This paper describes on-line feedback control techniques for regulating the area density distribution in low-density air-laid nonwoven webs in both the machine direction and the cross-machine direction. The web area density is monitored in real-time by a scanned-laser-based device. The web density distribution along the machine direction is regulated by controlling the transporting belt while the web density distribution in the cross-machine direction is regulated by a vane system in the suction chamber.
展开▼