A method of reducing contaminants in a pulp or papermaking process includes the steps of: providing a lignocellulosic pulp comprising lignocellulosic fibers and at least one hydrophobic contaminant; providing a cationic polymer; providing a cleaning blend comprising a vegetable oil alkyl ester and at least one surfactant; and applying the cationic polymer and the cleaning blend to the lignocellulosic pulp to reduce a content of the at least one hydrophobic contaminant in the pulp or papermaking process.

A method for suppressing sedimentation of suspended substances ef the present invention 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.

Disclosed is a method for controlling a biofilm removing a formed biofilm and/or controlling a growth of microorganisms, preferably bacteria, in an aqueous environment of an industrial manufacturing process including a cellulosic fibre material. A compound according to Formula I is administered to the aqueous environment, in which Formula I R1, R2 and R3 independently represent a hydrogen atom; halogen atom; hydroxy group; amino group; alkylamino group, alkyl group, hydroxyalkyl group, haloalkyl group or alkoxy group having 1 to 4 carbon atoms; or an acylamido group having 1 to 10 carbon atoms; and A represents 2-thiazolamine; 2-propenenitrile; 2-propenoic acid; alkyl ester or hydroxyalkyl ester of 2-propenoic acid having 1 to 4 carbon atoms; or —CHCHCONR5R6 group, where R5 and R6 represent independently hydrogen atom, alkyl or hydroxyalkyl having 1 to 4 carbon atoms, with the proviso that the compound according to Formula I is not 3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or 4-amino-N-2-thiazolyl-benzenesulphonamide.

A method for controlling the deposition of stickies in pulping and papermaking processes comprises adding to fibre pulp or stock an additive comprising an organo-modified siloxane comprising units of the formula: [R.sup.1.sub.aZ.sub.bSiO.sub.(4-a-b)/2].sub.n in which each R.sup.1 is independently selected from a hydrogen atom, an alkyl, aryl, alkenyl, aralkyl, alkaryl, alkoxy, alkanoyloxy, hydroxyl, ester or ether group, and each Z is independently selected from an alkyl group substituted with an amine, amide, carboxyl, ester, or epoxy group, or preferably at least one or more groups —R.sup.2—(OC.sub.pH.sub.2p).sub.q(OC.sub.rH.sub.2r).sub.S—R.sup.3; wherein n is an integer greater than 1; a and b are independently 0, 1, 2 or 3; R.sup.2 is an alkylene group or a direct bond; R.sup.3 is a group as defined for R.sup.1 or Z above; p and r are independently an integer from 1 to 6; q and s are independently 0 or an integer such that 1≦q+s≦400; and wherein each molecule of the organo-modified siloxane contains at least one group Z. The organo-modified siloxane is preferably a hydroxyl- or alkyl-endcapped linear polydimethylsiloxane, in which 5 to 18 mole percent of silicon atoms are substituted by Z groups of the formula —R.sup.2—(OC.sub.pH.sub.2p).sub.q(OC.sub.rH.sub.2r).sub.s—R.sup.3, in which p is 2, r is 3 and q and s are independently 10 to 20, R.sup.2 is an alkylene group having from 1 to 6 carbon atoms or a direct bond, and R.sup.3 is a hydrogen atom or a hydroxyl, alkoxy, ester or ether group.

Disclosed is a method for controlling a biofilm, removing a formed biofilm and/or controlling a growth of microorganisms, preferably bacteria, in an aqueous environment of an industrial manufacturing process including a cellulosic fibre material. A compound according to Formula I is administered to the aqueous environment, in which Formula I R1, R2 and R3 independently represent a hydrogen atom; halogen atom; hydroxy group; amino group; alkylamino group, alkyl group, hydroxyalkyl group, haloalkyl group or alkoxy group having 1 to 4 carbon atoms; or an acylamido group having 1 to 10 carbon atoms; and A represents 2-thiazolamine;

2-propenenitrile; 2-propenoic acid; alkyl ester or hydroxyalkyl ester of 2-propenoic acid having 1 to 4 carbon atoms; or —CHCHCONR5R6 group, where R5 and R6 represent independently hydrogen atom, alkyl or hydroxyalkyl having 1 to 4 carbon atoms, with the proviso that the compound according to Formula I is not 3-[(4-methylphenyl)sulphonyl]-2-propenenitrile or 4-amino-N-2-thiazolyl-benzene-sulphonamide.

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2,500,000-18,000,000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

The invention relates to a use of a water-soluble polymer product comprising amphoteric polyacrylamide, which has neutral or cationic net charge at pH 7, a weight-average molecular weight of 2 500 000-18 000 000 g/mol and a total ionicity of 4-28 mol-%. The polymer product is used for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres. The invention relates also to a method for controlling deposit formation caused by hydrophobic substances in manufacture of paper or board, where a fibre web is formed from an aqueous suspension of fibres, as well as to produced paper or board.

A pulp-digester screen cleaner having a pneumatic actuator with a cylinder and a rod coaxially disposed within the cylinder. An actuator mounting plate is used to mount the actuator outside of a pulp-digester screen housing pipe. A rod seal has a body disposed on the pipe that prevents any loss of fluid or pressure, yet allows the rod to pass into the pipe. The cylinder contains all of the mechanics of the pneumatic actuator and can be easily serviced without draining the digester. The rod is disposed through a first aperture of each of a pair of scrapers. A treated edge of each of the pair of scrapers varies to match different digester screen types and patterns. The present pulp-digester screen cleaner eliminates the need for chemical cleaning or other mechanical cleaning solutions. It will also improve pulp quality, increase pulp production, and promote overall digester efficiency.

The disclosure provides methods and compositions for reducing the viscosity of black liquor. Also provided are methods of inhibiting deposition of scale and methods of processing black liquor. In some embodiments, the compositions include a carboxylate-containing polymer and an inorganic salt. In some embodiments, the compositions include a carboxylate-containing polymer, an inorganic salt, and a surfactant.

A method is disclosed for predicting the microbial status of a paper or board making process and/or quality of the dry board or paper obtained from the process for controlling microbial status of a paper or board making process or quality of the dry board or paper obtained from the process. Surface level and duration of time in at least one storage tower or pulper are monitored and correlated with respective predetermined values for the tower or pulper in order to predict the risk of microbial activity.