3. Additives

Once refined, the paste is stored at 3-4% concentration in a mixing vat, where various auxiliary products are added before final purification and dilution.

The role of these additives is either to improve certain physical and optical properties of the paper (fillers, colorants and sizing products), or to optimize manufacturing stages (retention products, various additives). A distinction is made between :

• charges in the mass ;

• bonding products ;

• retention agents ;

• various additives ;

• dyes and fluorescent agents.