Paper or paperboard laminate and method to produce such a laminate
First Claim
1. Paper or paperboard laminate composed of at least one bulk-promoting layer, and on at least one side of said bulk layer at least one secondary layer, said secondary layer and said bulk layer being joined to one another directly or indirectly over basically the whole of their surfaces facing one another, wherein 40-95% of said bulk layer consists of cellulose fibers with a freeness of 550-950 ml CSF, said at least one secondary layer having a greater density than said bulk layer, and said laminate having a bending stiffness index higher than 2.5 Nm7/kg3, but less than 14 Nm7/kg3, calculated as a geometric mean value for machine and transverse direction.
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Accused Products
Abstract
Paper or paperboard laminate composed of at least one bulk-promoting layer, here termed the bulk layer, and on at least one side at the bulk layer at least one secondary layer, secondary layer and bulk layer being joined to one another directly or indirectly over basically the whole of their surfaces facing one another, 40-95% of the bulk layer consists of cellulose fibers with a freeness of 550-950 ml CSF, the secondary layer/layers has/have a greater density than the bulk layer, and the laminate has a bending stiffness index higher than 2.5 Nm7/kg3, but less than 14 Nm7/kg3, calculated as a geometric mean value for machine and transverse direction.
58 Citations
88 Claims
- 1. Paper or paperboard laminate composed of at least one bulk-promoting layer, and on at least one side of said bulk layer at least one secondary layer, said secondary layer and said bulk layer being joined to one another directly or indirectly over basically the whole of their surfaces facing one another, wherein 40-95% of said bulk layer consists of cellulose fibers with a freeness of 550-950 ml CSF, said at least one secondary layer having a greater density than said bulk layer, and said laminate having a bending stiffness index higher than 2.5 Nm7/kg3, but less than 14 Nm7/kg3, calculated as a geometric mean value for machine and transverse direction.
- 71. Method of producing a paper or paperboard laminate composed of at least one bulk-promoting layer, here termed the bulk layer, and on at least one side of the bulk layer at least one secondary layer, secondary layer and bulk layer being joined to one another directly or indirectly over basically the whole of their surfaces facing one another, wherein chosen or produced as the bulk layer (1) is a layer of which 40-95 percent by weight consists of cellulose fibers with a freeness of 550-950 ml CSF, which bulk layer is joined at least on its one side directly or indirectly to a secondary layer (2a, 2b), which has a greater density than the bulk layer, to form a laminate with a bending stiffness index higher than 2.5 Nm7/kg3, but lower than 14 Nm7/kg3, calculated as a geometric mean value for machine and transverse direction.
Specification