Creating New Surface Sized and Film Coated Paper Grades, 1998 Metered Size Press Forum II Proceedings

Film press technology not only creates new opportunities for new paper grades, but also has great potential for reducing production costs. Consequently, the use of film-type size presses has widened from the application of surface sizing of fine papers to include surface sizing of woodcontaining paper grades and line paper specialties, as well as high speed pigmenting and coating of woodfree and woodcontaining grades. To fulfill the requirements of these new applications, totally new coating concepts, metering elements and applicator roll cover materials have been developed. The two film press concepts discussed in this paper are the results of this development process. The issue of choosing one or two coating stations depends on the machine speed, as well as the type of products and basis weight range desired. In the SymSizer concept both sides of paper are treated simultaneously in one coating station (referred to as Metered Size Press/C2S or MSP/C2S). With the SymCoat concept the paper is coated one side at a time in two separate coating stations (Metered Size Press/ClS+ClS or MSP/2ClS). In pilot scale coating, the MSP/C2S has successfully performed up to 1500 rn/min and MSP/2ClS up to 2000 rn/min without runnability problems.