摘要 |
Method and apparatus for etching light-sensitive photopolymerizable surfaces of printing plates. The apparatus includes a bath of etching fluid (32), a conveyor (38,40,42,52) for conveying printing plates (10) in a prescribed path (54), and transducers (46) mounted above the plates as they are conveyed within the bath and capable of forming longitudinal waves in the etching fluid at generally right angles to the surface of the printing plates. The invention is characterized by directing cleaning fluid between the acoustical radiating surface of the transducers (46) and the surface of the plates (10) in such a manner that the surface to be etched is swept with cleaning fluid of a sufficient velocity and volume as to prevent substantial cavitational erosion of the surface to be etched.
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