Composite packaging material sheet, method for forming a composite packaging material sheet, composite package and method for forming a composite package

Composite packaging material sheet for the formation of a composite package filled with a pourable product comprising at least:

• a packaging material sheet base comprising a multilayer packaging material having a designated opening;
• and
• an opening device applied on the packaging material sheet base and about the designated opening and designed to seal the designated opening and being controllable in an open position so as to free at least a portion of the designated opening;
• wherein the packaging material sheet base comprises at least a first face and a second face opposite to the first face;
• wherein the second face is designed to define an inner surface of the composite package to be formed from the composite packaging material sheet;
• wherein the packaging material sheet base comprises a plurality of crease lines delimiting a plurality of panels;
• wherein the opening device comprises a base frame for coupling the opening device to the packaging material sheet base and about the designated opening;
• wherein the base frame comprises at least a first flange connected to the second face and having a rectilinear peripheral portion;
• wherein the rectilinear peripheral portion is adjacent and parallel to one respective crease line defining a reference crease line.