A cellulose paper composite and process for preparation thereof

Abstract

The present invention relates to a cellulose paper composite having enhanced ear propagation strength, ratio of tensile strength for cut and uncut paper, tensile strength and tensile modulus. The present invention further relates to a process for the preparation of cellulose paper composite having enhanced tensile strength and tensile modulus.

1 . A cellulose paper composite comprising 80-85% of micro-cellulose and 15-20% of nanocellulose, wherein the tear propagation resistance of the composite is increased by 50-70%. 
     
     
         2 . The cellulose paper composite as claimed in  claim 1 , wherein the the ratio (R) of tensile strength of sample with an existing cut or tear to the tensile strength of the sample without a cut is 75-95%. 
     
     
         3 . The cellulose paper composite as claimed in  claim 1 , wherein the increase in tensile modulus is 15-40%, and tensile strength by 30-50%, when compared to micro cellulose paper composite. 
     
     
         4 . A process for the preparation of cellulose paper composite as claimed in  claim 1 , wherein said process comprising the steps of:
 a) cutting the nanocellulose source material into small pieces;   b) subjecting the pieces of step (a) to alkali treatment by washing with base for 4 to 5 hours under mechanical stirring to form fibres;   c) subjecting the fibres of step (b) for bleaching treatment by using bleaching solution at temperature ranging from 70° C. to 80° C. for the time period ranging from 3 to 4 h; repeating process for 2 to 3 times to afford pulp;   d) filtering and rinsing the pulp of step (c) followed by grinding the pulp in ultra-fine micro grinder; and   e) combining the nanocellulose pulp prepared as per above steps (a-d) with microcellulose pulp in different compositions to make a composite paper.   
     
     
         5 . The process as claimed in  claim 4 , wherein said nanocellulose source material of step (a) is selected from cotton rag, sugarcane bagasse and sisal fibers. 
     
     
         6 . The process as claimed in  claim 4 , wherein said alkali treatment of step (b) is carried out by washing small pieces of nanocellulose source material with 1-10% base solution at 50 to 80° C. 
     
     
         7 . The process as claimed in  claim 4 , wherein said alkali treatment of step (b) is carried out by washing small pieces of nanocellulose source material with 1-10% sodium hydroxide solution at 50 to 80° C. 
     
     
         8 . The process as claimed in  claim 4 , wherein said bleaching solution of step (c) comprises 1:1 ratio of aqueous sodium hypochlorite (NaOCl in water) and an acetate buffer (NaOH and glacial acetic acid, diluted to 1 L using distilled water). 
     
     
         9 . The process as claimed in  claim 4 , wherein the fiber to liquor ratio is maintained 1:30 for both alkali and bleaching treatment.