Valmet Aktiebolag

Valmet Ab

Michael Bjerke

Dennis Edward Jewitt

Danilo Marcos

Mattias Johansson

Viktor Bergström

Bruno Tremblay

Petter Ericsson

Dennis Jewitt

The invention relates to a method and system for improving the application of a coating on a Yankee cylinder (CR) in tissue paper machines. The invention implements a moisture-controlled environment () in an area of the exposed Yankee cylinder between the take-off position (TO) and ahead of the transfer position (TP) of the web, i.e. before and/or after the application of a coating with Performance Enhancing Material (PEM), wherein the cooling effect on the Yankee surface is increased by increased evaporation rate of water in the coating or water additionally applied onto the coating.

Method and a system for a Yankee cylinder in a tissue machine

The invention relates to a method of transferring a tissue web with residual moisture to a Yankee cylinder and final removal of the dried tissue web from the Yankee cylinder using a doctor blade and collecting the dried web on a reel-up machine forming a tissue reel. The invention also relates to the Yankee adhesive composition per se. The method involves preparation of a water solution of a Yankee adhesive composition with less than 10% final solids content to be applied on the surface of the Yankee cylinder ahead of transferring the tissue web with residual moisture to the Yankee cylinder. The inventive method applies an aqueous PVOH solution with a very high molecular weight polyvinyl alcohol as a part of the solid content of the Yankee adhesive in an amount ranging from 20-65% of the final solids content of the Yankee adhesive. The aqueous PVOH solution with the very high molecular weight polyvinyl alcohol establish a viscosity ranging from 90 cP to 300 cP.

Yankee adhesive compositions and methods of using these compositions

The invention relates to a suction device () for use in a papermaking machine and being suitable for acting on a wet fibrous web through a permeable fabric (), e.g. a through-air-drying (TAD)-fabric. The suction device has a fabric-facing surface () formed by a plurality of end surfaces of solid elements (). Channels () are defined between the solid elements. The end surface of the final solid element () does not lie in the same plane as the end surfaces of the previous solid elements (). Thereby, a gap A is formed between the fabric () and the final solid element (). This allows air to flow through the gap and into a final channel (). The air flow will then catch fines, small fibers and water droplets and draw them into the final channel () thereby counteracting a build-up of large lumps of fines and fibers.

Suction device for use in a papermaking machine and a papermaking machine using a suction device

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Hammaroe, Sweden

Michael Bjerke