Process and apparatus for producing a tissue web
AssigneeVoith Patent GmbH
InventorsThomas Scherb, Luiz Carlos Silva, Davilo Oyakawa, Rogerio Berardi
Life of this patent
Estimating the term…
Abstract
A process for producing a fibrous web, in particular a tissue web, includes the following steps: in a pressing zone, the fibrous web is pressed lying between the structured belt and a circulating, unstructured permeable supporting belt; the fibrous web and the structured belt are fed to a press nip provided on a Yankee cylinder; the fibrous web is transferred from the structured belt to the surface of the Yankee cylinder in the region of the press nip; and the surface of the Yankee cylinder is doctored off continuously and then recoated again, so that a renewed coating is always present in the press nip.
Claims28
A process for producing a fibrous web, comprising the steps of:
- pressing the fibrous web in a pressing section between a circulating permeable structured belt and a circulating unstructured permeable supporting belt;
- feeding the fibrous web and said structured belt to a press nip defined by a Yankee cylinder, an outlet pocket between the fibrous web and said structured belt being acted on by an air knife, said outlet pocket occurring at an outlet from said press nip;
- transferring the fibrous web from said structured belt to a surface of said Yankee cylinder in a region of said press nip;
- doctoring off continuously said surface of said Yankee cylinder and removing at least partially a coating material applied to said surface of said Yankee cylinder;
- and
- recoating said surface of said Yankee cylinder so that a renewed said coating material is always present in said press nip.
A process for producing a fibrous web, comprising the steps of:
- pressing the fibrous web in a pressing section between a circulating permeable structured belt and a circulating unstructured permeable supporting belt;
- feeding the fibrous web and said structured belt to a press nip defined by a Yankee cylinder;
- transferring the fibrous web from said structured belt to a surface of said Yankee cylinder in a region of said press nip;
- doctoring off continuously said surface of said Yankee cylinder and thereby removing at least partially a coating material applied to said surface of said Yankee cylinder;
- recoating said surface of said Yankee cylinder so that a renewed said coating material is always present in said press nip;
- and
- creping the fibrous web, wherein in order to doctor off said surface of said Yankee cylinder continuously and to crepe the fibrous web, at least one doctor is loaded in such a way that a line force in a range from about 3 to about 7 kN/m results.
Dependencies are inferred from the claim text.