Metso Paper Inc.

Valmet Corporation

Tapio M&auml;enpaa

Eero Suomi

Vesa Ij&auml;s

Arto Karjalainen

The invention relates to a method by means of which the machine-direction moisture of a web being calendered or coated and calendered can be controlled in an optimal manner that takes into account moisture content changes along the entire path of the coating and drying process. Advantageously, all the dryers and the calender of the coater section are controlled in an integrated manner in order to obtain a controlledly processed product which is optimized in regard to energy consumption and product quality. Each process section and unit contributing to the drying of the web is identified by means of a mathematical submodel describing the specific evaporation rate in the respective process section/unit and, by chaining these submodels, a composite model is compiled for the entire process, whereby the composite model makes it possible to manage the drying operation in the process so that the individual units are controlled as a portion of the overall process. In its simplest form, the composite model of the overall process comprises a submodel describing the behavior of the calender and at least one partial submodel describing the web processing unit preceding the calender.

Method for controlling the moisture of a web in machine direction on a coating machine and calender

A method for detecting contamination on or damage to a web-contacting face in a paper machine or a paper finishing machine, including the steps of detecting vibrations of the web-contacting face over a period of time by means of a plurality of detectors arranged in association with the machine and determining the location of the contamination on or damage to the web-contacting face based on the time the vibrations were detected.

Growing community of inventors

Helsinki, Finland

Tapio Mäenpaa

Growing community of inventors

Helsinki, Finland

Tapio M&auml;enpaa

Tapio Mäenpaa