Core raw paper for corrugated boards, and method of producing the same

Abstract

A method of producing core raw paper is provided that prevents corrugation cracking, corrugation cutting or breakage from occurring during corrugating operation using a corrugating roll, prevents the wearing of the corrugating roll, reduces the consumption of driving power and noise, is capable of uniformly and efficiently coating the core raw paper with wax, and does not pollute facilities such as a paper machine. A method of producing core raw paper for corrugated boards coated with wax by a paper machine having a plurality of driers, comprising the steps of spraying, as at (S), the surface of a drier (C 8 ) with a dispersion containing the wax, changing the wax into oil on the surface of the heated drier (C 8 ), and pressing the surface of the drier (C 8 ) against core raw paper ( 100 ) to thereby transfer the oil-changed wax from the surface of the drier (C 8 ) to the core raw paper ( 100 ).

1 . Core raw paper for corrugated boards coated with wax on the face and the back wherein the amount of wax applied on said core raw paper is in a range of 0.1-10 mg/m 2 .  
     
     
         2 . Core raw paper for corrugated boards according to  claim 1  wherein the moisture content of said core raw paper is less than 10% when wax is applied.  
     
     
         3 . Core raw paper for corrugated boards according to  claim 1  wherein a dispersion containing wax is sprayed over the last drier of the paper machine and the wax contained in said dispersion is transferred and applied on core raw paper.  
     
     
         4 . Core raw paper for corrugated boards according to  claim 1  wherein the dispersion containing wax is sprayed over a paper roll of the paper machine and the wax contained in said dispersion is transferred and applied on core raw paper.  
     
     
         5 . A method of producing core raw paper for corrugated boards coated with wax using a paper machine provided with a plurality of groups of driers wherein a dispersion containing said wax is sprayed over the surface of the driers, the wax is oil-changed on the surface of the heated driers, and the oil-changed wax is transferred from the surface of the driers onto the face of core raw paper.  
     
     
         6 . The method of producing core raw paper for corrugated boards according to  claim 5  wherein said driers are the driers belonging to the last group of the paper machine.  
     
     
         7 . The method of producing core raw paper for corrugated boards according to  claim 5  wherein said driers are the last driers of the upper or lower rows among the driers belonging to the last group.  
     
     
         8 . The method of producing core raw paper for corrugated boards according to  claim 5  wherein the melting point of said wax is lower than the surface temperature of the driers.  
     
     
         9 . A method of producing core raw paper for corrugated boards coated with wax by using a paper machine provided with a paper roll wherein a dispersion containing said wax is sprayed over the surface of said paper roll and said wax is transferred from the surface of said paper roll onto the face of core raw paper.  
     
     
         10 . The method of producing core raw paper for corrugated boards according to  claim 5  or  claim 9  wherein said wax is applied in such a way that the amount of wax applied to core raw paper would be in a range of 0.1-10 mg/m 2 .  
     
     
         11 . The method of producing core raw paper for corrugated boards according to  claim 5  or  claim 9  wherein the moisture content of said core raw paper is less than 10% when the dispersion containing wax is sprayed.  
     
     
         12 . The method of producing core raw paper for corrugated boards according to  claim 5  or  claim 9  wherein said wax, after having transferred onto the face of core raw paper, partially is transferred to the back of core raw paper by the winding of core raw paper.  
     
     
         13 . The method of producing core raw paper for corrugated boards according to  claim 5  or  claim 9  wherein for said wax paraffin wax, polyethylene wax or micro wax is used singly or in combination.  
     
     
         14 . The method of producing core raw paper for corrugated boards according to  claim 5  or  claim 9  wherein said dispersion further contains a solid lubricant or a metal soap.  
     
     
         15 . The method of producing core raw paper for corrugated boards according to  claim 5  or  claim 9  wherein said dispersion further contains oils.  
     
     
         16 . A method of producing core raw paper for corrugated boards coated with wax by using a paper machine provided with a plurality of driers wherein the dispersion containing wax is sprayed over the surface of heated driers in the area where the moisture content of core raw paper passing through the paper machine is less than 10%, the wax is changed into oil on the surface of the heated driers, the oil-changed wax is transferred from the surface of the driers onto the face of core raw paper so that the quantity of wax applied to core raw paper may be in a range of 0.1-10 mg/m 2 .  
     
     
         17 . A method of producing core raw paper for corrugated boards coated with wax by using a paper machine provided with a paper roll wherein the dispersion containing wax is sprayed over the surface of the paper roll, the wax is transferred onto the face of core raw paper with moisture content of less than 10% so that the quantity of wax applied to core raw paper may be in a range of 0.1-10 mg/m 2 .  
     
     
         18 . A wax or a dispersion containing wax applied on core raw paper for corrugating boards wherein the same is applied on core raw paper for corrugating boards described in  claim 3  or  4 .  
     
     
         19 . A wax or a dispersion containing wax used in the method for producing core raw paper for corrugating boards wherein the same is used in the method for producing core raw paper for corrugating boards described in  claim 5  or  9