The fabric has a layer of PP foil, which is characterized by its impermeability and prevents the penetration of the inner contents of the bag to the outside, as well as the passage of air humidity and water from the surrounding environment into the bag. Impermeability is required mainly for powdered materials (cocoa, carbon black, ...), where there is a risk of dusting the filling from the bag onto its surface.
Fabrics can be:
- one-sided coated - the lamination is applied on one side of the fabric, i.e. on the one that is standardly inside the bag
- double-sided coated - lamination is applied on both sides of the fabric