New findings of entrained air and dissolved gases in PM wet end : Mill case study

In a mill case study with three different paper machines producing different paper grades, entrained air and dissolved gases were studied. In addition to entrained air, dissolved gas is an important component. The balance between the two states rapidly changes in different locations of the process depending on the type of equipment and chemicals, e.g. headbox can have a big influence on the final entrained air volume on former. Defoamer chemical changes the balance from entrained air to dissolved gases. By understanding the air and gas behaviour in the process, it is possible to bring the operation of the paper making process and final paper quality to optimum level.