Method for the on-line control of the opacity of a paper sheet

摘要

A method of on-line control of opacity of moving sheet material being produced by a paper making machine includes an opacity control loop where an opacity additive is controlled and a basis weight control loop where the stock input to a headbox is controlled. These two control loops are decoupled by means of an opacity to stock feed forward and a basis weight to titanium dioxide feed forward. In addition, the effect of moisture change is decoupled from opacity.