An acrylamide-based polymer which contains one or more multiquaternized (multiquat) monomer unit(s) is provided. The acrylamide-based polymer can be used in a papermaking process to reduce pitch and stickies deposition, improve retention and drainage, and enhance dry strength properties of paper. Also included is a method of controlling pitch and stickies deposition in papermaking comprising treating pulp slurry with an acrylamide-based polymer which contains one or more multiquaternized (multiquat) monomer unit(s).

Provided is a method for producing paper that enables to fix an increased amount of starch components contained in papermaking process water to a papermaking raw material (suspended solid: SS) contained in the papermaking process water, and enables (1) enhancement of the strength of paper, (2) reduction in the contamination of the papermaking process water by microorganisms, etc., (3) suppression of the foaming of the papermaking process water, (4) decrease in the load of the waste water treatment, etc. The method comprises a step of adding a polymer having a polyalkylene oxide moiety to papermaking process water containing SS containing a papermaking raw material and unfixed starch. At this time, the concentration of SS contained in the papermaking process water is 100 mg/L or more, the concentration of the unfixed starch is 10 mg/L or more, and the salt viscosity of the polymer is 3 mPa.Math.s or more.

Provided is a method for producing paper that enables to fix an increased amount of starch components contained in papermaking process water to a papermaking raw material (suspended solid: SS) contained in the papermaking process water, and enables (1) enhancement of the strength of paper, (2) reduction in the contamination of the papermaking process water by microorganisms, etc., (3) suppression of the foaming of the papermaking process water, (4) decrease in the load of the waste water treatment, etc. The method comprises a step of adding a polymer having a polyalkylene oxide moiety to papermaking process water containing SS containing a papermaking raw material and unfixed starch. At this time, the concentration of SS contained in the papermaking process water is 100 mg/L or more, the concentration of the unfixed starch is 10 mg/L or more, and the salt viscosity of the polymer is 3 mPa.Math.s or more.

An acrylamide-based polymer which contains one or more multiquaternized (multiquat) monomer unit(s) is provided. The acrylamide-based polymer can be used in a papermaking process to reduce pitch and stickies deposition, improve retention and drainage, and enhance dry strength properties of paper. Also included is a method of controlling pitch and stickies deposition in papermaking comprising treating pulp slurry with an acrylamide-based polymer which contains one or more multiquaternized (multiquat) monomer unit(s).

The present invention pertains to the field of pulp or paper making. More specifically the present invention relates to a method of preventing a build-up of slime or removing slime from a surface contacted with water from a pulp or paper making process. The present invention can control slime in an efficient and environmentally friendly way.

The present invention pertains to the field of pulp or paper making. More specifically the present invention relates to a method of preventing a build-up of slime or removing slime from a surface contacted with water from a pulp or paper making process. The present invention can control slime in an efficient and environmentally friendly way.

A method for suppressing sedimentation of suspended substances is a method for suppressing sedimentation of suspended substances in water at the bottom of a tank disposed in a water system in papermaking equipment, comprising a step of blowing an oxygen-containing gas into the water, for stirring and aeration; a step of detecting a change with time in existence states of the suspended substances in the tank by the stirring and the aeration; and a control step of feeding at least one of an oxygen-containing gas and a slime control agent to the tank based on the detection result to suppress the sedimentation of the suspended substances in the tank.

A method for suppressing sedimentation of suspended substances is a method for suppressing sedimentation of suspended substances in water at the bottom of a tank disposed in a water system in papermaking equipment, comprising a step of blowing an oxygen-containing gas into the water, for stirring and aeration; a step of detecting a change with time in existence states of the suspended substances in the tank by the stirring and the aeration; and a control step of feeding at least one of an oxygen-containing gas and a slime control agent to the tank based on the detection result to suppress the sedimentation of the suspended substances in the tank.

The current method relates to compositions and methods for inhibiting the deposition of organic contaminants in pulp and papermaking systems. The current method also relates to controlling the deposition of organic contaminants on equipment in the pulp and papermaking systems, which can cause both quality and efficiency problems. In particular it relates to the use of non-sulfonated or slightly sulfonated lignin dispersions and solutions for inhibiting deposition of contaminants in pulp and paper making system.

A method for controlling paper making includes monitoring (302) a surface level of a fibrous suspension in a storage, and identifying (303) that the surface level has decreased so that at least one emptying criterion is met and thereafter identifying that the surface level has increased so that at least one refilling criterion is met, and responsively to the identifying that the surface level has increased so that the at least one refilling criterion is met, starting to dose a biocide agent into the fibrous suspension entering the storage. A corresponding apparatus and computer program are disclosed.