An air-padded headbox is a piece of equipment that is designed to deliver a constant, uniform flow of stock to the Fourdrinier wire at the desired speed and location. The headbox has several design elements, including a perforated plate or tube bank and rotating rectifier rolls, that are designed to create and maintain turbulence to keep the fibers dispersed up to the slice opening. This is important because the design and operation of the headbox are critical to the quality of the sheet produced on the paper machine.