Method for controlling deposit formation

Abstract

The invention relates to a method for controlling deposit formation on paper machine rolls, said method comprising applying at the dry end of a paper machine an aqueous solution of an anionic or non-ionic polymer on the surface of the paper for preventing the rolls from being contaminated by stickies and/or other depositable material from the paper.

1 . A method for controlling deposit formation on paper machine rolls, said method comprising applying at the dry end of a paper machine an aqueous solution of an anionic or non-ionic polymer on the surface of the paper for preventing the rolls from being contaminated by stickies and/or other depositable material from the paper. 
     
     
         2 . The method of  claim 1  wherein the paper machine rolls are calender rolls. 
     
     
         3 . The method of  claim 2  wherein the calender rolls include thermo rolls. 
     
     
         4 . The method of  claim 3  wherein the surface temperature of the thermo rolls is at least 100° C. 
     
     
         5 . The method of  claim 1  wherein the anionic polymer comprises a condensation product of an aromatic sulphonic acid with formaldehyde. 
     
     
         6 . The method of  claim 1  wherein the aqueous solution of the anionic or non-ionic polymer is applied in an amount ranging from 0.001 to 0.5 gram per m 2  of the surface of the paper per side of the paper calculated as active substance. 
     
     
         7 . The method of  claim 6  wherein the aqueous solution of the anionic or non-ionic polymer is applied in an amount ranging from 0.01 to 0.03 gram per m 2  of the surface of the paper calculated as active substance. 
     
     
         8 . The method of  claim 1  wherein the aqueous solution of the anionic or non-ionic polymer is applied on both sides of the paper. 
     
     
         9 . The method of  claim 1  wherein the applying is made by spraying. 
     
     
         10 . The method of  claim 2  wherein the paper machine is equipped with a moistening shower or showers downstream of the calender rolls, said aqueous solution of the anionic or non-ionic polymer being sprayed by means of said moistening shower(s). 
     
     
         11 . The method of  claim 5 , wherein the condensation product of an aromatic sulphonic acid with formaldehyde comprises naphthalenesulphonate formaldehyde condensate.