MULTI-LAYER WEB FORMATION SECTION

摘要

Multi-layer web formation section having at least two successive wire units (300, 310). A first headbox (100) supplies a pulp suspension jet to the forward end of the first wire unit (300) to form a first partial web (W1). A second headbox (110) supplies a pulp suspension jet into a jaw (G2) at the forward end of the second wire unit (310) to form a second partial web (W2). The second partial web (W2) is joined to the first partial web (W1) at a joint (N1) in between the second wire unit (310) and a bottom wire (11). In the forward end of a two-wire stretch of the second wire unit (310) there is a first non-pulsating dewatering zone (Z1b), which is formed by a fixed first formation shoe (200b), which has a curved cap (201) placed against one side of the two-wire stretch and provided with openings (202) extending through the cap (201), and an under-pressure (P) affecting through the cap's (201) openings (202). A two-wire stretch of the second wire unit (310) has a second pulsating dewatering zone (Z2b), which is formed by fixed dewatering lists (210b) in the cross machine direction, between which there are gaps (220b), and an under-pressure (Pb) affecting in these.