A bonding system (62, 136) for bonding a web comprising at least a pair of web layers (64A, 64B), the bonding system (62, 136) comprising: a velocity changing device for increasing and decreasing a velocity of the web in a machine direction; an anvil (76A, 76B, 138A, 138B) and a corresponding ultrasonic horn (78A, 78B) that interact to form ultrasonic bonds on the web; an anvil actuator (80A, 80B) configured to control a movement of the anvil (76A, 76B, 138A, 138B); and a control system for controlling operation of the anvil actuator (80A, 80B) and the velocity changing device, the control system programmed to: operate the velocity changing device to decrease a moving velocity of the web from a feed velocity to a bonding velocity as the web passes between the anvil (76A, 76B, 138A, 138B) and the ultrasonic horn (78A, 78B); and control movement of the anvil (76A, 76B, 138A, 138B), via operation of the anvil actuator (80A, 80B), to synchronize the movement of the anvil (76A, 76B, 138A, 138B) with the moving velocity of the web; wherein interaction between the anvil (76A, 76B, 138A, 138B) and the ultrasonic horn (78A, 78B) forms bonds having a bond length in the machine direction, and wherein the control system is programmed to control a velocity mismatch between the movement of the anvil (76A, 76B, 138A, 138B) and the bonding velocity of the web, so as to selectively control a dwell time of the anvil (76A, 76B, 138A, 138B) on the web and thereby control the bond length of the bonds. a velocity changing device for increasing and decreasing a velocity of the web in a machine direction; an anvil (76A, 76B, 138A, 138B) and a corresponding ultrasonic horn (78A, 78B) that interact to form ultrasonic bonds on the web; an anvil actuator (80A, 80B) configured to control a movement of the anvil (76A, 76B, 138A, 138B); and a control system for controlling operation of the anvil actuator (80A, 80B) and the velocity changing device, the control system programmed to: operate the velocity changing device to decrease a moving velocity of the web from a feed velocity to a bonding velocity as the web passes between the anvil (76A, 76B, 138A, 138B) and the ultrasonic horn (78A, 78B); and control movement of the anvil (76A, 76B, 138A, 138B), via operation of the anvil actuator (80A, 80B), to synchronize the movement of the anvil (76A, 76B, 138A, 138B) with the moving velocity of the web; operate the velocity changing device to decrease a moving velocity of the web from a feed velocity to a bonding velocity as the web passes between the anvil (76A, 76B, 138A, 138B) and the ultrasonic horn (78A, 78B); and control movement of the anvil (76A, 76B, 138A, 138B), via operation of the anvil actuator (80A, 80B), to synchronize the movement of the anvil (76A, 76B, 138A, 138B) with the moving velocity of the web; wherein interaction between the anvil (76A, 76B, 138A, 138B) and the ultrasonic horn (78A, 78B) forms bonds having a bond length in the machine direction, and wherein the control system is programmed to control a velocity mismatch between the movement of the anvil (76A, 76B, 138A, 138B) and the bonding velocity of the web, so as to selectively control a dwell time of the anvil (76A, 76B, 138A, 138B) on the web and thereby control the bond length of the bonds.