W. DOUGLAS OBAL, DuPont Company, Wilmington, DE, USA

ABSTRACT

Ductwork systems are used in the semiconductor and allied industries to safely transport highly corrosive chemicals and vapours. Over time, however, these substances can invade the walls of the duct by the process of permeation, resulting in leakage or even loss of structural integrity. The mechanism of permeation is explained in detail, yet predicting its effects can still be risky. Metal ducts having a thin fluoropolymer lining have demonstrated that the effects of permeation can be controlled and the risks mitigated.

 Permeation: Its Effects on Teflon® ETFE Coatings on Stainless Steel Corrosive Fume Exhaust Duct