FUEL TANK GASKET AND METHOD FOR ITS MANUFACTURE

摘要

A fuel tank gasket (20) which before use consists essentially of a) 30-90 % by weight porous base material and b) 10-70 % by weight additive having the requirements that it is compatible with said porous material is taught. The porous base material of the gasket (20) is preferably expanded polytetrafluoroethylene and the additive is selected from the group consisting of perfluoropolyethers, polysiloxane, butadiene-acrylonitrile co-polymers, polyesters, polyethers as well as functionalised and fluorinated derivatives thereof. Preferably the additive is perfluoropolyether or a functionalised derivative thereof. A method for manufacture of the said fuel tank gasket comprising the following steps is furthermore described: a) a first step of manufacturing a porous base material (90), b) a second step of preparing an additive (70) in fluid phase, c) a third step of applying said additive (70) to said porous base material (90), d) a fourth step of drying the base fuel tank gasket (90). The fuel tank gasket (20) is used in transportation vehicles, such as an aircraft, for ensuring that fuel (7) does not leak out of the fuel tank (5) and water does not enter the fuel tank (5) and contaminate the fuel (7) therein.