Pulp and Paper Research Institute of Canada

Anthony M Scallan

Steven R Middleton

Derek H Page

Xuejun Zou

Thomas J Fox

Jos&eacute;e Desmeules

Harold V Green

A method is described for attaining high levels of loading of calcium carbonate fillers in the lumens of wood pulp fibers. The pulp is pretreated with a cationic polymer prior to being impregnated with the filler. Different conditions of pH and temperature are specified depending on whether the filler is a precipitated calcium carbonate or a ground calcium carbonate. The lumen-loaded pulps are used to make novel products with advantages in higher filler retention and sheet strength over conventionally made papers.

Method for producing pulp and paper with calcium carbonate filler

Acidic papers, books, and other sheets of cellulosic material may be deacidified and so given a prolonged life by bringing the papers, books, or other sheets of cellulosic material to be treated in intimate contact with a source of solid alkali such as calcium carbonate filled paper, at an elevated humidity and under mechanical pressure for a period long enough to produce deacidification; the process differs from other processes in that it is carried out in the solid state without the use of liquid or gaseous reactants.

Method for the deacidification of papers and books

Paper of improved properties is produced from pulp in which filler is selectively loaded within the fiber lumens by agitating a suspension of pulp and filler until the fiber lumens become loaded with filler, separating the residual suspended filler from the loaded fibers and vigorously washing the pulp until substantially all of the filler on the external surfaces of the fibers is removed.

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Pointe Claire, Canada

Anthony M Scallan