Manipulation of magnetizable abrasive particles with modulation of magnetic field angle or strength

Abstract

According to one embodiment, a method of making an abrasive article is disclosed. The method can comprise: disposing a layer of a curable composition into a mold having a circular mold cavity with a central hub, wherein the circular mold cavity has an outer circumference and a rotational axis extending through the central hub, and wherein the curable composition is comprised of at least some magnetizable abrasive particles dispersed therein; and varying a magnetic field relative to the curable composition such that a majority of the magnetizable abrasive particles are at least one of oriented and aligned in a non-random manner relative to a surface of the mold; and at least partially curing the curable composition to provide the bonded abrasive article.

The claimed invention is: 
     
         1 . A method of making a bonded abrasive article, the method comprising:
 disposing a layer of a curable composition into a mold having a circular mold cavity with a central hub, wherein the circular mold cavity has an outer circumference and a rotational axis extending through the central hub, and wherein the curable composition is comprised of at least some magnetizable abrasive particles dispersed therein; and   varying a magnetic field relative to the curable composition such that a majority of the magnetizable abrasive particles are at least one of oriented and aligned in a non-random manner relative to a surface of the mold; and   at least partially curing the curable composition to provide the bonded abrasive article.   
     
     
         2 . The method of  claim 1 , wherein the bonded abrasive article comprises one of a vitrified bonded article and a resin bonded article. 
     
     
         3 . The method of  claim 1 , wherein the bonded abrasive article includes one or more layers, and wherein at least one of the layers is formed of a curable composition, the curable composition formed by at least some of the magnetizable abrasive particles. 
     
     
         4 . The method of  claim 3 , wherein the bonded abrasive article has reinforcing material. 
     
     
         5 . The method of  claim 1 , further comprising:
 varying a magnetic field relative to the curable composition such that a majority of the magnetizable abrasive particles are at least one of oriented and aligned in a non-random manner relative to the surface of the mold; and   at least partially curing the curable composition to provide the bonded abrasive article.   
     
     
         6 . The method of  claim 5 , wherein the surface of the mold comprises disc-shaped bottom surface and wherein varying the magnetic field relative to the magnetizable abrasive particles comprises disposing at least a first magnet spaced from the magnetizable abrasive particles and the bottom surface. 
     
     
         7 . The method of  claim 1 , wherein varying the magnetic field relative to the magnetizable abrasive particles comprises at least one of: varying a strength of the magnetic field produced by the first magnet, oscillating along a diameter of the mold along a first axis with the poles of the magnet maintained aligned with a second axis, oscillating the first magnet linearly along a diameter of the disc-shaped bottom surface along the first axis with the poles of the magnet maintained aligned with the first axis, rotating the first magnet about an axis at a center of the mold, pivoting the first magnet about an axis at a center of the disc-shaped bottom surface, translating the first magnet linearly along a diameter of the mold along the first axis with the poles of the magnet rotated about a third axis, oscillating the first magnet linearly along a diameter of the mold along the first axis with the poles of the magnet rotated about a third axis, and oscillating the first magnet linearly along a diameter of the disc-shaped bottom surface along the first axis with the poles of the magnet alternated along the third axis. 
     
     
         8 . The method of  claim 1 , wherein the magnetizable abrasive particles are shaped abrasive particles. 
     
     
         9 . The method of  claim 8 , wherein the shaped abrasive particles comprise triangular platelets. 
     
     
         10 . The method of  claim 8 , wherein the shaped abrasive particles comprise rods. 
     
     
         11 . A method of making a non-woven abrasive article, the method comprising:
 providing a non-woven backing;   disposing magnetizable abrasive particles on the backing;   varying a magnetic field relative to the magnetizable abrasive particles to impart at least one of a non-random orientation and alignment of the magnetizable abrasive particles relative to the backing.   
     
     
         12 . The method of  claim 11 , wherein the magnetizable abrasive particles comprise a shaped body. 
     
     
         13 . The method of  claim 12 , wherein the shaped body comprises at least one of a triangular platelet and a rod. 
     
     
         14 . The method of  claim 11 , further comprising dispensing the magnetizable abrasive particles on the backing up-web of the magnetic field. 
     
     
         15 . The method of  claim 11 , wherein varying the magnetic field relative to the magnetizable abrasive particles comprises disposing at least a first magnet adjacent one of the first major surface or a second opposing major surface of the backing. 
     
     
         16 . The method of  claim 15 , further comprising disposing at least a second magnet adjacent the second major surface of the backing.