Headbox and forming station for fiber-reinforced cementitious panel production

A continuous process for using a slurry feed apparatus comprising:

• a headbox mounted transverse to the direction of travel of the moving web, having a transverse back wall, sidewalls, a concave transverse front wall, an open top, and an open bottom for directing slurry onto the forming web;
• a moveable dam releasably attached to the back wall, a seal attached to a bottom wall of the dam;
• headbox mounts extending from opposed said sidewalls
• a vibration unit for vibrating slurry discharged from the headbox, wherein the vibration unit is a single mass system comprising a vibration table having spring loaded legs and two motors which direct forces directly into the deposited mat of fiber-cement slurry and cancel out vibration forces in other directions, the vibration unit is placed under the headbox and extends beyond the head box
• wherein the vibration table is mounted on a vibration base,
• wherein the spring constant of the springs of the spring loaded legs ranges between 50 to 500 lbs/inch;
• wherein the motors are selected such that they are capable of delivering sufficient force to the table to provide a stroke in the range of +/− 1/64 inch to +/−¼ inch;
• for depositing a uniform layer of a cementitious slurry containing reinforcing fibers from the headbox onto a moving forming web, the process comprising:
• depositing the cementitious slurry containing reinforcing fibers on the inside surface of the headbox,
• depositing the slurry from the headbox as a continuous layer on to the travelling web;
• and
• vibrating the deposited cementitious slurry containing reinforcing fibers on the moving forming web with the vibration unit.