Sheet forming device and method for sheet forming

Abstract

Plies that are formed by respective formers are couched together in a sheet forming device, specifically a machine for the production of a multi-ply fiber web, particularly a paper or cardboard web, or a packaging paper web. At least one of the formers for forming a multi-ply web includes a multi-layer headbox, to which at least two different stocks, or stock partial streams of different composition for different plies are furnished.

1 . A sheet forming device for the production of a multi-ply fiber web, specifically one of paper, cardboard and packaging paper in which at least two plies, formed by corresponding formers, are couched together comprising: 
 a plurality of formers, at least one of said plurality of formers comprising a multi-layer headbox for receiving at least two of stocks and stock partial streams of different compositions for different plies.    
   
   
       2 . The device of  claim 1 , wherein said at least two of different stocks and stock partial streams include at least two of long fiber fraction, long fiber/short fiber fraction, short fiber fraction, fines poor fraction, fines poor/fines rich fraction and fines rich fraction.  
   
   
       3 . The device of  claim 2 , wherein said plurality of formers include a first former and a second former, said second former having said multi-layer headbox, at least one of said long fiber fraction and said fines poor fraction being supplied to said first former, at least one of said long fiber/short fiber fraction, said short fiber fraction, said fines poor/fines rich fraction and said fines rich fraction being furnished to said multi-layer headbox.  
   
   
       4 . The device of  claim 3 , wherein said first former forms a liner layer.  
   
   
       5 . The device of  claim 2 , wherein at least one of said plurality of formers includes at least one former having an outer wire and an inner wire, at least one of said long fiber/short fiber fraction, said short fiber fraction, said fines poor/fines rich fraction and said fines rich fraction being furnished to said at least one former, said outer wire dewatering at least one of said long fiber/short fiber fraction and said fines poor/fines rich fraction, said inner wire dewatering at least one of said short fiber fraction and said fines rich fraction.  
   
   
       6 . The device of  claim 2 , further comprising a base wire, whereupon a liner layer is formed by at least one of said long fiber fraction and said fines poor fraction, a backing layer is formed by at least one of said long fiber/short fiber fraction and said fines poor/fines rich fraction and a center layer is formed by at least one of said short fiber fraction and said fines rich fraction between said liner layer and said backing layer.  
   
   
       7 . The device of  claim 2 , wherein said plurality of formers include at least one Gapformer, said Gapformer including a forming element, said forming element being a forming roll.  
   
   
       8 . The device of  claim 7 , wherein at least one of said long fiber/short fiber fraction, said short fiber fraction, said fines poor/fines rich fraction and said fines poor fraction are fed to said Gapformer thereby forming a sheet, said sheet having at least one of said short fiber and said fines rich fraction forming proximate said forming element.  
   
   
       9 . The device of  claim 1 , wherein the device is configured for the packing segment.  
   
   
       10 . The device of  1 , further comprising: 
 a press section;    a dryer section; and    at least one of a coating device, an applicator device and a rewinder.    
   
   
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