The grinding media is formed of a concentration of agglomerate free hard particles exceeding 50 percent by weight of the media, wherein the particles are chelated by a dispersing agent, surface treated with a surfactant, mixed with polyether polyol and polyisocyanate plus a catalyst and water and thereafter rapidly cured in a closed mold which has been preheated to a temperature exceeding 50.degree. C. and a pressure of 60 to 120 PSIG. The water reacts during curing to create a polyurea linkage and release CO.sub.2 as a blowing agent. The resulting media has a low elastic modulus with particles retained in a polyurethane-urea binder system. The media composition may also include an inorganic filler such as glass fibers not exceeding 30 percent by weight of the media.
Methods are disclosed for making abrasive articles including decorative patterns. In one embodiment, the method includes printing inks or dyes onto an upper surface of a foam sheet to create a decorative pattern thereon, and bonding abrasive material over the decorative pattern, the abrasive material being translucent or transparent such that the decorative pattern is visible through the abrasive material. In another embodiment, the method includes providing a base layer, mixing abrasive material with binder material, one or more pigments, and a blowing agent, applying the first mixture to one or more regions of an upper surface of the base layer in a predetermined pattern, and curing the first abrasive mixture such that the blowing agent is activated to create an expanded abrasive layer on the upper surface of the base layer that has a thickness greater than adjacent regions of the upper surface.
Grinding wheels are constructed with an improved type of resin binder of a low molecular weight solid epoxy resin. The epoxy resin is in the form of a fine powder and may be mixed with other wheel components such as abrasive grain, wetting agent and fillers. A method in which the epoxy resin and curing agents are processed from their commercially available forms to that most suitable for use as a grinding wheel binder.
A product and process for reconditioning abrasive stones used to sharpen metal tools such as woodworking tools. The product is a slab made up of abrasive grain bond with an organic polymer.
An abrasive composition and dental articles made from same, the composition including abrasive particles dispersed throughout and entrapped within a polyurea or polyurethane urea matrix which contains soft and hard segments wherein the matrix is made from the polymerization reaction of a polyfunctional amine and a polyfunctional isocyanate. The abrasive dental articles include prophylactic cups and polishing wheels, points and discs.
The present invention relates to a polishing method using a grindstone comprising abrasive grains and a bonding resin for bonding the abrasive grains, as well as to a polishing apparatus to be used for the polishing method. By using a resin for bonding abrasive grains, it is possible to obtain a grindstone having a desired modulus of elasticity. With such a grindstone, the surface of a substrate having concave and convex portions can be rendered uniformly flat, irrespective of the size of the concave and convex portions. Further, by first polishing the substrate surface with a polishing tool of a small elastic modulus and thereafter polishing it with a polishing tool of a large elastic modulus, it is possible to obtain a polished surface of reduced damage. The method of the invention is effective in planarizing various substrate surfaces having concave and convex portions.
