Abstract: The invention relates to a plant (10) for blowing a pressure medium in a blank (12), which comprises a mould (12) which is used for receiving the blank (12) and comprises a top wall (24) trough which the neck (16) of the blank (12) is projected, a nozzle (22) which comprises a pressure medium lower output orifice (34) and is provided with an ring sealing joint (40) arranged under the lower circumference (44) of said output orifice (34) in such a way that the circumference (44) of the output orifice (34) surrounds the neck (16) of the blank (12). Said invention is characterised in that the sealing joint (40) is provided with a lower elastic annular lip (48) in such a way that the pressure medium rests on the top face (54) of said lip (48) for pressing the free annular lower edge (58) thereof against a supporting wall (18, 24), thereby ensuring the tightness of the nozzle (22).

Abstract: The invention relates to a method for assembling a composite box, in two parts, the method being implemented by a machine having: a conveyor system for bringing an envelope into position; a store for storing the blanks of the trays; means in the form of extractor arms for removing one of the tray blanks from the store and bringing it to the assembly station, facing the envelope; a device for gluing the edges of the envelope and the tongues of the tray blank during the movement towards the assembly station; a framework having two mobile carriages, a first carriage carrying a die for shaping the blank, and a second carriage carrying a tappet for driving the envelope towards the die and a stamp maintaining a counter-pressure using a suitable device against the pressing device of the die.