The invention relates to a process (100) for manufacturing an object (1) made of thermoplastic polymer composite from at least two parts (10) made of thermoplastic polymer composite, said thermoplastic polymer composite comprising a fibrous reinforcement and a thermoplastic polymer matrix, said process comprising the steps of:
arranging (120) the two parts (10) made of thermoplastic polymer composite adjacently or overlapping at an assembly interface zone (11), and
heating (130) to melt the thermoplastic polymer matrix at said assembly interface zone (11), so as to form an object (1) made of thermoplastic polymer composite comprising a welded interface (12).