Abstract: The installation contains means (1) for continuous production of a paste made of a thermoplastic material, means (8) for accumulating and temporarily storing the paste thus produced and means (15) for taking the paste out of the accumulating means and storage means and introducing it into a first mould comprising thermoregulated means in the form of a syringe. The invention is characterised in that the output of the accumulating means and storage means comprises a distributor (12) that has at least two outputs (13, 14) and can be controlled in order to deliver the paste to one of the two outputs, whereby one of said outputs (13) is adapted in order to be coupled to thermoregulated means (15) in the form of a syringe and the other output (14) is adapted in order to be permanently connected to the charging orifice of a piston (17) that injects the paste at a high pressure into a second part-forming mold (17), whereby one output thereof (19) is adapted in order to be permanently coupled to the second mold.