Automotive Fuel Systems Challenge Thermoplastic Materials

The automotive fuel systems business represents a $14 billion global market that provides opportunities for a wide range of thermoplastic materials from high density polyethylene to more exotic materials such as ethylene and vinylidene-type fluoropolymers and long chain polyamides. Recently a number of diverse factors have challenged the use of these materials. These factors have included:

  • The Great East Japan Earthquake that strained the supply of a variety of fluoropolymers materials
  • The fire at Evonik’s cyclododecatriene (CDT) plant in Marl, Germany on March 31, 2012, that severely strained the supply of polyamide 12 (CDT is a raw material used for the production of polyamide 12)
  • Moves to partially electrified vehicles that are challenging fuel tank engineers to develop pressure-resistant plastic tank designs
  • Changes in government regulations such as in California that will require fuel systems to have reduced emissions while also incorporating ethanol in emission test fuels

Polyamide 12’s unique properties position it as the most common material used for fuel and fuel vapor lines, quick connectors, valves and other miscellaneous fuel system components. These properties include its resistance to various fuels and road salt and superior mechanical properties for extruded fuel lines. Its poor permeation resistance requires polyamide 12 to be used in multilayer constructions. Automotive OEMs collaborated anxiously with their suppliers to find suitable replacements to polyamide 12 material when possible. This replacement is particularly difficult for multilayer constructions where the complete construction can be impacted by a material change to a single layer. In the longer term the polyamide 12 crisis has motivated a significant further development of potential replacement materials including a variety of long chain polyamides such as polyamide 6,10, 10,10 and 10,12.

The development of plug-in hybrids and turbocharged gasoline engines results in fuel vapor purge problems for evaporative emission control charcoal canisters. This has resulted in the development of pressurized fuel tanks that reduces the need for purging the canister. Maximum design pressures for such tanks are typically limited to 350 mBar but the large flat surface area of many automobile fuel tanks poses challenges for plastic materials. The plastic fuel tank industry has spearheaded a number of innovations that will facilitate the use of plastic tanks for partially electrified vehicles.

California’s Advanced Clean Cars Program will require vehicle evaporative emission test fuels to include 10 percent ethanol. This poses a significant challenge to plastic materials used in fuel systems since fuel permeation through plastics materials peaks at ethanol concentrations between 10 and 15 percent in gasoline. As a result, the automotive OEMs, already under significant cost pressures due to the increasingly competitive nature of today’s automotive market, will have to further upgrade the material selection for fuel systems.

For further information on this 438 page report, please contact Dr. Joel Kopinsky, Managing Director, at email(at)itbgroup(dot)com or call (1) 248-380-6310 with any questions.

About The ITB Group
The ITB Group, Ltd. is an international automotive technical/business consulting firm headquartered in Novi, Michigan, USA. It provides technical and business advice to OEMs, component and material suppliers in North America, Europe, and Asia. The company is a leading expert in the use of polymer materials for automotive applications including under-the-hood, interior and exterior applications. The firm further provides guidance for various forms of supplier transactions.

Further background can be found at