Producing half-stuffs for the manufacture of papery articles

Abstract

The present invention relates to a process for producing half-stuffs for the manufacture of papery articles which comprises adding methanesulfonic acid to an aqueous fibrous suspension to set the pH.

1 - 11 . (canceled) 
     
     
         12 . A process for producing a half-stuff for the manufacture of papery articles comprising the steps of:
 a) providing an aqueous composition comprising at least one fibrous material;   b) adding methanesulfonic acid to the aqueous composition comprising at least one fibrous material to set the pH; and   c) optionally at least one further process step for producing a half-stuff   
     
     
         13 . The process according to  claim 12 , wherein the aqueous composition comprises at least one fibrous material selected from the group consisting of sulfate pulp (SA), sulfate semi-chemical pulp, sulfite pulp (SI), groundwood (HS), pressurized groundwood (PGW), refiner mechanical pulp (RMP), thermomechanical pulp (TMP), chemical thermomechanical pulp (CTMP), thermomechanical pulp with caustic/peroxide pretreatment (BCTMP), wastepaper (AP) and deinked pulp (DIP). 
     
     
         14 . The process according to  claim 12 , wherein the aqueous composition comprises at least one fibrous material which has been alkali-oxidatively bleached. 
     
     
         15 . The process according to  claim 12 , wherein the pH of the aqueous composition is set in step b) to a value in the range from 4 to 11. 
     
     
         16 . The process according to  claim 12 , wherein the aqueous composition in step a) has a stock density in the range from 0.1 to 45%. 
     
     
         17 . The process according to  claim 12 , wherein step b) is followed by an at least partial dewatering of the aqueous composition. 
     
     
         18 . The process according to  claim 12 , wherein step b) is followed by a dewatering of the aqueous composition to a stock density in the range from 80 to 90% (oven dry). 
     
     
         19 . The process according to  claim 12 , wherein step b) is followed by a dewatering of the aqueous composition to a stock density in the range from 10 to 30% (oven dry). 
     
     
         20 . The process according to  claim 12 , wherein step a) is preceded by at least one alkaline bleaching and/or preparation step. 
     
     
         21 . The process according to  claim 12 , wherein step a) is preceded by at least one oxidative bleaching step by addition of at least one peroxide compound in the alkaline pH range. 
     
     
         22 . The process according to  claim 12 , wherein step a) is preceded by at least one deinking step of a secondary fibrous material.