Due to the hygroscopic nature of sodium-containing solutions, the most effective application of FluoroEtch is by immersion. This permits the reaction to take place in a closed or nearly closed container. A thirty to sixty second exposure to warm etchant (50°C to 60°C) is recommended. Agitation of the parts during immersion enhances the etching effect. This is sufficient to affect a color change to dark brown (in the case of PTFE and PFA; FEP and ETFE show a very slight color change) indicating a more carbonaceous layer at the surface and rendering the fluoropolymer completely water-wettable and bondable. Following the etching process, the parts should be washed in an isopropyl or methyl alcohol bath, washed in hot water with a detergent, rinsed well and dried thoroughly.
Acton Technologies, Inc., 100 Thompson Street, P.O. Box 726, Pittston, PA 18640. Tel: 570-654-0612; Fax: 570-654-2810.