Methods of making composites comprising superabsorbent materials having a bimodal particle size distribution

Abstract

The present invention is directed to a method of making an absorbent composite containing superabsorbent material. The method includes incorporating a superabsorbent material comprising superabsorbent particles into a substrate, wherein the superabsorbent particles have a bimodal particle size distribution. The absorbent composite displays enhanced fluid intake and fluid distribution properties, and is useful in disposable personal care products.

What is claimed is:  
     
         1 . A method of making an absorbent composite comprising: 
 incorporating a superabsorbent material comprising superabsorbent particles into a substrate, wherein the superabsorbent particles have a bimodal particle size distribution with large particles having a mass median particle size from about 850 to about 1800 microns and small particles having a mass median size from about 50 to about 200 microns.    
     
     
         2 . The method of  claim 1 , wherein the large particles have a mass median size from about 1000 to about 1600 microns.  
     
     
         3 . The method of  claim 1 , wherein the small particles have a mass median size from about 65 to about 150 microns.  
     
     
         4 . The method of  claim 1 , wherein the superabsorbent particles have an overall mass median particle size of about 60 to about 1750 microns.  
     
     
         5 . The method of  claim 1 , wherein the mass ratio of large particles to small particles is from about 90:10 to about 50:50.  
     
     
         6 . The method of  claim 1 , wherein the mass ratio of large particles to small particles is from about 90:10 to about 80:20.  
     
     
         7 . The method of  claim 1 , wherein the superabsorbent material is uniformly distributed within the composite.  
     
     
         8 . The method of  claim 1 , wherein the absorbent composite comprises from about 20% to about 100% by weight superabsorbent material.  
     
     
         9 . The method of  claim 1 , wherein the absorbent composite comprises from about 30% to about 90% by weight superabsorbent material.  
     
     
         10 . The method of  claim 1 , wherein the substrate comprises fibrous material.  
     
     
         11 . The method of  claim 10 , wherein the substrate is a woven or nonwoven fabric.  
     
     
         12 . The method of  claim 1 , wherein the superabsorbent material is incorporated into the substrate as a solid particulate material.  
     
     
         13 . A method of making an absorbent composite comprising: 
 incorporating a superabsorbent material into a substrate, wherein the superabsorbent material is uniformly distributed within the composite, and wherein the composite has a third liquid insult intake time less than about 100 seconds and a third intermittent vertical wicking pickup time less than about 600 seconds.    
     
     
         14 . The method of  claim 13 , wherein the absorbent composite has a third liquid insult intake time less than about 85 seconds.  
     
     
         15 . The method of  claim 13 , wherein the absorbent composite has a third liquid insult intake time less than about 60 seconds.  
     
     
         16 . The method of  claim 13 , wherein the absorbent composite has a third intermittent vertical wicking pickup time of less than about 300 seconds.  
     
     
         17 . The method of  claim 13 , wherein the absorbent composite comprises from about 20% to about 100% by weight superabsorbent material.  
     
     
         18 . The method of  claim 13 , wherein the absorbent composite comprises from about 30% to about 90% by weight superabsorbent material.  
     
     
         19 . The method of  claim 13 , wherein the superabsorbent material comprises superabsorbent particles having a bimodal particle size distribution.  
     
     
         20 . The method of  claim 19 , wherein the superabsorbent particles comprise large particles having a mass median size from about 1000 to about 1600 microns.  
     
     
         21 . The method of  claim 19 , wherein superabsorbent particles comprise small particles having a mass median size from about 65 to about 150 microns.  
     
     
         22 . The method of  claim 20 , wherein the superabsorbent particles have an overall mass median particle size of about 60 to about 1750 microns.  
     
     
         23 . The method of  claim 19 , wherein the superabsorbent particles comprise large particles and small particles, and wherein the mass ratio of large particles to small particles is from about 90:10 to about 50:50.  
     
