Multi-channel and reversed airflow mouthpiece for an aerosol-generating article comprising activatable element

A method for assembling a mouthpiece, comprising the steps of:

• (a) providing an outer part, wherein the outer part forms a central inner channel and a tubular outer wall of the mouthpiece,
• (b) providing an inner part, wherein the inner part has a hollow cylindrical shape with a side wall, one open end and one closed end,
• (c) providing an activatable element,
• (d) assembling the outer part, the inner part and the activatable element, by inserting the activatable element into the inner part and inserting the inner part in an axial direction into the outer part such that the side wall of the inner part is located between the central channel and the outer wall of the outer part,
• wherein the mouthpiece further comprises
• an inlet end, configured to allow an aerosol to flow into the mouthpiece, and
• an outlet end, configured to allow the aerosol to flow out of the mouthpiece,
• wherein the aerosol flow path extends between the inlet and the outlet end,
• wherein the mouthpiece is formed such that the flow direction of the aerosol is reversed at least once between the inlet and the outlet end, and
• wherein the activatable element is held in position by being clamped within the mouthpiece.