Houghton International Inc. and Houghton Technical Corp. announced that the United States Patent Office issued U.S. Patent No. 9,732,428, “Methods and Compositions for Acid Treatment of a Metal Surface.” This patent protects Houghton’s technology for aluminum acid etching, which improves upon conventional caustic etching and is formulated to provide a premium matte finish at low gloss values with minimum aluminum dissolution. 

Compared to conventional caustic etching, Houghton’s acid etch technology significantly reduces etch time, reduces waste sludge by over 50% and is performed at lower temperatures. For aluminum extrusion customers, the technology is effective in hiding extrusion lines and is not sensitive to zinc contamination.