Powder Coated Tough - Fall/Winter 2007 - (Page 25) investment it took to get into pretreatment. He started with a small dip tank rather than the multi-stage systems he had been reading about, and it took up very little floor space. He did not need conveyors or automatic operation. Also, the need for electricity was almost non-existent because there is only a pump and filter, plus very limited exhaust. A severalstage water-based system Bridgeport Powder Works treats thousands of parts, such as those seen here, would have been far out of using a one-step organic phosphating process. the company’s budgetary range, Boehm says. After installing the one-step process, Boehm reports that he no longer has to rework any parts. In addition, the powder bonds so tightly to the surface that its removal was extremely difficult even with a stripper. Boehm adds that the coating didn’t chip off when parts were once accidentally dropped on a The Process T his one-step organic phosphating process* is based not on water but on environmentally friendly solvents, which have extremely low emission of volatile organic compounds (VOCs). Because it is based on a different philosophy and chemistry than conventional water-based systems, the process itself is completely different as well. The system cleans, phosphates and seals in a single stage, by either dip or spray. No water is used and it is not rinsed. The buying and treating or disposing of water is eliminated, and water permitting and water pollution issues are avoided entirely. The process does not create sludge, so it only requires filtering out the fines that come in on the parts, and does away with the environmental issue of sludge dumping. Oils that come in on the parts are not treated as waste, so there is no oil dumping. Instead, the oils are captured in the sealant and used as a plasticizer to lend flexibility to the seal and protect against chipping and cracking of the topcoat. The seal provides weeks to months of protection against flash rust. Parts can be coated or painted at leisure, avoiding the downtime during breaks or at the end of the day. The seal also creates flexibility in permitting storage of treated parts until orders are processed for particular topcoat colors, for example. The system is completely unheated so it avoids all the costs of natural gas, which are very significant now and rising. It is very stable, because the bath elements are used up in proportion, and the bath therefore never needs to be dumped. More of the same fluids are added as the bath is used. And it is very simple to operate, saving labor costs and producing stable finished part performance as well. Using the one-step organic process, a part is treated for one minute to clean, phosphate and seal. Then it is dripped/blown off and dried, and it is ready to be painted or stored for top coating at a later date. What does “environmentally friendly” mean as applied to this process? As noted, the VOCs emitted are very minimal because of the very high flashpoints and boiling points of the products and because of their extremely low vapor pressures. Moreover, the fluids contain no carcinogens, mutagens, halogenated compounds or ozone-depleting compounds. They are easy to use from a fire safety point of view, having flashpoints in the 168° to >212° F. range. *The process is offered by Carpenter Chemicals LC, Alexandria, Va., under the trade name Plaforization™. www.powdercoating.org 25 http://www.powdercoating.org
For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.