at least two kinds of compounds being added

Full Title

Processes or apparatus for adding material to the pulp or to the paper (applying liquids or other fluent material to surfaces, in general B05; processes for making continuous lengths of paper D21F11/00) > characterised by the manner in which substances are added > Addition to the pulp; After-treatment of added substances in the pulp > Controlling the addition > by measuring pulp properties, e.g. zeta potential, pH > at least two kinds of compounds being added