Artificial stone slab comprising veins and method of manufacturing same

A method of manufacturing an artificial stone slab comprising veins, said method comprising the following steps performed in the following order:

• a) preparing a moldable hardenable fluid mixture of a first material which includes stone particles having a different grain size distribution;
• b) pouring a controlled amount of said mixture of the first material into a mold including a peripheral frame of the size of the artificial stone slab to be manufactured, an upper face of the mixture deposited in the mold being exposed;
• c) engraving the exposed upper face of the fluid mixture with a predefined precise pattern of open branched grooves, coinciding with a pattern of branched thin veins to be obtained, displacing the fluid mixture of the first material within the mold;
• d) partially filling the branched grooves, impregnating at least inner faces of said branched grooves with a moldable hardenable fluid mixture of a second material, by projecting said fluid mixture of a second material through at least one projecting head, moving said projecting head following said open grooves while said projection takes place, by at least an automated arm moving and reproducing said predefined precise pattern of grooves to be obtained, the color of the first material and of the second material being different;
• e) displace the fluid mixture of the first material causing the collapse of the first material onto the second material and the closure of the grooves, obtaining a visible pattern of thin veins of a second material with a natural look;
• f) curing the first and second material, producing an artificial stone slab, by subjecting said first and second materials to vibration, compression, and vacuum until the fluid mixtures of the first material and of the second material are hardened;
• g) releasing the artificial stone slab from the mold.