Abrasive disc with vitrified agglomerate islands

A process for using vitrified abrasive materials to produce abrasive island discs comprising:

• a providing a polymer or metal circular backing substrate having a backing substrate top surface, a backing substrate bottom surface, a backing substrate diameter and a backing substrate thickness;
• b) providing a mixture of abrasive particles and a glass frit material and heating the mixture to a temperature sufficient to melt the glass frit material thereby encapsulating the abrasive particles in a glass matrix thereby forming an abrasive and glass matrix material, cooling the abrasive and glass matrix material, and fracturing the solidified vitrified abrasive and glass matrix material into vitrified abrasive agglomerates;
• c) providing a mixture of the vitrified abrasive agglomerates and an island adhesive and molding the mixture of the vitrified abrasive agglomerates and the island adhesive into abrasive island structures and solidifying the island adhesive wherein the island adhesive bonds the abrasive island structures to the backing substrate top surface;
• d) forming the abrasive island structures to have abrasive island structure shapes, abrasive island structure sizes, abrasive island structure thicknesses and abrasive island structure flat top surfaces;
• e) bonding the abrasive island structures to the backing substrate in an array pattern band having an array pattern band substantially annular shape, an array pattern band substantially annular outer diameter, an array pattern band substantially annular inner diameter and wherein gap spaces exist between adjacent abrasive island structures;
• f) providing a porous island gap space erodible material that is attached to the backing substrate top surface in the gap spaces between adjacent abrasive island structures wherein the porous island gap space erodible material has a top surface that is level with the abrasive island structures flat top surfaces.