Additives for increased retention and pitch control in paper manufacture
AssigneePulp and Paper Research Institute of Canada
InventorsRobert H. Pelton, Lawrence H. Allen, Henry M. Nugent
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Abstract
A process is disclosed for the production of paper and paper-like products which consists of the addition to the papermaking furnish of kraft lignin or modified kraft lignin and poly(oxyethylene).
Claims15
In a papermaking process utilizing an aqueous wood pulp slurry, the improvement which effects increasing the retention of fines, fillers and pigments while at the same time decreasing the deposition of pitch on the papermaking apparatus which improvement comprises:
- adding to the slurry an effective amount of a poly(oxyethylene) having a molecular weight of 10.sup.5 or greater and a kraft lignin product wherein the poly(oxyethylene) is added to the slurry at a rate of between 0.002 and 0.5 percent by weight and the kraft lignin product is added at a rate of between 0.01 and 12 percent by weight both rates being based on the weight of oven-dried pulp.
A method of increasing fines retention and decreasing pitch deposition on a papermaking machine in a papermaking process, said method comprising the steps of initially adding to an aqueous wood pulp slurry an effective amount of an aqueous kraft lignin product solution wherein the kraft lignin product has a relatively high molecular weight and a relatively low degree of sulfonation and subsequently adding to the slurry an effective amount of an aqueous solution of poly(oxyethylene) having a molecular weight of 10.sup.5 or greater, wherein the kraft lignin product is added at a rate of between 0.01 and 12 percent by weight and the poly(oxyethylene) is added at a rate of between 0.002 and 0.5 percent by weight, both rates being based on the weight of oven-dried pulp.
Dependencies are inferred from the claim text.