Development of Metered Size Press Coating for High-Speed Operations, 2000 Metered Size Press Forum

The recent announcements of new high-speed film coating capacity in Europe have cuased a lot of interest in the MSP coating technology. The key to this development is not only improved technical solutions, but also a better understanding of the process and the mechanisms involved. Understanding of the MSP process is crucial, but even more important is the understanding and control of the papermaking process from sheet formation until the final calendering. Especially for this coating process, it is desirable to design a base sheet to resist and excessive coating penetration and then achieve a desired surface coverage. The coating process itself is also subjected to a lot of discussion regarding its quality potential and high-speed runnability restrictions. Furthermore, the choice of layout, e.g. C2S or 2C1S, for high-speed coating is alos subjected to some discussion since C2S is now introduced even at high machine speeds. This paper will deal with critical issues concerning the coating process (layout and runnability issues) and the coated paper (base paper, coating and surface properties).