摘要 |
<p>Paper or paperboard laminate composed of at least one bulk-promoting layer, here termed bulk layer ( 1 ), 40-98% of which is composed of cellulose fibers with a freeness value of 550-950 ml CSF, and on at least one side of the bulk layer at least one secondary layer ( 3 a , 3 b'), which has a greater density than the bulk layer, the secondary layer and bulk layer being joined indirectly to one another over basically the whole of their opposing surfaces and the laminate having a bending stiffness index greater than 2.5 Nm<SUP>7</SUP>/kg<SUP>3</SUP>, but less than 14 Nm<SUP>7</SUP>/kg<SUP>3</SUP>, calculated as a geometric mean value for machine direction and cross direction. According to the invention a thin intermediate layer ( 2 a), which has a higher drainage resistance than the bulk layer and has been formed together with the bulk layer, is arranged between the said bulk layer ( 1 ) and secondary layer ( 3 a , 3 b').</p> |