Method For Making Paper and Cardboard With High Dry Strength and Resulting Papers and Cardboards
AssigneeS.P.C.M. SA
InventorsRene Hund, Christian Jehn-Rendu, Fabrice Moretton
Life of this patent
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Abstract
A method for making a sheet of paper and/or cardboard and the like, comprises, prior to forming said sheet, adding to the fibrous suspension, separately or mixed, in any sequence of introduction, into one or more injection points, at least three dry strength agents respectively: first agent corresponding to a (co)polymer having a cationic filler density higher than 1 meq/g and exhibiting primary amine functions; a second agent corresponding to a synthetic organic (co)polymer having cationic filler density higher than 0.1 meq/g; and a third agent corresponding to a (co)polymer having an anionic filler density higher than 0.1 meq/g.
Claims25
Method for fabricating a sheet of paper and/or cardboard and the like, comprising, before formation of the sheet from a fibrous suspension, adding to the fibrous suspension, separately or mixed, in any order of introduction, at one or more injection points, at least three dry strength agents respectively:
- a first agent corresponding to a (co)polymer having a cationic filler density higher than 1 meq/g and having primary amine functions,
- a second agent corresponding to a synthetic organic (co)polymer having a cationic filler density higher than 0.1 meq/g,
- and a third agent corresponding to a (co)polymer having an anionic filler density higher than 0.1 meq/g.
Dependencies are inferred from the claim text.