A flexible barrier layer comprising microfibrillated dialdehyde cellulose

The present invention relates to a method for manufacturing at least one fibrous barrier layer wherein the method comprises the steps of:providing a first suspension comprising microfibrillated dialdehyde cellulose，providing a second suspension comprising microfibrillated cellulose and mixing said first suspension with said second suspension，adding polyvinylalcohol (PVOH) to said mixed first and second suspension and intermix to form a mixture，applying said mixture to a substrate to form a wet fibrous web， and drying said wet web on said substrate to form a fibrous barrier layer. The present invention also relates to a fibrous barrier layer comprising a mixture of microfibrillated cellulose， microfibrillated dialdehyde cellulose and PVOH.