Abrasive material

A method for producing an abrasive, comprising:

• forming a plurality of groups of agglomerate abrasive grains, each of said groups differing substantially from each of the other group or groups in the structural strength qualities, and therefore in the qualities of abrasive power and ability to sustain abrading forces, of the agglomerate grains thereof, wherein at least two of said groups of agglomerate grains are formed with different binding resins, said binding resins having compositions which are sufficiently different to obtain agglomerate abrasive grains of substantially different strength qualities, or wherein at least two of said groups of agglomerate grains are formed with individual abrasive grains of differing composition, said forming step of each of said groups comprising mixing individual abrasive grains with a binding resin, hardening, and breaking and separating into individual agglomerate grains of predetermined size;
• and
• binding said agglomerate grains in the presence of 0-70%, based on the weight of the agglomerate grains, of one or both of non-agglomerated abrasive grains and powdered, glassy carbon, to a carrier by means of a second binder.

A method in accordance with claim 12 or claim 14 wherein at least one of said groups of agglomerate grains are formed with the addition to said mixture of single abrasive grains and binding resin, of at least one additive selected from the group consisting of silicon release agents and powdered, glassy carbon, in an amount of up to 80%, based on the total weight of said binding resin and said additives.

A method for producing an abrasive, comprising:

• forming a plurality of groups of agglomerate abrasive grains, each of said groups differing substantially from each of the other group or groups in the structural strength qualities, and therefore in the qualities of abrasive power and ability to sustain abrading forces, of the agglomerate grains thereof, wherein at least two of said groups of agglomerate grains are formed using the same binding resin but using different hardening times therefor, and/or using differing quantities thereof, said hardening times or said quantities being sufficiently different to provide agglomerate abrasive grains of said substantially different strength qualities, wherein said forming step of each of said groups comprises mixing individual abrasive grains with a binding resin, hardening, and breaking and separating into individual agglomerate grains of predetermined size;
• and
• binding said agglomerate grains in the presence of 0-70%, based on the weight of the agglomerate grains, of one of both of non-agglomerated abrasive grains and powdered, glassy carbon, to a carrier by means of a second binder.