Appliance Design - April 2009 - (Page 35) DECORATION as stone or marble, would also be possible, though they have not yet been attempted. While the methods for duplicating a natural texture are as diverse as the textures that occur in nature itself, the following describes the process for translating a texture to a metal foil. First, a specimen must be chosen and its surface prepared. Then the specimen’s texture is nano-imprinted on a polymer sheet for the fabrication of a negative mold. The surface of the negative mold is then metalized for the electroforming of a positive metallic mold. The positive mold is used to make multiple negative master mold modules. The negative master mold modules are integrated into a negative grand master mold, which serves as an electrode in the production-level electroforming process. A metallic deposit is electroformed on a foil form on the electrode immersed in the bath. The textured metal foil is then separated from the electrode and rolled out of the bath. The foil is then cleansed, dried, colorized, cut at a certain interval, and then packaged into rolls. The colorization is done either by paint spray or by vapor deposition depending on the fineness of the texture. A protective epoxy coating is sometimes add- Item Coating thickness Cross cut test Pencil hardness Chemical resistance Boiling water test pH resistance Salt spray test Cosmetic resistance RCA Test Condition Under 30um No detachment Min. 2H 500g/50cycles 90˚C±1˚C/ 30mins pH4.5/48hrs 5% NaCl/72hrs 80˚C, 80%/24hrs SPF30 NiveaSun Spray 275g/20 cycles Under 30um No detachment Min. 2H No detachment Criterion No detachment/No corrosion/No discoloration No swelling/ No detachment/No corrosion/No discoloration No swelling/ No detachment/No corrosion/No discoloration No swelling/ No detachment/No corrosion/No discoloration No appearance of base materials Fig. 1. Some preliminary test results regarding the durability of the nanoscale translated texture. ed at the very final step if needed to meet objectives or specifications. The negative grand master mold in this patented process takes a cylinder form and rolls slowly in the bath for the continuous electroforming of a textured foil. The foil thickness may vary depending on the application. For electronic housing frames, for example, a typical thickness of the foil is about 100 micrometers. Production costs are lower for a lesser thickness. With the establishment of mass production facilities in the near future, it’s expected that the current production cost will be reduced by half. So far, application of the technology has been somewhat restricted to the manufacture The Perfect Finishing Touch AD12084Doug.indd 1 www.applianceDESIGN.com • Chrome, gold & platinum plated nameplates • Painted, hot stamped & pad printed nameplates • Metalized 2nd surface nameplate assemblies • Decorative trim • Injection molded bezels & faceplates • Polyurethane urocals • Decals • Individual letter three dimensional graphics • Flexible graphics • Graphic overlays & membrane switches 9650 Valley View Road Eden Prairie, MN 55344 800-806-6113 • douglascorp.com 11/12/08 2009 35 applianceDESIGN April 10:27:32 AM http://www.douglascorp.com http://www.douglascorp.com http://www.appliancedesign.com
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