A laminating unit to manufacture a multi-layer composite (2) in a laminating machine (1), comprising a laminating rotating roll (16), laminating a first web (3) onto a second web (4), is characterized in that it further comprises: driving means (42), rotating (R) the roll (16); gripping means (39, 41), maintaining the first web (3) in contact with the roll (16); first detection means (43, 46) emitting first detection signals (44, 47) in accordance with detected longitudinal positions of the first web (3); second detection means (48, 51) emitting second detection signals (49, 52) in accordance with detected longitudinal positions of the second web (4); and control means (53), regulating a rotation speed of the driving means (42) and of the roll (16) as a function of the first and second signals (44, 47, 49, 52), to convey, correct longitudinally positions of the first web (3), and laminate the first web (3) in register onto the second web (4).