An apparatus, system and method for emulsifying oil and water, such as for emulsifying a sizing agent for use in treating paper or paperboard, introduces a continuous phase under pressure through a continuous phase nozzle of a venturi apparatus and into a mixing section. A dispersed phase is introduced optionally under pressure into the mixing section of the venturi apparatus. The emulsion formed in the mixing section is directed through a mixed phase nozzle and out of the venturi apparatus. The mixed phase nozzle diameter of the venturi apparatus is larger than the continuous phase nozzle diameter at a ratio of greater than 1:1 and less than 4:1.

A method for preparation of a starch-promoted alkyl ketene dimer (AKD) sizing emulsion is provided. The inventive method comprises adding a sizing promoter comprising high-charge cationic starch and polyaluminum chloride (PAC) to a stabilized AKD emulsion and further wherein addition of said sizing promoter comprising high-charge cationic starch and PAC is effected at ambient temperature, after emulsification, stabilization, and homogenization of said stabilized AKD emulsion; and prior to addition of the starch-promoted AKD sizing emulsion to papermaking furnish, pulp, or fiber stock.

The present disclosure provides novel paper sheet mulch products having benefits over prior sheet mulches, which may include brown or recycled fibers, as well as additives, such as opacity, water-resistant, and strength additives, resulting in mulch products with an improved combination of basis weight, stretch, strength, opacity, and/or water-resistance characteristics.

The present invention provides multi-ply creped tissue products, and in particular embodiments creped wet-pressed tissue products, having substantially higher per-ply basis weights, such as from about 14.0 grams per square meter or greater. Despite having relatively high per-ply basis weights, the products are generally soft and flexible, such as having a softness value (measured as TS7) less than about 10.0 and a Stiffness Index less than about 20.0. While being soft and flexible, the tissue products are durable enough to withstand use, such as having a geometric mean tensile (GMT) greater than about 1,000 g/3″.

Disclosed is method for on-site glyoxylation of polyacrylamide in a paper or board mill, where a discontinuous batch glyoxylation reaction of aqueous reaction mixture is performed in reactor vessel having driven agitator to form aqueous polymer composition comprising glyoxylated polyacrylamide. The method comprises forming or obtaining the aqueous reaction mixture comprising polyacrylamide base polymer and glyoxal, determining alkali consumption of the mixture, and adding to the mixture, based on determined alkali consumption, pre-determined amount of alkali for adjusting pH to 8-10. The temperature is optionally adjusted to 15-40° C. and the on-site glyoxylation reaction of polyacrylamide base polymer is allowed to proceed. Viscosity of the mixture and/or a variable related to the viscosity is measured, acid is added to the mixture for lowering pH to <8, when a predetermined end viscosity value is attained, and the aqueous polymer composition comprising glyoxylated polyacrylamide is removed from the reaction vessel.

The invention relates to an aqueous polymer dispersion and its preparation. The dispersion comprises a styrene acrylate polymer, which is obtainable by free-radical polymerisation of 1-90 weight-% of monomer (a), which comprises at least one optionally substituted styrene; 10-99 weight-% of monomer (b), which comprises at least one alkyl (meth)acrylate, and 0-9 weight-% of monomer (c), which comprises at least one ethylenically unsaturated monomer, which is different from monomer (b). The polymerisation is conducted in a polymerisation medium comprising a cationic prepolymer, which is obtainable by free radical polymerisation of at least 10-55 weight-% of a monomer (i), which comprises at least one ethylenically unsaturated quaternary and/or tertiary amine, 35-90 weight-% of a monomer (ii), which comprises at least one optionally substituted styrene, and 0-55 weight-% of a monomer (iii), which comprises at least one alkyl (meth)acrylate. The oligomer content in the polymer dispersion is ≤1.4 weight-%, calculated from the dry polymer content.

A composition for sizing paper includes alkenylsuccinic anhydride (ASA) as the sizing agent and an emulsifier system of anionic emulsifiers and nonionic components, wherein the anionic emulsifiers are chosen from alkali metal salts of aliphatic carboxylic acids or aliphatic dicarboxylic acids and the nonionic components are chosen from polyethylene glycols.

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.

The invention relates to uncoated, fiber/starch composite materials manufactured without the use of fluorochemicals or additional binders that offer superior oil and grease resistance properties. Addition of an internal sizing agent in the preparation of the fiber/starch composite materials results in superior hot water and cold water resistance properties. The fiber/starch composite materials may be used for the manufacture of food service containers. The invention also relates to methods of preparation of the fiber/starch composite materials.

Treated substrates and methods of forming the same are provided. In an exemplary embodiment, a treated substrate includes lignocellulose and a polymer fixed to the lignocellulose to form the treated substrate. The polymer includes a succinic moiety that can reversibly change between a succinic anhydride and a succinic acid moiety. The treated substrate has a wet tensile index of about 3 newton meters per gram or less.