Method and arrangement for calendering paper and board before and after coating
AssigneeValmet Corporation
InventorsPauli Kytönen, Mikko Tani
Life of this patent
Estimating the term…
Abstract
A method and apparatus for calendering paper or board in the manufacture of coated grades of paper or board. At least one of the surfaces of an uncoated base material web is calendered, at least one layer of coating mix being applied onto said surface, and at least the coated surface of the base web is calendered again. The uncoated surface of the base web is calendered by means of a shoe calender having a nip length of at least 50 mm, and the coated surface of the base web is calendered by means of a calender having a nip length of 50 mm at the most.
Claims21
A method for a calendering paper and board web when manufacturing coated grades of paper or board comprising:
- calendering at least one of the surfaces of an uncoated base web with a shoe calender having a nip length of at least 50 mm to form at least one calendered surface;
- applying at least one layer of coating at least onto the at least one calendered surface of the base web to form at least one coated surface;
- and
- calendering the at least one coated surface of the base web with a calender having a nip length of less than and not equal to 30 mm.
An apparatus for calendering a paper and board web when manufacturing coated grades of paper or board comprising:
- a first calender for calendering at least one of the surfaces of an uncoated base web to form at least one calendered surface, the first calender comprising a shoe calender having a nip length of at least 50 mm;
- a means for applying at least one layer of coating at least onto the at least one calendered surface of the base web to form at least one coated surface;
- and
- a second calender for calendering at least the at least one coated surface of the base web, the second calender having a nip length of less than and not equal to 30 mm.
Dependencies are inferred from the claim text.