Method for manufacturing a sound-absorbing sandwich panel for reducing noise of an aircraft engine

A method for manufacturing a sound-absorbing panel with a sandwich structure and having a shape of portions of cylindrical surfaces, for reducing noise impact of an aeronautic engine, the method comprising the following steps in sequence:

• a) providing a first skin of a thermoplastic polymeric material;
• b) making a plurality of micro-holes through the first skin by mechanical punching of the first skin;
• c) having the first skin undergo a process of thermoforming on a mold;
• d) securing said first skin to a central layer by arranging a structural adhesive layer between the first skin and the central layer;
• and
• e) securing said central layer to a second skin by arranging a structural adhesive layer between the central layer and the second skin;
• wherein at least two adjacent components among the first skin, the central layer, and the second skin comprise uncured polymerizable material;
• and
• wherein step d) and/or step e) further comprises the step of:
• f) having the first skin, the central layer, and the second skin undergo a curing process in autoclave with vacuum bag, according to a specific pressure and temperature cycle, for co-curing the uncured components.