Method for producing a multi-cell component

1 . A method for producing a component comprising a plurality of complex hollow elements, each having a shape tapering gradually between a base and an apex, the complex hollow elements being connected to one another by one or more adjacent edges, the method comprising: filling, by a thermoplastic material, of a plurality of moulding cavities of a mould having a shape corresponding to the shape of the complex hollow elements of the component to be produced, the mould being held at a first temperature greater than the setting temperature of the thermoplastic material, then applying a holding pressure on the thermoplastic material while the mould is cooled until reaching a second temperature, wherein said holding pressure is applied during a compacting step by the mould and wherein the mould starts closing during the filling and finishes closing during the compacting step, interrupting the holding pressure on the thermoplastic material while the mould is cooled until reaching a third temperature, and removing a complex multielement component comprising a plurality of complex hollow elements from the mould.

2 . The production method according to claim 1 , wherein the mould comprises a first part which comprises the plurality of moulding cavities, and a second part located facing the first part, the filling of the moulding cavities by the thermoplastic material being carried out while the first part and the second part of the mould are spaced apart by an opening distance strictly greater than the value of the thickness of the multielement component to be produced, and the cooling from the second temperature to the third temperature being carried out while the first part and the second part of the mould are spaced apart by a distance corresponding to the thickness of the multielement component to be produced.

3 . The production method according to claim 1 , wherein the holding pressure on the thermoplastic material is between 50 bar and 2000 bar.

4 . The production method according to claim 1 , wherein the flow rate of thermoplastic material during filling is greater than a minimum flow rate corresponding to the ratio between the volume of thermoplastic material used and 80% of the degradation time of the thermoplastic material at the injection temperature chosen.

5 . The production method according to claim 1 , wherein the thermoplastic material is a polyetherimide, the first temperature being between 250° C. and 420° C., the second temperature being between 190° C. and 250° C. and the third temperature being less than 190° C.

6 . The production method according to claim 1 , wherein the thermoplastic material is a polyaryletherketone, the first temperature being between 320° C. and 420° C. and the third temperature being less than 300° C.

7 . The production method according to claim 1 , wherein the thickness of the walls of the complex elements produced is less than 0.5 mm.

8 . The production method according to claim 1 , wherein the length and the width of the complex multielement component produced are greater than 200 mm.

9 . A method for making an acoustic attenuation structure comprising:

producing a complex multielement acoustic component according to the method as defined in claim 1 ,

producing a complex multielement acoustic panel comprising the complex multielement acoustic component and a plurality of partitions forming acoustic cavities, each complex hollow element of the acoustic component being housed in an acoustic cavity so as to form an acoustic cell, and

assembling a face of the complex multielement acoustic panel with an assembly face of an acoustic skin.