Decreasing costs while reducing the complexity of designing hybrid fuel tanks

As the electrification race continues, there will be an increasing market share for hybrid vehicles—cars that partially run on fuel and electricity. According to IHS Markit, the path towards electrification is increasingly clear and the global shift towards electrification is moving at an accelerated rate—hybridization provides an important step for many manufacturers. Global powertrain production will experience more electrification throughout the next decade, which includes an increase in mild hybridization and full hybrid vehicles.  

There is a difference when it comes to fuel tanks used for hybrid vehicles and purely internal combustion engine (ICE) vehicles. Fuel tanks for hybrids are smaller than ICE tanks, yet they must withstand a higher over and under pressure. Plus, special injection-molded pillars, brackets and baffles are needed inside the tanks to withstand the pressure and suppress the sloshing of the fuel. To make these hybrid vehicle fuel tanks, HDPE/High-density Polyethylene and EVOH/Ethylene vinyl alcohol are frequently used, but there are downsides to the blow molding method that needs to be utilized. These downsides include:   

  • Less thickness control leads to increase of the overall weight of the tank.
  • The multilayer blow molding process requires more hardware investment and is therefore more expensive than monolayer blow molding or injection molding.
  • There is a higher risk of leakage from the joints.

As the hybrid vehicle market increases, reducing the complexity of the hybrid fuel tank is key to manufacturers. Using advanced polyamides can reduce the complexity of producing these tanks and create cost savings, thus, you can gain a competitive advantage through greater efficiency and potential cost-savings.

At Envalior, we offer Fuel Lock Technology—an effective and proven solution for superior hybrid fuel tanks. Offering excellent barrier properties in a monolayer material, Fuel Lock Technology offers weight reduction and less post-processing via an injection molding process. Compared to HDPE/EVOH material used for blowmolded tanks, it can combine good mechanical properties and barrier performance in one material. Processing the material by means of plastic injection molding offers the design freedom to apply local reinforcements, make optimal use of the available building space and integrate functional features. Additionally, no secondary operations are needed because features like baffles and pillars are designed into the tank and injection molded together with the fuel tank body.

Fuel Lock Technology is also sustainable

A monolayer hybrid fuel tank can be made of EcoPaXX® or Akulon® Fuel Lock.  EcoPaXX® is the material of choice if you want the fuel tank to be intrinsically salt spray resistant because the car platform has an open chassis design, and the tank is exposed to an outdoor environment. Also, we use 70% bio-sourced monomer, thus, EcoPaXX® Fuel Lock has a carbon neutral footprint.

EcoPaXX's unique combination of short chain C4, based on Envalior’s propriety technology, and long chain C10, derived from castor oil, gives rise to unique property combinations, linking the application field of long chain and short chain aliphatic polyamides. It balances the high crystallinity inherent to C4 polymers with the low moisture uptake and chemical stability more typical of long chain aliphatic polyamides. At the same time, EcoPaXX has an excellent surface finish, making it an ideal candidate for when performance, aesthetics and sustainability come together. Applying EcoPaXX® Fuel Lock grades have a big impact on what you can achieve in designing and manufacturing fuel tanks, yet a small impact on the environment.

At Envalior, we offer our customers application development support, including CAE design, permeation behavior prediction, thermal stability analysis and more.

View related data sheet

Learn more about designing bearing cages

Published on

16 December 2021


  • Fuel Systems (6)
  • Blog (354)
  • EcoPaXX in automotive (8)
  • Akulon Fuel Lock (12)

Materials solution for fuel tanks meets stringent emission norms and reduced space demands

Popular blogs


Bert Keestra

Application Development Engineer

Bert Keestra studied chemical engineering at the Technical University Eindhoven (TU/e) in the Netherlands. After he completed a PhD in polymer technology at the same university, he started working at Envalior in the corporate research department of materials science. In 2010 he transferred to the business unit Engineering Materials as product development specialist and later as application development engineer, focusing on composite pressure vessels.

Subscribe to our monthly newsletter

Leave your e-mail address below to start receiving the latest news about plastics, new products and events delivered to your inbox. 

I agree with Envalior's Terms and Conditions and acknowledge that Envalior will process my personal data for the purposes described in our Privacy Policy.