin,
oxidized starch, styrene butadiene latex, and styrene acrylic.
– They are used in three kinds of processes for creation of chemical pulp from wood chips (Kraft process, Sulfite process and Soda pulping).
– Sodium dithionite, Ozone, hlorine dioxide and Hydrogen peroxide.