CARDBOARD WITH LOW BULK DENSITY Russian patent published in 2013 - IPC D21H11/04 D21H17/63 D21H17/67 D21H19/20 D21H19/36 D21H19/54 

FIELD: textiles, paper.

SUBSTANCE: cardboard comprises solid cardboard substrate of bleached sulphate pulp (BSP) and a coating applied to the cardboard substrate to form a coated structure. The said coated structure has a surface density, thickness of the sheet and the Parker surface smoothness. The Parker surface smoothness is at most about 3 microns, and the surface density is at most about Y₂ or Y₃ or Y₄ pound/3000 foot², where Y₂, Y₃ and Y₄ are functions of the said thickness (X) of the sheet in points which are calculated using the equation: Y₂=3.71+13.14X-0.1602X² or Y₃=3.63+12.85X-0.1566X², or Y₄=3.50+12.41X-0.1513X².

EFFECT: invention provides a coated cardboard with increased smoothness with the required parameters of thickness and the surface density to ensure high-quality printing.

13 cl, 10 dwg, 1 tbl, 6 ex