The invention discloses a paperboard for packaging of a heat-sealable packaging material comprising: —a paperboard substrate comprising a first and a second side, —a first and an optional second dispersion coating layer on the first side, which first and optional second dispersion coating layer provides a barrier against at least one of liquid, moisture, grease and gas, —an extrusion coated barrier layer comprising a polyolefin, wherein the first and optional second dispersion coating layer is applied between the paperboard substrate and the extrusion coated barrier layer, and wherein the coat weight of the extrusion coated barrier layer is less than 15 gsm. The packaging material according of the invention minimizes the amount of plastic coating, but still provides the needed barrier properties for the packaging of food and/or liquid. The packaging material has especially been shown to provide a longer shelf life for food items packed in a packaging made from the material. Especially, the packaging material provides gas-, liquid and/or grease barrier properties. Although the packaging material comprises such low amount of extruded thermoplastic polymers, the material is readily heat-sealable.

The invention discloses a paperboard for packaging of a heat-sealable packaging material comprising: —a paperboard substrate comprising a first and a second side, —a first and an optional second dispersion coating layer on the first side, which first and optional second dispersion coating layer provides a barrier against at least one of liquid, moisture, grease and gas, —an extrusion coated barrier layer comprising a polyolefin, wherein the first and optional second dispersion coating layer is applied between the paperboard substrate and the extrusion coated barrier layer, and wherein the coat weight of the extrusion coated barrier layer is less than 15 gsm. The packaging material according of the invention minimizes the amount of plastic coating, but still provides the needed barrier properties for the packaging of food and/or liquid. The packaging material has especially been shown to provide a longer shelf life for food items packed in a packaging made from the material. Especially, the packaging material provides gas-, liquid and/or grease barrier properties. Although the packaging material comprises such low amount of extruded thermoplastic polymers, the material is readily heat-sealable.

A method of forming a fiber body includes defibrating a raw material in air to provide fibers; depositing the fibers in air onto a belt; applying pressure to the deposited fibers to form a pressurized web; and applying a liquid containing an additive to two surfaces of the pressurized web.

A method of forming a fiber body includes defibrating a raw material in air to provide fibers; depositing the fibers in air onto a belt; applying pressure to the deposited fibers to form a pressurized web; and applying a liquid containing an additive to two surfaces of the pressurized web.

A coated paperboard is disclosed which includes a printable coating containing substantially no fluorochemical or wax in which the coated paperboard is fully compostable as well as repulpable, and exhibits no tendency toward blocking. The coating may be a multiple layer coating.

A coated paperboard is disclosed which includes a base coat and top coat containing substantially no fluorochemical or wax, exhibiting good resistance to oil and grease, no tendency toward blocking, and being fully repulpable. Improved moisture resistance is also exhibited.

A coated paperboard is disclosed which includes a base coat and top coat containing substantially no fluorochemical or wax, exhibiting good resistance to oil and grease, no tendency toward blocking, and being fully repulpable. Improved moisture resistance is also exhibited.

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

A method for manufacturing a multi-layered paperboard is disclosed, which includes at least two fibrous layers, in which method at least one layer of the multi-layered paperboard is treated by applying an aqueous solution of a first strength component in dissolved form including anionic strength polymer and/or amphoteric strength polymer composition on a surface of layer, and an aqueous solution of a cationic second strength component in dissolved form is added to a fibre stock from which at least one of the fibrous layers joined together is formed.

A fiber body forming method includes a step of preparing a web which contains fibers and which has a bulk density of 0.09 g/cm.sup.3 or more; and a step of applying a liquid containing a binder which binds the fibers together to the web.