The Expanding World of PTFE

No development in the history of fluorocarbon polymers has been more remarkable than that of the microcellular expansion of PTFE without the use of blowing agents. This article summarises the development of the GORE-TEX TM process by W.L. Gore & Associates, Inc. PTFE (polytetrafluoroethylene) has been referred to as both the ‘ultimate’ and the ‘eccentric’ thermoplastic. Its extraordinary properties are now well known to polymer technologists. I.C.I, plc has manufactured it under the name of Fluon * for more than 30 years, as have DuPont under their brand name Teflon ** . It possesses outstanding chemical inertness, excellent electrical and thermal insulation properties, a wide operating temperature range and exceptional non-stick and low friction characteristics. Apart from its important role in engineering and electrical applications as a solid, full density polymer, the most dramatic impact on its commercial development came with the discovery of the GORE-TEX matrix expansion process. This process, developed by W.L. Gore & Associates, is not dependent on the use of ‘blowing agents’. The microcellular structure is achieved by mechanical stretching under specific conditions; in this way there is no adulteration of the PTFE purity.