Effects of shoe pressing on fine paper properties

A series of trials has been conducted on a Pilot paper machine to investigate the effect of shoe pressing on the web solids contents and proper ties of fine paper The machine was operated at speeds of 600 and 700 m/min, and the shoe press nip load ranged from to 50 to 700 kN/m. Adequate bulk and a solids content of 45% were obtained when fine paper was pressed by two lightly loaded roll presses and a shoe press. Solids contents in excess of 47% were obtained when paper was Pressed by four heavily loaded presses, one of which was a shoe press, but the bulk was about 10% lower than the bulk of paper lightly pressed in a three-roll press. Pressed to equal solids contents, paper pressed by a shoe press had a higher bulk and opacity, but lower Scott bond and strength than paper pressed in roll presses only.