Decorating plating

To make a decorated plate, the mold is opened shortly after the main charge of molding compound has been pressed iato shape, the decorative foil is laid ia the mold on top of the partially cured plate, ptinted side down, and the mold closed again to complete the curing process. The melamiae-treated foil is thus fused to the molded plate and, as with the decorative lamiaate, the overlay becomes transparent so that the ptinted design shows through yet is protected by the film of cured resia. 

Electroplating. Chromium is electroplated onto various substrates in order to realize a more decorative and corrosion- or wear-resistant surface (24—32). About 80% of the chromium employed in metal treatment is used for chromium plating over 50% is for decorative chromium plating (see Metal surface treatments). Hard chromium plating differs from decorative plating mostiy in terms of thickness. Hard chromium plate may be 10 to several 100 p.m thick, whereas the chromium layers in a decorative plate may be as thin as 0.25 p.m, which corresponds to about two grams Cr per square meter of surface. 

Hard plating is noted for its excellent hardness, wear resistance, and low coefficient of friction. Decorative plating retains its brilliance because air exposure immediately forms a thin, invisible protective oxide film. The chromium is not appHed directiy to the surface of the base metal but rather over a nickel (see Nickel and nickel alloys) plate, which in turn is laid over a copper (qv) plate. Because the chromium plate is not free of cracks, pores, and similar imperfections, the intermediate nickel layer must provide the basic protection. Indeed, optimum performance is obtained when a controlled but high density (40—80 microcrack intersections per linear millimeter) of microcracks is achieved in the chromium lea ding to reduced local galvanic current density at the imperfections and increased cathode polarization. A duplex nickel layer containing small amounts of sulfur is generally used. In addition to... 

Decorative plating primarily over bright nickel is estimated to consume about 2270 t worldwide. Some 60% of this is used in North America, and about 900 t in Europe. A relatively new method in decorative chromium plating is based on trivalent instead of hexavalent chromium, and this is estimated to total about 10% of the decorative market and is expected to increase. Chromic acid, which cost about 2.76/kg in early 1993, is the hexavalent... 

Other decoratively plated coatings produced in quantity are copper and copper alloys. Copper-plated hardware for cabinetry, lighting fixtures, household trim, and other uses is protected using a top coat of clear lacquer. Copper plating finishes are available with a variety of post-treatments to simulate antique or mstic appearances. 

Decorative plating, 9 765-767, 769 Decor paper, 18 129 Decorticated black pepper, 23 162-163 4-Decylaniline (4DA), 14 479-480 n-Decyl chloroformate, molecular formula, 6 291t... 

MAJOR PRODUCT APPLICATIONS adhesives, caulks, sealants, inks, paints, coatings, EMI control, gaskets, decoration, plating, composites, building products, computers, pastes for electronics, stucco, arts and crafts, smoke detectors, covers, printers, copiers... 

Final cleaning in a degreaser prepares parts for packing and shipping. Nonfer-rous metals, such as copper and aluminum, and decorative plated surfaces of chromium, zinc, and silver, are left clean, bright, and shiny. 

Electrodeposition has been used since the beginning of the century to form high-quality, mostly metallic, thin films car bumpers, decorative plating, metal contacts, and so on. It has recently been shown that high-quality copper interconnects for ultra-large scale integration (ULSI) chips... 

Acrylic resin formulations have been used for outdoor, weather-resistant adhesives. Pressure-sensitive acrylic adhesives are common on decals, bumper stickers, decorative plates, etc. Two-part thermosetting acrylic formulations have been developed and packaged for encapsulating, potting, and structural adhesives. Thermosetting acrylics cure by free radical-initiated addition polymerization. These materials can be cured at room temperature with benzoyl peroxide and an amine promoter (dimethyl aniline). 

See also painting plastics hot decorating plating printing on plastics. 

The Corrodkote test, ASTM B 380 [74], was developed by the American Electroplaters Society to improve the performance of decorative plating used on automobiles. The original test protocol used actual Detroit city road slush consisting of dirt, road salt, and water [72]. The Corrodkote test uses a slurry consisting of kaolin, cupric nitrate (Cu(NOj)2 SH O), ferric chloride (FeCl, 6Hj), and ammonium chloride (NH,C1) in deionized water [74], The slurry is applied to the samples being tested. They are then placed in the humidity chamber maintained at 38 + 2°C and a relative humidity between 80 and 90 %, with no condensation on the parts. Twenty hours is considered one cycle [20]. Upon completion of the test, the specimens shall be cleaned with a mild abrasive and fresh running water. Additional... 

Decorative plating of a very thin layer, 0.3 gm >, on nickel layers, e.g. on bicycle handlebars. The corrosion protection is created by a rather thick nickel layer, 10-20 p,m. 

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