Patent ID: 6432273
Filing Date: 2002-08-13
Classification: D21F

Abstract:
A method for transferring a paper web (W) from a former paper section (100) of a paper machine to a press section (110) thereof, said former section (100) having a lower wet wire loop (20) and an upper wet wire loop (10), said lower wire and said upper wet wire defining a twin-wire forming zone, said press section having at least one dewatering press nip (N1; N1,N2), and a pre-press zone (PP) structured and arranged between said former section (100) and said press section (110) for removing water from said web (W) passing therethrough as a closed draw from said former section (100) to said press section (110), comprising the steps of:providing at least a first pressure difference device (15, 16) interiorly of said loop of said upper wet wire and at least a second pressure difference device (26) interiorly of said loop of said lower wet wire for applying a pressure to said paper web (W); and applying a pressure difference to said paper web (W) through said lower wet wire (20) and said -upper wet wire (10) after the formation of said paper web (W), such that, a higher pressure is applied on one of: a side of said upper wet wire (10) in order for said paper web (W) to follow said lower wet wire (20) during a threading operation or during an operational malfunction, and a side of said lower wet wire (20) in order for said paper web (W) to follow along said upper wet wire (10) during normal operating conditions.