Pulp composition

Abstract

One aspect of the invention relates to a pulp composition made from agricultural renewable fibers (ARF) having low Kappa number with unexpected quality sufficient for papermaking (e.g., high strength parameters and high freeness). Another aspect of the invention relates to an ARF pulp having ISO brightness of 60% or higher, and unexpected quality sufficient for papermaking (e.g. high strength parameters and high freeness). Another aspect of the invention relates to a pulp composition made from a pulping process comprising using a high concentration of anthraquinone (AQ). The pulping process can use wood or nonwood fibers (e.g., bagasse and corn stover) to provide pulp having good paper-making quality.

1 . A pulp composition comprising:
 fibers from an agricultural renewable fiber source, wherein the pulp composition has an unbleached Kappa number of about 20 or less, a high freeness of at least about 400 mL CSF, and a tensile of at least about 5.50 km, a tear index of at least about 6.00 mN·m 2 /g, and a burst index of at least about 3.00 kPa·m 2 /g.   
     
     
         2 . The pulp composition of  claim 1 , wherein the Kappa number is about 19 or less. 
     
     
         3 . The pulp composition of  claim 1 , wherein the Kappa number is about 18 or less. 
     
     
         4 . The pulp composition of  claim 1 , wherein the Kappa number is about 15 or less. 
     
     
         5 . The pulp composition of  claim 1 , wherein the agricultural renewable fiber source is bagasse, corn stover, wheat straw, cereal straws, rice straw, soy residuals, coconut tissues, cotton stalks, palm baskets, kenaf, industrial hemp, seed flax straw, textile flax straw, sisal, hesperaloe, rye grass, or combinations thereof. 
     
     
         6 . The pulp composition of  claim 5 , wherein the agricultural renewable fiber source is bagasse, corn stover, wheat straw, cereal straws, rice straw, soy residuals, coconut tissues, cotton stalks, palm baskets, kenaf, industrial hemp, seed flax straw, textile flax straw, sisal, hesperaloe, rye grass, or combinations thereof. 
     
     
         7 . A pulp composition comprising fibers from an agricultural renewable fiber (ARF) source, wherein the pulp composition has an unbleached Kappa number of about 20 or less, a high freeness of at least about 400 mL CSF, and strength parameters sufficient for papermaking. 
     
     
         8 . The pulp composition of  claim 7 , wherein the ISO brightness is less than 50% ISO. 
     
     
         9 . The pulp composition of  claim 7 , wherein the ARFs are bagasse, corn stover, wheat straw, cereal straws, rice straw, soy residuals, coconut tissues, cotton stalks, palm baskets, kenaf, industrial hemp, seed flax straw, textile flax straw, sisal, hesperaloe, rye grass, or combinations thereof. 
     
     
         10 . A pulp composition made from a pulping method comprising:
 providing a first mixture comprising the reaction products of:
 fibers, 
 water, 
 anthraquinone or derivative thereof having concentration of about 0.1% by weight or greater of the dry fiber, and 
 an alkali, 
 wherein the mixture has a liquid to dry fiber ratio from about 4 to about 10, and an initial Kappa number of about 60 or greater; and 
   reacting the mixture for a cooking time and at a cooking condition sufficient to form a second mixture having a Kappa number of about 20 or less, high freeness of at least about 400 mL CSF, and strength parameters sufficient for papermaking.   
     
     
         11 . The pulp composition of  claim 10 , wherein the strength parameters sufficient for papermaking are selected from the group consisting of a tensile of at least about 5.50 km, a tear index of at least about 6.00 mN·m 2 /g, a burst index of at least about 3.00 kPa·m 2 /g, or a combination thereof. 
     
     
         12 . The pulp composition of  claim 10 , wherein the cooking condition and cooking time provides an H-factor of about 200 or higher. 
     
     
         13 . The pulp composition of  claim 10 , wherein the second mixture has a Kappa number of about 19 or less. 
     
     
         14 . The pulp composition of  claim 10 , wherein the second mixture has a Kappa number of about 18 or less. 
     
     
         15 . The pulp composition of  claim 10 , wherein the second mixture has a Kappa number of about 15 or less. 
     
     
         16 . The pulp composition of  claim 10 , wherein the second mixture has a Kappa number of about 10 or less. 
     
     
         17 . The pulp composition of  claim 10 , wherein the fibers comprise agricultural renewable fibers. 
     
     
         18 . The pulp composition of  claim 10 , wherein the fibers comprise wood fibers. 
     
     
         19 . The pulp composition of  claim 10 , wherein the pulping method further comprises bleaching the second mixture. 
     
     
         20 . The pulp composition of  claim 19 , wherein the pulp has an ISO brightness of less than 50%.