The present disclosure relates to a method of producing hydrophobic paper, using a sizing additive based on depolymerized lignin and a hydrophobic paper obtainable by such method.

The present disclosure relates to a method of producing hydrophobic paper, using a sizing additive based on depolymerized lignin and a hydrophobic paper obtainable by such method.

After cellulose fibers and cellulose ester fibers are co-refined, they are fed to a blend tank continuously feeds a wet laid process. The composition in the blend tank includes co-refined cellulose fibers and cellulose ester fibers and one or more additives, and the cellulose ester fibers have a denier per filament (DPF) of less than 3, a cut length of less than 6 mm, crimped, or non-round with a DPF of less than 3.

After cellulose fibers and cellulose ester fibers are co-refined, they are fed to a blend tank continuously feeds a wet laid process. The composition in the blend tank includes co-refined cellulose fibers and cellulose ester fibers and one or more additives, and the cellulose ester fibers have a denier per filament (DPF) of less than 3, a cut length of less than 6 mm, crimped, or non-round with a DPF of less than 3.

A hydrophobic coated paper substrate formed from a paper substrate of paper fibers and internal sizing agent, a surface size layer of one or more surface sizing starches, optionally one or more non-starch hydrophobic surface sizing agents, and optionally one or more paper pigments, on at least one surface of the paper substrate, and at least one hydrophobic pigmented coating layer of a paper pigment component and a hydrophobic pigment binder component on at least one surface size layer. Also a method for preparing such coated paper substrates.

A hydrophobic coated paper substrate formed from a paper substrate of paper fibers and internal sizing agent, a surface size layer of one or more surface sizing starches, optionally one or more non-starch hydrophobic surface sizing agents, and optionally one or more paper pigments, on at least one surface of the paper substrate, and at least one hydrophobic pigmented coating layer of a paper pigment component and a hydrophobic pigment binder component on at least one surface size layer. Also a method for preparing such coated paper substrates.

A method and apparatus for manufacturing medical paper for medical sterilization packaging, medical paper and medical sterilization packaging are disclosed. A paper web is formed of fibrous substrate comprising cellulosic fibers and optionally synthetic fibers, with opposite first and second sides. On-line with the forming of the paper web, reinforcing material is applied on the first side and pressed into structure of the paper web such that delamination resistance of the structure is increased. Sealing material is applied on the second side of the paper web on-line with the forming of the paper web.

A method for manufacturing paper or board is disclosed and further disclosed is an internal sizing system for providing improved retention of hydrophobic internal sizing agents. The internal sizing system includes a hydrophobic internal sizing agent as a first component selected from a group consisting of alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), rosin sizes and any combination thereof, and a water-soluble polymer product including amphoteric polyacrylamide as a second component, which amphoteric polyacrylamide has neutral or cationic net charge at pH 7, a weight-average molecular weight of 700,000-18,000,000 g/mol and a total ionicity of 4-28 mol-%, where the first component and the second component are provided as separate components or as a combination of the first component and the second component.

A method for manufacturing paper or board is disclosed and further disclosed is an internal sizing system for providing improved retention of hydrophobic internal sizing agents. The internal sizing system includes a hydrophobic internal sizing agent as a first component selected from a group consisting of alkenyl succinic anhydride (ASA), alkyl ketene dimer (AKD), rosin sizes and any combination thereof, and a water-soluble polymer product including amphoteric polyacrylamide as a second component, which amphoteric polyacrylamide has neutral or cationic net charge at pH 7, a weight-average molecular weight of 700,000-18,000,000 g/mol and a total ionicity of 4-28 mol-%, where the first component and the second component are provided as separate components or as a combination of the first component and the second component.

A starch composite for binding fibers includes starch particles which are first particles and second particles containing a hydrophobic material having an affinity for the starch particles, which are the first particles. The weight-average size of the second particles is less than the weight-average size of the first particles and the outer surfaces of the first particles are covered by the second particles.