Twin wire former with roll press followed by extended nip press

Claim 1

A apparatus for making a paper web from stock, said apparatus having a direction of web travel and comprising: first and second forming wire loops cooperating together to define therebetween a substantially horizontal web forming section having a first and a second end; a headbox disposed adjacent to said first end of said forming section for ejecting the stock between said wires such that the web is formed in the direction of web travel from the stock during passage of the stock from said first towards said second end of said forming section; a first felt disposed downstream in the direction of web travel relative to said forming section, said first felt running contiguously relative to said second wire in the second wire loop such that said second wire is disposed between said first felt and the web; a second felt disposed downstream in the direction of web travel relative to said forming section and on the opposite side of the web relative to said first felt; an open roll looped by said first felt; a suction roll looped by said second felt and cooperating with said open roll for defining therebetween a first press nip for pressing a first portion of water from the formed web; a backing roll disposed downstream in the direction of web travel relative to said first nip; and an extended nip press shoe cooperating with said backing roll for defining therebetween an extended nip such that said second felt and the web extend through said extended nip for removing a second portion of water from the web.

Claim 2

A apparatus for making a paper web from stock, said apparatus having a direction of web travel and comprising: first and second forming wire loops cooperating together to define therebetween a substantially horizontal web forming section having a first and a second end; a headbox disposed adjacent to said first end of said forming section for ejecting the stock between said wires such that the web is formed in the direction of web travel from the stock during passage of the stock from said first towards said second end of said forming section; a first felt disposed downstream in the direction of web travel relative to said forming section, said first felt running contiguously relative to said second wire in the second wire loop such that said second wire is disposed between said first felt and the web; a second felt disposed downstream in the direction of web travel relative to said forming section and on the opposite side of the web relative to said first felt; an open roll looped by said first felt; a suction roll looped by said second felt and cooperating with said open roll for defining therebetween a first press nip for pressing a first portion of water from the formed web; a backing roll disposed downstream in the direction of web travel relative to said first nip; and an extended nip press shoe cooperating with said backing roll for defining therebetween an extended nip such that said second felt and the web extend through said extended nip for removing a second portion of water from the web.

Claim 12

An apparatus as set forth in claim further including: a steam box disposed on one side of the web between said first nip and said extended nip; a vacuum box disposed adjacent to said steam box, said vacuum box being disposed on the opposite side of the web relative to said steam box for heating the web prior to passage of the web through said extended nip.

Claim 14

An apparatus for making a paper web from stock, said apparatus having a direction of web travel comprising: first and second forming wire loops cooperating together to define therebetween a substantially horizontal web forming section having a first and a second end; a headbox disposed adjacent to said first end of said forming section for ejecting the stock between said wires such that the web is formed in the direction of web travel from the stock during passage of the stock from said first towards said second end of said forming section; a first felt disposed in the direction of web travel relative to said forming section, said first felt running contiguously relative to said second wire in the second wire loop such that said second wire is disposed between said first felt and the web; a second felt disposed downstream in the direction of web travel relative to said forming section and on the opposite side of the web relative to said first felt; an open roll looped by said first felt; a suction roll looped by said second felt and cooperating with said open roll for defining therebetween a first press nip for pressing a first portion of water from the formed web; a backing roll looped by said second felt and disposed downstream in the direction of web travel relative to said first nip; an extended nip press shoe cooperating with said backing roll for defining therebetween an extended nip such that said second felt and the web extend through said extended nip for removing a second portion of water from the web, said second felt being disclosed between the web and said backing roll; a steam box disposed on one side of the web between said first nip and said extended nip; and a vacuum box disposed adjacent to said stem box, said vacuum box being on the opposite side of the web relative to said steam box for heating the web prior to passage of the web through said extended nip.

Claim 15

An apparatus for making a paper web from stock, said apparatus having a direction of web travel comprising: first and second forming wire loops cooperating together to define therebetween a substantially horizontal web forming section having a first and a second end; a headbox disposed adjacent to said first end of said forming section for ejecting the stock between said wires such that the web is formed in the direction of web travel from the stock during passage of the stock from said first towards said second end of said forming section; a first felt disposed in the direction of web travel relative to said forming section, said first felt running contiguously relative to said second wire in the second wire loop such that said second wire is disposed between said first felt and the web; a second felt disposed downstream in the direction of web travel relative to said forming section and on the opposite side of the web relative to said first felt; an open roll looped by said first felt; a suction roll looped by said second felt and cooperating with said open roll for defining therebetween a first press nip for pressing a first portion of water from the formed web; a backing roll looped by said second felt and disposed downstream in the direction of web travel relative to said first nip; an extended nip press shoe cooperating with said backing roll for defining therebetween an extended nip such that said second felt and the web extend through said extended nip for removing a second portion of water from the web, said second felt being disclosed between the web and said backing roll; a steam box disposed on one side of the web between said first nip and said extended nip; and a vacuum box disposed adjacent to said stem box, said vacuum box being on the opposite side of the web relative to said steam box for heating the web prior to passage of the web through said extended nip.

Claim 16

A method for making a paper web from stock, said method comprising the steps of: ejecting the stock from a headbox between a first and a second forming wire which cooperate together to define therebetween a substantially horizontal web forming section having a first and a second end; forming the web during passage of the stock from the first to the second end of the forming section; supporting the formed web on the second wire and guiding the formed web on the second wire through a first press nip defined by an open roll and a cooperating suction roll, the first press nip being disposed downstream relative to the forming section; guiding a first felt disposed downstream relative to the forming section through said first press nip, the first felt running contiguously relative to the second wire such that the second wire is disposed between the first felt and the web and such that said first felt loops the open roll; transferring the pressed web to a second felt which extends through the first press nip and which loops around the suction roll; applying steam to the press web downstream relative to the first press nip for heating the web; and further pressing the pressed web by guiding the pressed, heated web and said second felt through an extended nip press.

Claim 17

A method for making a paper web from stock, said method comprising the steps of: ejecting the stock from a headbox between a first and a second forming wire which cooperate together to define therebetween a substantially horizontal web forming section having a first and a second end; forming the web during passage of the stock from the first to the second end of the forming section; supporting the formed web on the second wire and guiding the formed web on the second wire through a first press nip defined by an open roll and a cooperating suction roll, the first press nip being disposed downstream relative to the forming section; guiding a first felt disposed downstream relative to the forming section through said first press nip, the first felt running contiguously relative to the second wire such that the second wire is disposed between the first felt and the web and such that said first felt loops the open roll; transferring the pressed web to a second felt which extends through the first press nip and which loops around the suction roll; applying steam to the press web downstream relative to the first press nip for heating the web; and further pressing the pressed web by guiding the pressed, heated web and said second felt through an extended nip press.