Method for assembling tubular bodies made from a cardboard material with a sealing structure

A method for manufacturing a packaging comprising a tubular body made from one or more layers of a cardboard material and a sealing structure, the method comprising forming a security membrane, comprising:

• providing the sealing structure in the form of a flat membrane comprising:
• a central part with a shape conjugated to the shape of the opening of the tubular body, surrounded by a peripheral strip able to be folded down that is sufficient to suitably assemble the sealing structure with an inner lateral wall of the tubular body, and
• a tongue integral with the rest of the sealing structure, with a sufficient size to allow gripping by a consumer, comprising a proximal end situated in said peripheral strip and a distal end extending outside said peripheral strip, said tongue being folded down toward the central part of the sealing structure, on a face not designed for sealing, in order to form said flat membrane,
• inserting the sealing structure in a shaping tool and shaping it in the form of a basin, the peripheral strip becoming orthogonal to said central part,
• inserting and placing the tubular body at a predetermined level, and
• circumferentially sealing the peripheral strip in the tubular body using said shaping tool, with the exception of an unsealed part thereof, forming a marginal zone of the sealing structure in the packaging,
• wherein the proximal end of the tongue is situated in the unsealed part of the peripheral strip, and
• wherein the unsealed part of the peripheral strip extends over the circumference of the peripheral strip and over a certain width of the peripheral strip, creating a portion of the peripheral strip that does not contact the tubular body at the proximal end of the tongue,
• wherein the portion of the peripheral strip is located at the proximal end of the tongue and pulling on the tongue causes the top of the flat membrane to deform by distributing the pulling forces of the tongue over a surface of the sealed part of the membrane.