ETFE-Nylon 12 Multi-Layer Fuel Lines and the Requirements of a Changing Fuel Line Environment

Future fuel lines will have to meet far stricter requirements than current nylon 12 fuel lines are capable of meeting. New capability must be added in three areas:

1. 1)
   Permeation resistance
2. 2)
   Electro-static dissipation
3. 3)
   Chemical resistance

Fluoropolymers as a family have emerged as the highest performance polymers with respect to all three criteria. The drawbacks associated with fluoropolymers have traditionally been:

1. 1)
   High cost
2. 2)
   Relatively poor physical properties

The challenge for the fuel systems researcher was to develop a fuel line with the desirable properties of the fluoropolymers without the disadvantages. Further, emulating the desirable performance “fingerprint” of nylon 12 around which all current fuel line specifications are written would allow ready acceptance and enable safe and easy substitution. As there is currently no single material that approaches all of these requirements, a composite system is necessary.

A system that meets all aforementioned criteria has been developed using ETFE as the inner layer with nylon 12 bonded to it as the outer layer. Where electrostatic dissipation is required, two layers of ETFE are used with the innermost being conductive.