Extremely fine abrasive particles are incorporated in an elastomeric resin body or coating to produce abrasive articles exhibiting cushioned or resilient yielding qualities having a dual response to in-service conditions. These performance characteristics are accomplished by a structure whose working surface and underlying supporting means produce two distinct and complementary abrading actions, one hard enough to sharpen a hardened cutting tool and to smooth the adjacent surface, and a second of being virtually simultaneously micro-deformable, via the mechanisms of cold flow, at or near maximum or optimum sharpening pressure. Such abrasive articles allow limited local displacement of a volume of the abrasive surface layer in a continuous wave to lift the surface at the tool edge to a height slightly beyond the plane of the edge being sharpened to "wipe" and so refine the extreme edge of the cutting tool and to remove the "wire-edge" as only athree-dimensional form of contact will accomplish. The articles of this invention are particularly suited to the performance of honing, stropping and lapping operations.
A rotary surface finishing tool includes a generally circular body of a finishing material, such as polymeric foam, the peripheral edge of which is wrapped around the outer edge of a circular cup-shaped backing plate. The plate is subsequently crimped over the edge of a locking ring to capture the edge of the foam material therebetween. Other types of finishing material, such as tufted wool, including a backing with a flexible peripheral edge can also be mounted to a backing plate using the crimping techniques described herein.
A rotary trowel (1) for use in the molding of ceramics (15) comprising a trowel matrix (2) and a trowel surface (3) provided on said trowel matrix (2) so as to make contact with a raw clay composition (15) and calender the raw clay composition (15), characterized in that said trowel surface (3) is formed by providing an epoxy resin composition containing an abrasion-resistant material on the inner surface of a casting mold (6).
A method of forming abrasive grinding wheels includes the steps of preheating abrasive grains, an open circular mold and liquid epoxy binder, to a temperature below the curing temperature of the binder and at which the binder has relatively low viscosity. The binder is placed in the mold and the mold is rotated. As the mold is rotated the abrasive is added along a radian with respect to an axis of rotation of the mold. The rate of the addition of the abrasive grains and the rotational speed of the mold are controlled such that abrasive grains added during a prior rotation submerge in the binder by the time the mold again reaches the radian where more grains are added. After the binder is suitably filled with abrasive, the wheel is cured by heating and the solid mass removed from the mold and trimmed to size, removing any skin of excess binder. The method produces grinding wheels having low porosity, excellent balance and grinding characteristics. The method is suitable for use in the manufacture of super abrasive wheels as well as wheels which include conventional abrasives and fillers.
A method of forming abrasive grinding wheels includes the steps of preheating abrasive grains, an open circular mold and liquid epoxy binder, to a temperature below the curing temperature of the binder and at which the binder has relatively low viscosity. The binder is placed in the mold and the mold is rotated, or the mold is held stationary and grains are added from a moving delivery source. The abrasive is added along a radian with respect to an axis of the mold. The rate of the addition of the abrasive grains and the rotational speed of the mold or delivery source are controlled such that abrasive grains added during a prior rotation submerge in the binder by the time the mold or delivery source again reaches the area where more grains are added. After the binder is suitably filled with abrasive, the wheel is cured by heating and the solid mass removed from the mold and trimmed to size, removing any skin of excess binder. The method produces grinding wheels having low porosity, excellent balance and grinding characteristics. The method is suitable for use in the manufacture of super abrasive wheels as well as wheels which include conventional abrasives and fillers.
Solder interconnection whereby the gap created by solder connections between a carrier substrate and semiconductor device is filled with a composition obtained from curing a preparation containing a cycloaliphatic polyepoxide and/or curable cyanate ester or prepolymer thereof; filler having a maximum particle size of 31 microns and being at least substantially free of alpha particle emissions.
