Process for coating a preformed substrate

A process for coating a preformed substrate, the process comprising:

• providing a semi-finished product comprising said preformed substrate, a coating layer, and an adhesive layer interposed between said preformed substrate and said coating layer;
• providing a mould comprising a first and a second half-mould each having a respective conformation surface, wherein the first half-mould comprises a main body and an elastically deformable membrane which at least partially forms the conformation surface of the first half-mould, and wherein at least the conformation surface of the second half-mould is substantially counter-shaped to said preformed substrate;
• arranging said semi-finished product on the conformation surface of said second half-mould with said preformed substrate proximal to said second half-mould;
• putting under depression a fluid acting on a first face of said membrane opposite to said second half-mould by applying a depression to the fluid such that the pressure acting on the first face of the membrane and atmospheric pressure acting on an opposite face of the membrane are substantially equal to each other or such that the atmospheric pressure acting on the opposite face of the membrane is slight predominant with respect to the pressure acting on the first face of the membrane, to maintain said membrane in a first configuration in which it is adherent to said main body;
• with said semi-finished product interposed between said conformation surfaces and said membrane in said first configuration, closing said mould while maintaining a free distance between said conformation surface of said first half-mould and said semi-finished product along a whole surface extension of said semi-finished product;
• subsequently, pressurizing said fluid to arrange said membrane in a second configuration in which it is elastically expanded towards said second half-mould for compressing said semi-finished product between said membrane and said second half-mould;
• maintaining said membrane in said second configuration, heating said semi-finished product for firmly fixing said preformed substrate and said coating layer to each other;
• and
• wherein the fluid is a liquid.