Chemicals used in the paper industry

Chemicals used in paper production are employed to enhance the paper’sappearance, strength, printability, and durability.These chemicals are typically used in the stages of pulp preparation, papermaking, and surface treatments.

Below arethe most commonly used chemicals in the paper industryand their purposes:

1.Fillers

They provide the paper withopacity,smoothness, andbrightness.

• Calcium carbonate (CaCO₃):The most common filler. Used in acidic or alkaline environments.

• Kaolin (China Clay):Provides opacity and surface smoothness.

• Talc(Talcum):Enhances smoothness and print quality.

2.Binders

They ensure fibers adhere to each other and increase strength.

• Starch:The most common natural binder. Increases wet or dry strength.

• Latex(SBR, PVA):Used as a surface binder in coated papers.

3.Dyes and Pigments

Used to give color to the paper.

• Organic and inorganic pigments(blue, yellow, green, red, etc.)

• Optical brightening agents (OBA):Makes the paper appear whiter and brighter.

4.Retention Aids

They improve the retention of chemicals and fillers onto the fibers.

• Polyacrylamide (PAM)

• Polyethyleneimine (PEI)

• Cationic starch

5.Wet Strength Agents

Prevents the paper from disintegrating when wet.

• Polyamine resins (PAE)

• Melamine-formaldehyde resins

6.Dry Strength Agents

Increases the paper’s resistance properties such as tear and break strength when dry.

• Oxidized starch

• CMC(Carboxymethyl cellulose)

• Acrylic polymers

7.Sizing Agents (Water Resistance Chemicals)

Reduces the paper’s absorption of liquids like water and ink, improving printability.

• AKD (Alkyl Ketene Dimer)

• ASA (Alkenyl Succinic Anhydride)

• Rosin size

8.pH Adjusters and Other Auxiliary Chemicals

• Caustic soda(NaOH):pH raiser

• Aluminum sulfate(Alum):Used as a coagulant or for sizing in acidic environments

• Biocides and antifungals:Prevents microorganism growth

• Defoamer:Reduces foam generated during production

• Dispersant:Regulates particle distribution