Abstract: The present invention relates to methods for manufacturing paper or paperboard with improved strength, the methods comprising the addition of the reaction product of a cationic polyacrylamide and an aqueous aldehyde generating compound or a glyoxal releasing compound, or glyoxal itself, prepared at the mill site at high concentrations, then diluted and added into a fiber furnish prior to forming or drying of the paper or paperboard sheet.
Abstract: In sizing paper and paperboard with an aqueous ASA sizing system, a dispersal is formed comprising an ASA, a water-immiscible carrier, and a cationic water-soluble dispersing agent and when desired, a non-ionic surfactant. The dispersal can be shipped and stored for a prolonged time until use. The dispersal is added to water to form an oil-in-water sizing emulsion. This prepared emulsion is suitable for sizing paper and paperboard directly without the need for additional emulsifying agents or expensive equipment.
Abstract: Phospholipids such as lecithins provide improved rheological properties for coating a rapidly moving web, such as a paper web. The phospholipids are preferably applied to the paper web as part of a coating mixture, and they can be included in the coating mixture by first including the phospholipid in a lubricant additive mixture that includes an emulsifier, a fatty acid vehicle, and plasticizer. The lubricant is well-suited for short-dwell coating methods.