An on-line control and reaction process for pH adjustment and a control device for automatically adjusting pH value are provided. The process includes mixing a first enhancer and a second enhancer, optionally after diluting the first enhancer and/or the second enhancer with water, to form a mixture, setting a base pH value (δ1) and a target pH value (δ2), and adding pH adjuster into the mixture via a pH control unit and mixing to obtain a product with the target pH value. The pH control unit adjusts the adding of the pH adjuster by measuring or inputting certain parameters.

A multi-ply through air dried structured tissue having a bulk softness of less than 10 TS7 and a lint value of 5.0 or less. Each ply of the tissue has a first exterior layer that includes a wet end temporary wet strength additive in an amount of approximately 0.25 kg/ton and a wet end dry strength additive in an amount of approximately 0.25 kg/ton, an interior layer that includes a first wet end additive comprising an ionic surfactant, and a second wet end additive comprising a non-ionic surfactant, and a second exterior layer.

A process for flocculating filler particles in water is provided. The process comprises adding a flocculant to a mixture comprising filler particles and water, wherein the flocculant has a reduced specific viscosity (“RSV”) of from about 5 dL/g to about 16 dL/g, a viscosity average molecular weight of from about 1,200,000 to about 7,500,000, and a cationic charge of from about 5 mol % to about 50 mol %. Flocs formed by flocculation of the filler particles and the flocculant have a median particle size of from about 10 um to about 150 um. The filler is not precipitated calcium carbonate alone. The flocs provided by the process are useful in increasing ash content of a paper product.

Methods of reducing paper dusting in a papermaking process, and a low dusting tissue having increased strength are provided. Application of a polymer comprising at least one amine-containing vinylic or allylic monomer to at least one surface of a paper web during the papermaking process reduces the dusting tendency of the paper, and inpcreases both the wet and dry strength of the paper product.

A multi-ply through air dried structured tissue having a bulk softness of less than 10 TS7 and a lint value of 5.0 or less. Each ply of the tissue has a first exterior layer that includes a wet end temporary wet strength additive in an amount of approximately 0.25 kg/ton and a wet end dry strength additive in an amount of approximately 0.25 kg/ton, an interior layer that includes a first wet end additive comprising an ionic surfactant, and a second wet end additive comprising a non-ionic surfactant, and a second exterior layer.

A method for manufacturing paper is disclosed. A pulp slurry is produced, a paper sheet is formed from the slurry, an aldehyde functionalized polymer or polymers in combination with at least one additional strength additive is added to the slurry before and/or after sheet formation, and a water soluble acid is added on the paper sheet.

In a method for preparing glyoxylated polyacrylamide, in which an aqueous solution of polyacrylamide is supplemented with ethanediol (glyoxal) under stirring by means of a circulation pump, the reaction is started by the addition of a base, at a basic pH value above 8, and is allowed to react under stirring and/or circulating, whereupon the reaction is stopped by the addition of an acid under stirring and/or circulating after completion of a predetermined reaction time, wherein the method is performed as a discontinuous method in which the quantitative reaction of ethanediol with an excess amount of polyacrylamide in an aqueous basic medium is controlled and/or regulated by at least one, of the following factors:

a) turbidity measurement
b) pH adaptation as a function of the temperature
c) pH adaptation as a function of the reaction time
d) drop of pH the value, or
e) current consumption of the circulation pump.

The disclosure relates to methods and compositions for enhancing the performance of a sizing agent in a papermaking process using a sizing agent enhancer. The sizing agent can be emulsified with an emulsifier and the sizing enhancer can be a polymer comprising at least one primary or secondary amine containing monomer. The method can comprise emulsifying the sizing agent with the emulsifier; and thereafter adding the emulsified sizing agent and the sizing enhancer, separately from or contemporaneously with the emulsified sizing agent, to a fiber furnish of a papermaking process. The combination of the emulsified sizing agent and the sizing enhancer improves the sizing of product paper over the use of the sizing agent without the sizing enhancer. In at least some embodiments, the emulsified sizing agent is ASA emulsified with a polymer comprising at least one primary or secondary amine containing monomer and the sizing enhancer comprises a diallylamine-acrylamide copolymer.

Provided is a method of making paper and paperboard. In particular graft copolymers of vinyl monomers and functionalized vinylamine-containing base polymers by Michael addition are added to a paper furnish. The composition can be used alone or in combination with other additives for use in paper making and to improve paper making processes such as paper dry and wet strength properties.

The present invention relates to methods for preparing an aqueous acrylamide solution having a low acrylic acid concentration. In addition, the present invention relates to methods for reducing the acrylic acid concentration of an aqueous acrylamide solution. The methods involve a bioconversion of acrylonitrile to acrylamide in the presence of a biocatalyst, wherein during the bioconversion the content of acrylonitrile is maintained at 0.3 w/w % or more referred to the total weight of the composition in the reactor. Also provided is an aqueous acrylamide solution which is obtained by the methods of the present invention. Furthermore, the present invention is related to an acrylamide homopolymer or copolymer obtained by polymerizing the acrylamide of the aqueous solution.