Abstract: There is provided a method of producing a paper having a grammage according to ISO 536 of 50-250 g/m2, a Gurley value according to ISO 5636-5 of above 15 s and a stretchability according to ISO 1924-3 in the machine direction of at least 9%, said method comprising the steps of: a) providing a pulp, preferably sulphate pulp; b) subjecting the pulp to refining; c) diluting the pulp from step b) and adding the diluted pulp to a forming wire to obtain a paper web; d) pressing and the paper web from step c); e) drying the paper web from step d); f) compacting the paper web from step e) in a Clupak unit at a moisture content of 32-50%, preferably 37-49%, more preferably 41-49%; g) calendering the paper web from step f), optionally after drying, at a moisture content of 21-40%, preferably 30-40%, more preferably 32-39%; h) drying the paper web from step g).

Abstract: There is provided a method of making white sack paper having a grammage of 50-140 g/m2 and a Gurley porosity (ISO 5636/5) of 2-10 s, comprising the steps of: a) providing bleached pulp, such as bleached sulphate pulp; b) subjecting the pulp to high consistency (HC) refining and optionally low consistency (LC) refining to the extent that the sack paper obtains the Gurley porosity; c) adding cationic polymer, such as cationic starch, to the pulp in an amount of 1.5-5.0 kg/ton paper; and d) adding size to the pulp in an amount of 0.4-2.0 kg/ton paper; and e) forming the sack paper from the pulp, wherein less than 2 kg/ton paper of anionic starch is added to the pulp.

Abstract: There is provided a package material comprising an oxygen barrier polymer film, wherein the film comprises a polymer obtainable by a process comprising the steps of: a) oxidizing cellulose fibers to ultimately obtain cross-linked cellulose; and b) homogenizing the product of step a) to obtain fibrils in a width range of 1 nm to 150 nm. A corresponding use is also provided.

Abstract: There is provided a multilayered paper material for use in a valve sack for a hydraulic binder, comprising a paper layer, such as a Kraft paper layer, provided on at least one side with a pre-coating layer and a moisture barrier coating layer, wherein the pre-coating layer comprises inorganic filler and binder in a dry weight ratio of between 4:1 and 20:1.

Abstract: A paper laminate comprising a first stretchable paper layer, a second stretchable paper layer and an intermediate paper layer arranged between the first and the second stretchable paper layer, characterized in that the stretchability (ISO 1924/3) of the first and the second stretchable paper layer is at least 5% in both the machine direction (MD) and the cross direction (CD) and the stretchability (ISO 1924/3) of the intermediate paper layer is less than 4% in the MD and/or the CD.