The Basic Aspect of Foil Arrangement

Abstract

During 30 years since the dewatering equipment was introduced onto paper machine, many attempts have been done on reinforcement of dewatering capacity. resulting the great improvement of sheet formation on wide range of paper machine. However, strange to say, there is no firm or definite opinion on the function of dewatering process. This might be because of few opportunity for investigating how each foil is concerned in the correlation between overrall dewatering activities and sheet forming process. The necessity of foil application at wet end should be in acordance with operating conditions of each paper machine though, there are many process of the arrangement based on the paper making conditions such as paper grade, basis weight, machine speed etc. which effect on wet sheet.Therefore it could be groped based on machine operaiting conditions and it would be hard to define the dewatering theory, for preference, the reasoning or conjecture from long experiences should be jointed in researrching factors related with the arrangement. Here is the summary introducing basic use of foil, essentials of sheet formation and foil arrangemet, and countermeasure for sheet forming based on our actual experience for 30 years.