Process for manufacturing paper or cardboard
AssigneeS.P.C.M. SA
InventorsCyril BARRIERE, Rémi OLIVIER, René HUND
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Abstract
This invention relates to a method for manufacturing a sheet of paper or cardboard, according to which, before forming said sheet, at least one N-vinylformamide polymer that is partially hydrolyzed in the form of an inverse emulsion is added, at one or more injection points, to a fibrous suspension in the presence of an anti-gelling agent, and having a cationic regain between 30 and 150%, the inverse emulsion having a weight ratio of partially hydrolyzed N-vinylformamide polymer to anti-gelling agent in the range between 1,000,000/5000 and 1,000,000/50,000.
Claims20
A process for manufacturing a sheet of paper or cardboard, said process comprising, before said sheet is formed, adding at least one N-vinylformamide polymer, partially hydrolyzed in the form of an inverse emulsion in the presence of an anti-gelling agent, and having a cationic regain of between 30 and 150%, is to a fibrous suspension at one or more injection points, the inverse emulsion having a partially hydrolyzed N-vinylformamide polymer/anti-gelling agent weight ratio of between 1,000,000/5,000 and 1,000,000/50,000.
Dependencies are inferred from the claim text.