IMPROVEMENT OF THERMAL AND MECHANICAL DEWATERING OF PAPER IN A HOT PRESS NIP SIMULATOR

A laboratory-scale apparatus has been developed to investigate the the rmal and mechanical dewatering of paper in the press nip of a high spe ed paper machine. The apparatus is basically a hammer-and-anvil-type d ynamic press simulator modified to also simulate hot nip conditions. U sing this device, dewatering experiments have performed on household p aper tissue over a wide range of press conditions. The influence of di fferent underlays, maximum pressure and temperature on mechanical dewa tering by compression, capillary transfer between porous compressible materials, thermal drying and rewetting of the sheet are discussed.