Processes or apparatus for adding material to the pulp or to the paper

DTEXTILES PAPER D21Papermaking D21HPULP 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

D21H23/00Processes or apparatus for adding material to the pulp or to the paper

D21H23/02characterised by the manner in which substances are added D21H23/04Addition to the pulp After-treatment of added substances in the pulp D21H23/06Controlling the addition D21H23/08by measuring pulp properties D21H23/10at least two kinds of compounds being added D21H23/12by measuring properties of the formed web D21H23/14by selecting point of addition or time of contact between components D21H23/16Addition before or during pulp beating or refining D21H23/18Addition at a location where shear forces are avoided before sheet-forming D21H23/20Apparatus therefor D21H23/22Addition to the formed paper D21H23/24during paper manufacture D21H23/26by selecting point of addition or moisture content of the paper D21H23/28Addition before the dryer section D21H23/30Pretreatment of the paper D21H23/32by contacting paper with an excess of material D21H23/34Knife or blade type coaters D21H23/36Knife or blade forming part of the fluid reservoir D21H23/38the fluid material being applied with a special device D21H23/40only one side of the paper being in contact with the material D21H23/42Paper being at least partly surrounded by the material on both sides D21H23/44Treatment with a gas or vapour D21H23/46Pouring or allowing the fluid to flow in a continuous stream on to the surface, the entire stream being carried away by the paper D21H23/48Curtain coaters D21H23/50Spraying or projecting D21H23/52by contacting paper with a device carrying the material D21H23/54Rubbing devices D21H23/56Rolls D21H23/58Details thereof D21H23/60the material on the applicator roll being subjected to a particular treatment before applying to the paper D21H23/62Reverse roll coating D21H23/64the material being non-fluent at the moment of transfer D21H23/66Treating discontinuous paper D21H23/68whereby the paper moves continuously D21H23/70Multistep processes Apparatus for adding one or several substances in portions or in various ways to the paper, not covered by another single group of this main group D21H23/72Plural serial stages only D21H23/74Apparatus permitting switching from one technique to another D21H23/76characterised by choice of auxiliary compounds which are added separately from at least one other compound D21H23/765Addition of all compounds to the pulp D21H23/78Controlling or regulating not limited to any particular process or apparatus