Innovative design of moulds by additive manufacturing for sustainable processing of expanded polymers

This present work explores how the Additive Manufacturing (AM) technique can be leveraged to create innovative moulds for expanded polymers (EPs). Traditional steam-chest moulding tools, typically made from cast aluminium alloys due to their high thermal diffusivity and good castability, can be replaced with lighter moulds. These new moulds are precisely designed and produced using laser-powder bed fusion technology, resulting in significantly reduced thermal capacity and optimised steam distribution throughout the part volume. The general design approach is outlined, and the performance of this innovative solution is demonstrated through a case study. Experimental tests on the prototype moulds and moulding equipment revealed substantial reductions in cycle times and energy consumption compared to traditional steam-chest moulding methods for producing the same product. The tests also demonstrate that the evolution of the moulds influences the machines currently used in the process. These could be revisited and redesigned to improve further the performance provided by the new AM moulds even more.