D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
D21H23/00—Processes or apparatus for adding material to the pulp or to the paper
D21H23/02—Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
D21H23/22—Addition to the formed paper
D21H23/24—Addition to the formed paper during paper manufacture
D21H23/26—Addition to the formed paper during paper manufacture by selecting point of addition or moisture content of the paper
D21H23/28—Addition before the dryer section, e.g. at the wet end or press section
D—TEXTILES; PAPER
D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
D21H5/00—Special paper or cardboard not otherwise provided for
D21H5/0005—Processes or apparatus specially adapted for applying liquids or other fluent materials to finished paper or board, e.g. impregnating, coating