A method for producing a molded fibre product

Abstract

The present disclosure relates to a method of producing a molded fibre product, comprising the steps of: a) converting a dry pulp to a wet pulp having a consistency of 2-4 wt. %;b) diluting the wet pulp to obtain a diluted pulp having a consistency of 0.8-1.9 wt. %;c) storing the diluted pulp in a machine tank;d) diluting the diluted pulp from the machine tank to obtain a furnish having a consistency of 0.1-0.7 wt. %;e) storing the furnish in a circulation tank;f) feeding the furnish from the circulation tank to a forming tank; andg) forming the molded fibre product from the furnish in the forming tank.

1 . A method of producing a molded fibre product, comprising the steps of:
 a) converting a dry pulp to a wet pulp having a consistency of 2-4 wt. %;   b) diluting the wet pulp to obtain a diluted pulp having a consistency of 0.8-1.9 wt. %;   c) storing the diluted pulp in a machine tank;   d) diluting the diluted pulp from the machine tank to obtain a furnish having a consistency of 0.1-0.7 wt. %, such as 0.4-0.7 wt. %;   e) storing the furnish in a circulation tank;   f) feeding the furnish from the circulation tank to a forming tank; and   g) forming the molded fibre product from the furnish in the forming tank.   
     
     
         2 . The method of  claim 1 , wherein the step a) comprises the substeps of:
 a1) re-pulping the dried pulp in a pulper to obtain an intermediate pulp; and   a2) diluting the intermediate pulp to obtain the wet pulp.   
     
     
         3 . The method of  claim 2 , wherein step a2) comprises diluting the intermediate pulp with white water derived from step g). 
     
     
         4 . The method of  claim 2 , wherein step a1) comprises the substeps of:
 a1.1) preparation of a re-pulped pulp having a consistency of 5.0-7.0 wt. %; and   a1.2) diluting the re-pulped pulp to obtain the intermediate pulp.   
     
     
         5 . The method of  claim 4 , wherein the dilution of step a1.2) reduces the consistency by at least 25%. 
     
     
         6 . The method of  claim 4 , wherein step a1.2) comprises dilution of the re-pulped pulp with washing water that has been used to wash the pulper used to prepare the re-pulped pulp. 
     
     
         7 . The method of  claim 6 , wherein the washing water is obtained by washing the pulper with white water derived from step g). 
     
     
         8 . The method of  claim 1 , wherein the wet pulp prepared in step a) is stored in a storage tank before the dilution of step b). 
     
     
         9 . The method of  claim 1 , wherein step b) comprises dilution of the wet pulp with white water derived from step g). 
     
     
         10 . The method of  claim 1 , wherein step d) comprises dilution of the diluted pulp with white water derived from step g). 
     
     
         11 . The method of  claim 1 , wherein the diluted pulp has a consistency of 0.9-1.7 wt. %, such as 1.0-1.5 wt. %. 
     
     
         12 . The method of  claim 1 , wherein at least one chemical additive is added to the furnish in the circulation tank. 
     
     
         13 . The method of  claim 12 , wherein alkyl ketene dimer (AKD) is added to the furnish in the circulation tank. 
     
     
         14 . The method of  claim 1 , wherein the dry pulp used in step a) has a dry content of 80-95 wt. %, such as 84-92 wt. %. 
     
     
         15 . The method of  claim 1 , wherein the dry pulp used in step a) has Canadian Standard Freeness of 375-475 ml, preferably 400-450 ml, when measured according to ISO 5267/2-1980 after repulping according to ISO 5263-2:2204. 
     
     
         16 . The method of  claim 13 , wherein the alkyl ketene dimer (AKD) is added in an amount of 0.3-3 wt. % based on the dry weight of the fibre suspension. 
     
     
         17 . The method of  claim 1 , wherein white water from step g) is used in all dilution steps.