Described herein is a water vapor barrier coating composition that is especially useful for paper-based packaging applications. The composition includes a basecoat layer and a topcoat layer that are applied to fibrous substrates in sequential order as aqueous coatings. The basecoat layer is applied and dried and then the topcoat layer is applied and dried. The basecoat layer includes an aqueous solution of ethylenically modified polyvinyl alcohol and optionally a plasticizer. The topcoat layer includes an aqueous polymeric dispersion or emulsion, compatibilized with the base layer by adding a small percentage of ethylenically modified polyvinyl alcohol solution, and optionally a viscosity modifier, defoamer, release agent, slip agent, crosslinker, and/or anti-blocking additive. The composition includes a synergistic interaction between the basecoat and the topcoat. The composition is optionally biodegradable and/or compostable, along with a coated paper stock, without the need to separate and reprocess the coating.

Described herein is a water vapor barrier coating composition that is especially useful for paper-based packaging applications. The composition includes a basecoat layer and a topcoat layer that are applied to fibrous substrates in sequential order as aqueous coatings. The basecoat layer is applied and dried and then the topcoat layer is applied and dried. The basecoat layer includes an aqueous solution of ethylenically modified polyvinyl alcohol and optionally a plasticizer. The topcoat layer includes an aqueous polymeric dispersion or emulsion, compatibilized with the base layer by adding a small percentage of ethylenically modified polyvinyl alcohol solution, and optionally a viscosity modifier, defoamer, release agent, slip agent, crosslinker, and/or anti-blocking additive. The composition includes a synergistic interaction between the basecoat and the topcoat. The composition is optionally biodegradable and/or compostable, along with a coated paper stock, without the need to separate and reprocess the coating.

The invention refers to a method to produce a packaging material comprising the steps of; treating at least one surface of a paperboard substrate with a binder and with a metal salt, printing at least a part of said treated surface with ink, and applying at least one polymer layer on said printed surface. The packaging material produced in accordance with the invention shows good printability and simultaneously good adhesion of the applied polymer layer.

The invention refers to a method to produce a packaging material comprising the steps of; treating at least one surface of a paperboard substrate with a binder and with a metal salt, printing at least a part of said treated surface with ink, and applying at least one polymer layer on said printed surface. The packaging material produced in accordance with the invention shows good printability and simultaneously good adhesion of the applied polymer layer.

The present invention relates to process for the production of a coated substrate comprising cellulosic fibres, the process comprising the steps of: i) providing a first substrate comprising cellulosic fibres and having a dry content of less than 50%; ii) applying a coating composition to the first substrate in an amount of more than 5 g/m.sup.2, calculated as dry weight of the coating composition, wherein the coating composition comprises: microfibrillated cellulose (MFC), and optionally a water retention agent selected from carboxymethyl cellulose (CMC), anionic polyacrylamide (A-PAM), sodium polyacrylates, polyacrylic acid derivatives, guar gum, alginate, MFC prepared from carboxymethylated fibers, MFC prepared from oxidized fibers, MFC prepared by CMC-functionalised fibers, and/or combinations thereof; and iii) mechanically dewatering the first substrate.

The present process provides an energy efficient coating process which can be performed online.

The present invention relates to process for the production of a coated substrate comprising cellulosic fibres, the process comprising the steps of: i) providing a first substrate comprising cellulosic fibres and having a dry content of less than 50%; ii) applying a coating composition to the first substrate in an amount of more than 5 g/m.sup.2, calculated as dry weight of the coating composition, wherein the coating composition comprises: microfibrillated cellulose (MFC), and optionally a water retention agent selected from carboxymethyl cellulose (CMC), anionic polyacrylamide (A-PAM), sodium polyacrylates, polyacrylic acid derivatives, guar gum, alginate, MFC prepared from carboxymethylated fibers, MFC prepared from oxidized fibers, MFC prepared by CMC-functionalised fibers, and/or combinations thereof; and iii) mechanically dewatering the first substrate.

The present process provides an energy efficient coating process which can be performed online.

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 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.

The present invention relates to a press-heating gas grafting hydrophobization apparatus, and a hot water-resistant paper and an oil-absorbing paper manufactured using the press-heating gas grafting hydrophobization apparatus. In the press-heating gas grafting hydrophobization apparatus according to the present invention, since a non-air-permeable dryer belt is provided surrounding and pressing a drying roller to prevent dissipation from a base material of a fatty acid chloride vaporized by the drying roller, the press-heating gas grafting hydrophobization apparatus has an advantage of improving efficiency of a gas grafting reaction. Therefore, by using the press-heating gas grafting hydrophobization apparatus according to the present invention, the reaction amount of fatty acid chloride per unit area can be remarkably improved.

The present invention relates to a press-heating gas grafting hydrophobization apparatus, and a hot water-resistant paper and an oil-absorbing paper manufactured using the press-heating gas grafting hydrophobization apparatus. In the press-heating gas grafting hydrophobization apparatus according to the present invention, since a non-air-permeable dryer belt is provided surrounding and pressing a drying roller to prevent dissipation from a base material of a fatty acid chloride vaporized by the drying roller, the press-heating gas grafting hydrophobization apparatus has an advantage of improving efficiency of a gas grafting reaction. Therefore, by using the press-heating gas grafting hydrophobization apparatus according to the present invention, the reaction amount of fatty acid chloride per unit area can be remarkably improved.