Nonwoven abrasive articles and methods of making the same

Abstract

A nonwoven abrasive article comprises a lofty open nonwoven fiber web comprising entangled fibers. The fibers have an average diameter, and the fiber web has first and second opposed major surfaces and a porous interior therebetween. An abrasive material is predominantly disposed within the porous interior. The abrasive material comprises abrasive particles at least partially retained in a binder. The abrasive material comprises elongated blobs. Each elongated blob is respectively bonded to at least one of the fibers. The elongated blobs have a minimum width of at least two times the average diameter of the fibers, wherein a majority of the elongated blobs are longitudinally aligned within 40 degrees. The abrasive particles are magnetizable, the elongated blobs further comprise magnetizable particles different from the abrasive particles, or both. Methods of making the nonwoven abrasive article are also disclosed.

1 . A nonwoven abrasive article comprising:
 a lofty open nonwoven fiber web comprising entangled fibers, wherein the fibers have an average diameter, and wherein the lofty open nonwoven fiber web has first and second opposed major surfaces and a porous interior therebetween; and   an abrasive material predominantly disposed within the porous interior of the lofty open fiber web, wherein the abrasive material comprises abrasive particles at least partially retained in a binder, wherein the abrasive material comprises elongated blobs, wherein each one of the elongated blobs is respectively bonded to at least one of the fibers, wherein the elongated blobs have a minimum width of at least two times the average diameter of the fibers, wherein a majority of the elongated blobs are longitudinally aligned within 40 degrees, and further wherein:   i) the abrasive particles are magnetizable; or   ii) the elongated blobs further comprise magnetizable particles different from the abrasive particles; or   iii) both i) and ii).   
     
     
         2 . The nonwoven abrasive article of  claim 1 , wherein the elongated blobs collectively occupy at least 20 volume percent of the porous interior. 
     
     
         3 . (canceled) 
     
     
         4 . The nonwoven abrasive article of  claim 1 , wherein the abrasive particles comprise at least one of abrasive rods, shaped abrasive platelets, or crushed abrasive particles conforming to an abrasives industry specified nominal grade. 
     
     
         5 . (canceled) 
     
     
         6 . The nonwoven abrasive article of  claim 1 , wherein the abrasive particles comprise a material having a Mohs scale hardness of at least 8. 
     
     
         7 . The nonwoven abrasive article of  claim 1 , wherein the abrasive particles are magnetizable. 
     
     
         8 . The nonwoven abrasive article of  claim 1 , wherein the elongated blobs comprise the magnetizable particles different from the abrasive particles. 
     
     
         9 . The nonwoven abrasive article of  claim 1 , wherein a majority of the elongated blobs extend at least between the first and second opposed major surfaces. 
     
     
         10 . The nonwoven abrasive article of  claim 1 , wherein the elongated blobs have longitudinally oriented sides that are aligned within 20 degrees of being parallel to a thickness dimension of the lofty open fiber web. 
     
     
         11 . The nonwoven abrasive article of  claim 1 , wherein a majority of the elongated blobs have an aspect ratio of at least 5:1. 
     
     
         12 . The nonwoven abrasive article of  claim 1 , wherein the magnetizable particles comprise ferromagnetic material. 
     
     
         13 . The nonwoven abrasive article of  claim 1 , wherein the abrasive particles comprise alpha alumina, zirconia, silicon carbide, or a combination thereof. 
     
     
         14 . The nonwoven abrasive article of  claim 1 , wherein at least some of the elongated blobs extend beyond at least one of the first or second major surfaces. 
     
     
         15 . A method of making a nonwoven abrasive article, the method comprising the steps:
 a) providing a lofty open nonwoven fiber web comprising entangled fibers, wherein the fibers have an average diameter, and wherein the lofty open nonwoven fiber web has first and second opposed major surfaces and a porous interior therebetween;   b) disposing a mixture comprising a curable binder precursor and magnetizable particles predominantly into a portion of the porous interior;   c) applying a magnetic field to the mixture;   d) disposing abrasive particles onto the mixture; and   e) at least partially curing the curable binder precursor to form an abrasive material predominantly disposed within the porous interior of the lofty open fiber web, wherein the abrasive material comprises the abrasive particles and magnetizable at least partially retained in a binder material, wherein the abrasive material comprises elongated blobs, wherein each one of the elongated blobs is respectively bonded to at least one of the fibers, wherein the elongated blobs have a minimum width of at least two times the average diameter of the fibers, wherein a majority of the elongated blobs are longitudinally aligned within 40 degrees.   
     
     
         16 . The method of  claim 15 , wherein the magnetic field is an oscillating magnetic field. 
     
     
         17 . A method of making a nonwoven abrasive article, the method comprising the steps:
 a) providing a lofty open nonwoven fiber web comprising entangled fibers, wherein the fibers have an average diameter, and wherein the lofty open nonwoven fiber web has first and second opposed major surfaces and a porous interior therebetween;   b) disposing an abrasive material precursor predominantly into a portion of the porous interior, and wherein the abrasive material precursor comprises a curable binder precursor, abrasive particles, and magnetizable particles;   c) applying a magnetic field to the abrasive material precursor; and   d) at least partially curing the curable binder precursor to form an abrasive material predominantly disposed within the porous interior of the lofty open fiber web, wherein the abrasive material comprises the abrasive particles and the magnetizable particles at least partially retained in a binder material, wherein the abrasive material comprises elongated blobs, wherein each one of the elongated blobs is respectively bonded to at least one of the fibers, wherein the elongated blobs have a minimum width of at least two times the average diameter of the fibers, wherein a majority of the elongated blobs are longitudinally aligned within 40 degrees.   
     
     
         18 . The method of  claim 15 , wherein the magnetic field is an oscillating magnetic field. 
     
     
         19 . The method of  claim 15 , wherein steps b) and c) are sequential. 
     
     
         20 - 22 . (canceled)