Abstract: A method for production of a hollow body by extrusion and blowing of a thermoplastic resin, includes the steps of filling a quantity of resin into an accumulator (1) which has an accumulation chamber (12) with an open end, placing a blowing mould (24) with an internal cavity (36) and a constricting section (37) in communication with the open end, axially displacing a core (10, 11) across the constriction point of the internal cavity such as to cover a projecting part of the core with a layer of resin (38), continuing the axial displacement of the core in the internal cavity (36) to axially extend the layer of resin (38) and applying a fluid pressure to the internal surface of the resin layer through the core to obtain a hollow body.

Abstract: A fire extinguisher (61) with a reservoir made from a plastic material (60), for containing an extinguishing agent and a discharge device (65), fixed to a neck (64) of the reservoir, for controlling a discharge of the extinguishing agent. The discharge device has an outlet nozzle (70) and a plunge tube (69), arranged within the reservoir (60), such as to conduct the extinguishing agent from a base section (71) of the reservoir, opposite the neck, to the outlet nozzle, characterised in that a wall (62) of the reservoir has an internal rib (3) with a helical form, the coil axis of which (A) is essentially parallel to the plunge tube (69).