Abstract: The invention concerns a manufacturing process for producing hermetic single-use food containers, including: forming a container body (30) having an peripheral rim (31), placing the container body in a sealing head having a first die (2) and a second die (8) having cooperating annular sealing surfaces (4, 10) facing the rim (31), sealing a closing lid (34) placed over the container body with the rim (31) by applying the first die (2) and the second die (8) one against the other. According to the invention, the first die (2) is provided with a continuous annular rib (6) in its sealing surface (4), the rib having a height (h) which is at least equal to a maximum depth of wrinkles that might appear on the rim upon forming the container body, whereby a sealing groove (12) is formed by the rib (6) in a side of the rim during the sealing.