Method for regulating basis weight of paper or board in a paper or board machine

A method for regulating basis weight of paper or board in a paper or board machine formed from a machine stock (MT) comprised of a plurality of component stocks (Mi), the method comprising the steps of:

• measuring a basis weight of the dry paper or board at the end of the paper machine;
• determining a stock target (Q0) of the machine stock (MT) based on the measured basis weight of the paper or board,
• determining desired stock proportions (KQi) of the component stocks (Mi) in the paper or board,
• determining a metering target (QiT) for each of the component stocks (Mi) based on the stock target (Q0) and the stock proportions (KQi), the metering target being the amount of the component stock per unit time flowing to form the machine stock,
• passing each of the component stocks (Mi) from a respective stock chest (20i) through a respective feed line (23i) to a mixing volume,
• measuring consistency (Csi) of each of the component stocks (Mi) in a respective one of the feed lines (23i) ,
• determining a flow target (FiT) for each of the component stocks (Mi) based on the measured consistency (Csi) of the component stock and the metering target (QiT) determined for the component stock, the flow target (FiT) being the volume of the component stock per unit time flowing to form the machine stock, and
• selectively regulating the flow of each of the component stocks (Mi) that is being fed to the mixing volume based on the flow target (FiT) determined for the component stock and thus regulating the flow of machine stock that is being fed to the headbox (150) from the mixing volume to thereby regulate the basis weight of the paper or board.