Metal Finishing Guide Book

2012 Organic Finishing Guidebook Issue

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Page 24 of 331

is introduced as the final rinse and all vapors are exhausted after each cycle and passed into a solvent recovery system. With the sealed chamber control of solvent loss exceeds 90%; in other words virtually no solvent escapes. Programmed automated operation permits a variety of cleaning programs including cold or warm solvent dipping, as well as vapor degreasing. Solvent re- covery cycles make use of advanced methods of carbon adsorption and hot air des- orption. The manufacturer of one such unit, a "closed open-top degreaser" with a large cleaning chamber, claims that solvent emission losses average less than 100 lb/yr. Solvent concentrations in the work area of the "closed open-top" unit av- erage between 5 and 10 ppm, well below the permissible exposure limits set by OSHA for the chlorinated solvents. Although these "emissionless" units can be costly, a number of plants in the U.S. have found them economical because they provide excellent compliance with safety and environmental regulations,conserve solvent, save floor space, and provide excellent parts cleaning performance. Several brands of these "emis- sionless" degreasers are available in North America today. Most producers and distributors of chlorinated solvents provide support for solvent users. The Responsible Care initiative of the Chemical Manufacturers As- sociation, to which all solvent producers subscribe, and the Responsible Distri- bution code of the National Association of Chemical Distributors require mem- bers to share product stewardship information, safety training, and regulatory data with customers. When selecting a supplier be sure to review what kind of sup- port is provided. 23

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