A METHOD OF MAKING A STRUCTURED FIBROUS WEB AND A CREPED FIBROUS WEB

摘要

The invention relates to a method of making a structured fibrous web (W). The method comprises forming a fibrous web (W) and conveying the formed fibrous web on a water receiving felt (5) to a dewatering nip (PN) formed by a first press unit (8) and a second press unit (9) and where an endless belt (11) is passed through the nip together with the fibrous web 5 (W) and the water receiving felt (5), The endless belt has a side which is covered by a polymer and which contacts the fibrous web (W) in the dewatering nip (PN). After the dewatering nip, the web (W) is transferred with a speed difference to an endless structured clothing (12) which is permeable to air and has protruding knuckles (40) on the side that contacts the fibrous web (W) and which protruding knuckles (49) give the structured clothing (12) a topographic surface 10 area which, for a given length of the structured clothing (12) in the machine direction and a given width of the structured clothing in the cross machine direction, exceeds the plain surface area of a part of the endless belt (11) having an equal length and width. The structured clothing is operated at a speed which is so much lower than the speed of the endless belt (11) that the relative difference in speed between the endless belt (11) and the structured (12) fabric 15 corresponds to the relative difference in surface area between the endless belt (11) and the structured clothing. In this way, the fibers of the fibrous web (W) will be evenly distributed on the structured clothing (12). The invention also relates to a creped fibrous web (W) having a basis weight in the range of 14 g/m2 – 40 g/m2, and having a three-dimensional structure formed by depressed regions (45) and elevated regions (46). The fibers of the fibrous web (W) are 20 evenly distributed over the surface of the creped fibrous web (W).