Process for Producing Paper or Paperboard, in Particular Label Paper or Paperboard Suited for Use as Packaging Material for Beverage Containers, and Paper or Paperboard Produced by This Process

Abstract

A method for producing label paper or paper for corrugated board or folding carton for packaging of beverage containers has the steps of feeding wood fiber pulps into a papermaking process and forming a web mixture. The web mixture has the wood fiber pulp, a cationic polymer, an anionic polymer, and a cationic starch. The cationic starch is added to the wood fiber pulp only after the addition of the anionic polymer and cationic polymer.

1 . A method for producing label paper or corrugated board or folding carton for packaging of beverage containers, comprising the steps of:
 feeding wood fiber pulps into a paper-making process;   forming a web mixture comprising the wood fiber pulp, a cationic polymer, an anionic polymer and a cationic starch;   wherein the cationic starch is added to the wood fiber pulp only after the addition of the anionic polymer and cationic polymer.   
     
     
         2 . The method according to  claim 1 , the cationic polymer is added to the wood fiber pulp prior to the addition of the anionic polymer. 
     
     
         3 . The method according to  claim 1 , wherein the cationic polymer comprises polyamideamine epichlorohydrin (PAE). 
     
     
         4 . The method according to  claim 3 , the amount of PAE added to the wood fiber pulp ranging between 1 and 40 kg/ton of wood fiber pulp (dry weight), preferably between 1.5 and 4.5 kg/ton of wood fiber pulp (dry weight). 
     
     
         5 . The method according to  claim 1 , wherein the anionic polymer comprises carboxy methyl cellulose (CMC). 
     
     
         6 . The method according to  claim 5 , the amount of CMC added to the wood fiber pulp ranging between 0.1 and 10 kg/ton of wood fiber pulp (dry weight), preferably between 0.5 and 2 kg/ton of wood fiber pulp (dry weight). 
     
     
         7 . The method according to  claim 1 , the amount of cationic starch added to the wood fiber pulp ranging between 1 and 40 kg/ton of wood fiber pulp (dry weight), preferably between 5 and 15 kg/ton of wood fiber pulp (dry weight). 
     
     
         8 . The method according to  claim 1 , comprising providing a reaction time in between the addition of cationic polymer and the addition of anionic polymer to the web mixture of wood fiber pulp. 
     
     
         9 . The method according to  claim 1 , comprising providing a reaction time in between the addition of anionic polymer and the addition of cationic starch to the web mixture of wood fiber pulp. 
     
     
         10 . A fiber product, comprising:
 a fiber web; and   an at least partially cured resin composition,   
       wherein, preferably prior to curing, the resin composition comprises:
 a cationic polymer, preferably polyamide-epichlorohydrin; 
 an anionic polymer, preferably carboxymethyl cellulose; and 
 cationic starch, wherein the cationic starch is added after the addition of the anionic polymer and the cationic polymer, 
 wherein the fiber product has a wet tensile strength of at least 7 N·m/g (ISO3781:2011) and/or a wet tear resistance of at least 9 mN·m 2 /g, preferably at least 9.5 mN·m 2 /g (ISO1794:2012).