Process and apparatus for building tyres

An apparatus for building a tyre, comprising:

• at least one forming support;
• and
• at least one forming device to form components of elastomeric material on the at least one forming support, wherein the at least one forming device comprises:
• at least one extruder to deliver a continuous elongated element of elastomeric material at a linear delivery speed;
• at least one conveyor for the continuous elongated element having a moving surface along a predetermined direction at a linear advancing speed different from the linear delivery speed and toward a proximal end of the at least one conveyor adjacent the at least one forming support;
• at least one application device for distributing the continuous elongated element having a desired cross section into coils on the at least one forming support, wherein the at least one application device is positioned close to the proximal end of the at least one conveyor;
• and
• at least one device, wherein the at least one device rotates the at least one forming support on an axis thereof relative to the proximal end of the at least one conveyor at a peripheral speed,
• a control unit;
• wherein the at least one extruder faces the at least one conveyor without interposition of other devices upstream of the at least one conveyor so that the extruder feeds the continuous elongated element directly between a moving surface of a conveyor belt and a presser device within the at least one conveyor, wherein the conveyor belt is wrapped on a distal roller located at a distal end of the at least one conveyor and the distal roller is adjacent the at least one extruder thereby eliminating calendaring;
• wherein the control unit is programmed to drive the at least one extruder, the at least one conveyor, and the at least one forming support to:
• maintain the peripheral speed to be different from the linear delivery speed, so as to deform the continuous elongated element;
• modify, during an application cycle, the linear advancing speed and subsequently modify the peripheral speed thereby creating two distinct steps of varying a ratio between the peripheral speed and the linear delivery speed and a ratio between the linear advancing speed and the linear delivery speed to obtain the desired cross section without calendaring.