Method of making resin bonded abrasive articles

Claim 1

A METHOD OF MAKING A MOLDED RESIN BONDED ABRASIVE ARTICLE WHICH COMPRISES MIXING ABRASIVE GRAINS WITH A SOLVENT FOR A HEAT-HARDENABLE SYNTHETIC RESIN, MIXING THE WETTED GRAINS WITH SUCH A HEAT-HARDENABLE RESIN IN POWDERED FORM UNTILL THE POWDERED RESIN BECOMES THOROUGHLY WETTED WITH THE SOLVENT AND FORMS COATINGS ABOUT THEE INDIVIDUAL GRAINS WHICH ARE ADHESIVE, THEN MIXING SUCH GRAINS WITH A POWDERED THEROMOPLASTIC RESIN WHICH IS INSOLUBLE IN THE SAID SOLVENT AND CONTINUING THE MIXING UNTIL THE INNER COATINGS PENETRATE THE POWDERED THERMOPLASTIC RESIN AND MAKE THE GRAINS SOMEWHAT STICKY, ADDING MORE OF THE SAID POWDERED HEAT-HARDENABLE RESIN IN A QUANTITY SUFFICIENT TO DRY UP THE COATINGS ON THE GRAINS AND PROVIDE A DISTRIBUTABLE MASS, PRESSING AN ARTICLE FROM THE MIXTURE IN A MOLD, AND HEATING THE ARTICLE TO HARDEN THE HEAT-HARDENABLE RESIN AND TO SOFTEN THE THERMOPLASTIC RESIN AND CAUSE A NUMBER OF PARTICLES OF SUCH POWDERED RESIN TO AGGLOMERATE AND BECOME DISTRIBUTED THROUGH THE MATRIX OF THE HEAT-HARDENED RESIN, THE SOFTENING POINT OF SAID THERMOPLASTIC RESIN BEING HIGH ENOUGH TO PREVENT THE RESIN FROM FLOWING THROUGH THE HEAT-HARDENABLE RESIN AND LOW ENOUGH SO THAT THE RESIN IS FLUXED AND A NUMBER OF PARTICLES OF THE RESIN CAN WELD TOGETHER AND FORM AGGREGATES.

Claim 2

A METHOD OF MAKING A MOLDED RESIN BONDED ABRASIVE ARTICLE WHICH COMPRISES MIXING ABRASIVE GRAINS WITH A SOLVENT FOR A HEAT-HARDENABLE SYNTHETIC RESIN, MIXING THE WETTED GRAINS WITH SUCH A HEAT-HARDENABLE RESIN IN POWDERED FORM UNTILL THE POWDERED RESIN BECOMES THOROUGHLY WETTED WITH THE SOLVENT AND FORMS COATINGS ABOUT THEE INDIVIDUAL GRAINS WHICH ARE ADHESIVE, THEN MIXING SUCH GRAINS WITH A POWDERED THEROMOPLASTIC RESIN WHICH IS INSOLUBLE IN THE SAID SOLVENT AND CONTINUING THE MIXING UNTIL THE INNER COATINGS PENETRATE THE POWDERED THERMOPLASTIC RESIN AND MAKE THE GRAINS SOMEWHAT STICKY, ADDING MORE OF THE SAID POWDERED HEAT-HARDENABLE RESIN IN A QUANTITY SUFFICIENT TO DRY UP THE COATINGS ON THE GRAINS AND PROVIDE A DISTRIBUTABLE MASS, PRESSING AN ARTICLE FROM THE MIXTURE IN A MOLD, AND HEATING THE ARTICLE TO HARDEN THE HEAT-HARDENABLE RESIN AND TO SOFTEN THE THERMOPLASTIC RESIN AND CAUSE A NUMBER OF PARTICLES OF SUCH POWDERED RESIN TO AGGLOMERATE AND BECOME DISTRIBUTED THROUGH THE MATRIX OF THE HEAT-HARDENED RESIN, THE SOFTENING POINT OF SAID THERMOPLASTIC RESIN BEING HIGH ENOUGH TO PREVENT THE RESIN FROM FLOWING THROUGH THE HEAT-HARDENABLE RESIN AND LOW ENOUGH SO THAT THE RESIN IS FLUXED AND A NUMBER OF PARTICLES OF THE RESIN CAN WELD TOGETHER AND FORM AGGREGATES.