Food product package formed by a sheet sealed on itself, method for manufacturing and filling such a packaging and blank

A method for manufacturing and filling at least one package for a food product, comprising at least the following steps:

• a step of providing a blank of a plurality of sheets secured to one another by a longitudinal edge, each sheet being intended to form a package each sheet having weakened portions comprising transverse weakened portions, and a tongue secured to a transverse edge of the sheet, the tongue having a free gripping end, the sheet having longitudinal tear guide strips, each opening at one end into a transverse edge of the sheet opposite the tongue and at another end into the free end of the tongue,
• a step of folding the blank or each sheet along the transverse weakened portions of each sheet to form a tube of rectangular cross-section and transversely sealing the blank to itself or each sheet to itself to form a peelable or tearable transverse joint, the tongue of each sheet projecting longitudinally from the transverse joint, wherein the sheet further has a transverse weakened portion along which the sheet is folded towards the outside of the package to form a sealing hem under the transverse joint, the tongue has an end bonded to a strip and a free end, the tongue and the strip are folded over the rear side of the package along a transverse weakened portion and the strip is sealed to the sealing hem by a “flesh-flesh” seal, the sealed strip forming the transverse joint of the package, the sealing hem allowing the sheet to be doubled in the sealing area of the transverse joint, and, for each sheet,
• a step of longitudinally sealing each sheet to form a longitudinal base joint thereby defining an inner cavity suitable for containing a food product,
• a step of filling the inner cavity with food product, and
• a step of closing the package by longitudinally sealing the sheet to itself to form a longitudinal top joint spaced from the longitudinal base joint.