| 摘要 |
PROBLEM TO BE SOLVED: To obtain a bulking paper having an excellent bulkiness and rigidity and suitable as printing paper and information business paper by treating a pulp fiber sheet with liquid ammonia. SOLUTION: A bulking paper containing 20-60wt.% of pulp fiber having an average flatness of 1.2-1.6 based on the dry fiber weight is produced by immersing a pulp fiber sheet produced from bleached hardwood kraft pulp and having an areal weight of 60-300g/m<2> and a density of 0.4-0.75g/m<3> in a liquid ammonia bath maintained at -40 to -60 deg.C, squeezing the sheet to remove excess ammonia and drying with a through-drier or a multicylinder drier at 20-40 deg.C. |
