NZ510272A - Method of producing high gloss paper utilising vacuolated particulated plastic sheet backing during calendering - Google Patents

Abstract

A method of producing a finished paper or paperboard having high gloss and high bulk, comprising: a) forming a base stock; b) applying to at least one side of the base stock a first layer of a coating formulation comprising a vacuolated particulate plastic pigment to form a coated base stock; and c) passing the coated base stock through the nips of a multi-nip calender device; wherein said calender device is comprised of one or more hard rolls and one or more soft rolls in linear arrangement, the interface between each pair of rolls forming a nip; wherein said calender device maintains a nip load at the initial nip of substantially 70.3 k/cm2 (1000 pli) or less, a nip load at each of the intervening nips of up to substantially 70.3 k/cm2 (1000 pli) or less; and a nip load at the final nip of substantially 70.3 k/cm2 (1000 pli) or less; and wherein the surface temperature of the one or more hard rolls does not exceed substantially 232ºC (450ºF); to form a product having a TAPPI 75º gloss value of greater than 60 and a density of substantially 3.19 kg/278.7m2/0.0254 cm (15.5 pounds per ream per caliper point (lbs./ream/pt)) to substantially 9.07 kg/278.7 m2/0.00254 cm (20 lbs./ream/pt), which corresponds inversely to a basis weight of from substantially 22.68 kg/278.7 m2 (50 lbs./ream) to substantially 68.03 kg/278. 7m2 (150 lbs./ream), wherein the term 'vacuolated' in part b) is as herein defined.