Glass structure strengthening by etching
AssigneeHughes Aircraft Company
InventorJohn P. Bagby
Life of this patent
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Abstract
A method of producing a superior quality of glass or other brittle material. The resulting end product is substantially stronger than conventional glass and exhibits greater strength consistency than was previously known. The techniques include various combinations of operations including substantially reducing the thickness of a blank of raw material; preparing formed edges including chamfered edges, rounded edges, and undercut edges; super polishing all edges and surfaces of a glass item; tempering the glass either thermally, chemically, or both; super polishing again after the tempering operation; and etching the glass after one or more of several steps in the process.
Claims15
A method for increasing the breaking stress of a glass plate wherein said glass plate includes a top surface, a bottom surface and at least one side surface, wherein each of said surfaces has a slope variance which is below about 10 microinches per inch of surface distance and wherein each of said surfaces has an rms surface roughness of below about 0.15 microinches, said method comprising the step of uniformly etching glass from each of said surfaces to provide an etched glass plate having an etched top surface, etched bottom surface and at least one etched side surface, wherein sufficient glass is uniformly removed from each of said glass plate surfaces so that each corresponding etched glass plate surface has a slope variance below about 10 microinches per inch of surface distance and an rms surface roughness of below about 0.15 microinches and wherein each of said etched glass plate surfaces is displaced inward to a depth in the range of between about at least 100 microinches to no more than 400 microinches.
Dependencies are inferred from the claim text.