Container for loose materials and related blank

A container for loose materials made by folding a blank made of flexible material, comprising:

• containment walls defining inside the container an internal space adapted for receiving the loose material, wherein the containment walls delimit at least partially a dispensing opening adapted for dispensing the loose material;
• a concertina folding spout, hinged to the containment walls at a hinge defined by a line of weakness of the blank at the dispensing opening and configured to pass, in use, from a retracted position, where the concertina folding spout is folded on itself and defines a cover for closing the dispensing opening, to an extracted position, where the concertina folding spout is extended, placing the internal space in communication with the outside atmosphere through the dispensing opening and providing a chute for pouring out the loose material, and vice versa;
• reversible locking means, located between the containment walls and the concertina folding spout and configured to reversibly fix the concertina folding spout in the retracted position to the containment walls;
• and
• sealing means located between the containment walls and the concertina folding spout and configured to fix the concertina folding spout in the retracted position to the containment walls until the container is opened for the first time, after which the sealing means permanently change their configuration from the closed configuration to an open configuration which is visible to a user.