     
         24 . The method of  claim 19 , wherein the superabsorbent particles comprises large particles and small particles, and wherein the mass ratio of large particles to small particles is from about 90:10 to about 80:20.  
     
     
         25 . The method of  claim 13 , wherein the substrate comprises fibrous material.  
     
     
         26 . The method of  claim 25 , wherein the substrate is a woven or nonwoven fabric.  
     
     
         27 . The method of  claim 13 , wherein the superabsorbent material is incorporated into the substrate as a solid particulate material.  
     
     
         28 . A method of making an absorbent composite comprising: 
 mixing a fibrous material with superabsorbent material comprising superabsorbent particles, wherein the superabsorbent particles have a bimodal particle size distribution with large particles having a mass median particle size from about 850 to about 1800 microns and small particles having a mass median size from about 50 to about 200 microns.    
     
     
         29 . The method of  claim 28 , wherein the superabsorbent material and the fibrous material are mixed by an air forming process.  
     
     
         30 . The method of  claim 28 , wherein the large particles have a mass median size from about 1000 to about 1600 microns.  
     
     
         31 . The method of  claim 28 , wherein the small particles have a mass median size from about 65 to about 150 microns.  
     
     
         32 . The method of  claim 28 , wherein the superabsorbent particles have an overall mass median particle size of about 60 to about 1750 microns.  
     
     
         33 . The method of  claim 28 , wherein the mass ratio of large particles to small particles is from about 90:10 to about 50:50.  
     
     
         34 . The method of  claim 28 , wherein the mass ratio of large particles to small particles is from about 90:10 to about 80:20.  
     
     
         35 . The method of  claim 28 , wherein the superabsorbent material is uniformly distributed within the composite.  
     
     
         36 . The method of  claim 28 , wherein the absorbent composite comprises from about 20% to about 100% by weight superabsorbent material.  
     
     
         37 . The method of  claim 28 , wherein the absorbent composite comprises from about 30% to about 90% by weight superabsorbent material.  
     
     
         38 . A method of making an absorbent composite comprising: 
 mixing a fibrous material with superabsorbent material, wherein the superabsorbent material is uniformly distributed within the composite, and wherein the composite has a third liquid insult intake time less than about 100 seconds and a third intermittent vertical wicking pickup time less than about 600 seconds.    
     
     
         39 . The method of  claim 38 , wherein the absorbent composite has a third liquid insult intake time less than about 85 seconds.  
     
     
         40 . The method of  claim 38 , wherein the absorbent composite has a third liquid insult intake time less than about 60 seconds.  
     
     
         41 . The method of  claim 38 , wherein the absorbent composite has a third intermittent vertical wicking pickup time of less than about 300 seconds.  
     
     
         42 . The method of  claim 38 , wherein the superabsorbent material and the fibrous material are mixed by an air forming process.  
     
     
         43 . The method of  claim 38 , wherein the absorbent composite comprises from about 20% to about 100% by weight superabsorbent material.  
     
     
         44 . The method of  claim 38 , wherein the absorbent composite comprises from about 30% to about 90% by weight superabsorbent material.  
     
     
         45 . The method of  claim 38 , wherein the superabsorbent material comprises superabsorbent particles having a bimodal particle size distribution.  
     
     
         46 . The method of  claim 45 , wherein the superabsorbent particles comprise large particles having a mass median size from about 850 to about 1600 microns.  
     
     
         47 . The method of  claim 45 , wherein superabsorbent particles comprise small particles having a mass median size from about 65 to about 150 microns.  
     
     
         48 . The method of  claim 45 , wherein the superabsorbent particles have an overall mass median particle size of about 60 to about 1750 microns.  
     
     
         49 . The method of  claim 45 , wherein the superabsorbent particles comprise large particles and small particles, and wherein the mass ratio of large particles to small particles is from about 90:10 to about 50:50.  
     
     
         50 . The method of  claim 45 , wherein the superabsorbent particles comprises large particles and small particles, and wherein the mass ratio of large particles to small particles is from about 90:10 to about 80:20.