Method for making a thin-walled acoustic component

A method for making an acoustic component comprising a plurality of hollow complex acoustic elements each having a shape tapering gradually between a base and an apex, the hollow complex acoustic elements being connected to one another by one or more adjacent edges, the method comprising:

• heating a film of thermoplastic material to a first temperature above a glass transition temperature or melting temperature of said film,
• shaping the heated film of thermoplastic material in a tool comprising a mould which has a plurality of mould cavities having a shape corresponding to the shape of the hollow complex acoustic elements of the acoustic component to be made, the heated film of thermoplastic material being shaped locally in each of the mould cavities, at least the mould being kept at a second temperature above the glass transition temperature or melting temperature of the thermoplastic material and below the first temperature,
• cooling the mould to a third temperature below the glass transition temperature or melting temperature of the thermoplastic material, and
• removing a complex acoustic multi-element panel comprising said plurality of hollow complex acoustic elements from the mould,
• wherein the film of thermoplastic material has a plurality of portions of excess thickness at determined locations on the film, said locations corresponding to the locations of the mould cavities of the mould.