Microfiber Reinforcement for Abrasive Tools

Abstract

An abrasive article includes an organic bond material, an abrasive material dispersed in the organic bond material, mineral wool microfibers uniformly dispersed in the organic bond material, the mineral wool microfibers being individual filaments, one or more reinforcement and / or chopped strand fibers dispersed in the organic bond material and one or more active fillers including, for example, a manganese compound. The abrasive article can be used in the abrasive processing of a workpiece.

Description

RELATED APPLICATIONS[0001]This application is a Continuation-in-Part of U.S. application Ser. No. 11 / 895,641 filed on Aug. 24, 2007, which claims the benefit under 35 USC 119(e) of U.S. Provisional Application No. 60 / 844,862, filed on Sep. 15, 2006, both of which are incorporated herein by reference in their entirety.BACKGROUND OF THE INVENTION[0002]Chopped strand fibers are used to reinforce resin-based grinding wheels. The chopped strand fibers typically 3-4 mm in length, are a plurality of filaments. The number of filaments can vary depending on the manufacturing process but typically consists of 400 to 6000 filaments per bundle. The filaments are held together by an adhesive known as a sizing, binder, or coating that should ultimately be compatible with the resin matrix. One example of a chopped strand fiber is referred to as 183 Cratec®, available from Owens Corning.[0003]Incorporation of chopped strand fibers into a dry grinding wheel mix is generally accomplished by blending ...

AI Technical Summary

Benefits of technology

[0006]One embodiment of the present invention provides a composition, comprising an organic bond material (e.g., thermosetting resin, thermoplastic resin, or rubber), an abrasive material dispersed in the organic bond material, and microfibers uniformly dispersed in the organic bond material. The microfibers are individual filaments and may include, for example, mineral wool fibers, slag wool fibers, rock wool fibers, stone wool fibers, glass fibers, and in particular milled glass fibers, ceramic fibers, milled basalt fibers, carbon fibers, aramid fibers, and polyamide fibers, and combinations thereof. The microfibers can have an average length, for example, of less than about 1000 μm. In one particular case, the microfibers have an average length in the range of about 100 to 500 μm and a diameter less than about 10 microns. In some embodiments, chopped strand fibers, e.g., fiberglass chopped strand fibers, are also present. In many instances the composition further includes one or more fillers with at least one being an active filler, capable of chemically reacting with the microfibers at the temperatures that occur during grinding. These chemical reactions of the active filler and microfibers provide various abrasive process benefits (e.g., improved wheel life, higher G-ratio, and / or anti-loading of abrasive tool face). Examples of suitable active fillers include manganese compounds, silver compounds, boron compounds, phosphorous compounds, and combinations thereof. In one specific such case, the one or more active fillers include manganese dichloride. Other fillers that do not chemically react with the microfibers may also be incorporated.

[0012]Aspects of the invention provide compositions in the form of abrasive articles such as, for example, grinding wheels or other bonded abrasive tools that exhibit improved strength (as reflected, e.g., by the burst speed characterizing the tool) and impact resistance, with tools according to embodiments of the invention being robust and less prone to breakage. Abrasive articles according to embodiments of the invention also display improved wheel wear rate, G-ratio and a longer tool life. Examples of the bonded articles disclosed herein can exhibit good thermal shock resistance with little or no thermal cracking being observed. Abrasive articles that contain glass web reinforcements, and, optionally, chopped strand fibers, typically display improved impact properties.

Problems solved by technology

In any such cases, chopped strand fiber reinforced wheels typically suffer from a number of problems, including lower strength, poor grinding performance as well as inadequate wheel life, presumably due to incomplete dispersal of the filaments within the chopped strand fiber bundle.

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