DuPont™ Delrin® and Zytel® go global in a new automotive fuel filter manufactured and designed by Parker Hannifin


New fuel filtration module by Parker's Racor Filter Division Europe comprises DuPont™ Delrin® acetal resin for the filter assembly and DuPont™ Zytel® high performance polyamide for the filter bowl and head to achieve an optimum combination of mechanical strength, stability, heat and chemical resistance, and anti-static properties.
Digby Scott, Research and Development Engineer at Parker Hannifin's Racor Filter Division Europe (left) discusses the merits of DuPont™ Delrin® acetal resin and Zytel® high performance polyamide in the company's new fuel filter module, with Robert Coates, Automotive Market Development Consultant, DuPont Performance Polymers.


Automotive fuel filters do a tough job. Not only must they supply the fuel system with ultra-clean, particle-free and water-free fuel, but also function reliably for the lifetime of the vehicle in a harsh environment involving aggressive fuels, wide operating temperatures, high pressures and significant vibration loads. On top of that, they must meet today's demands for higher efficiency at lower weight.

Increasingly, automotive OEMs are turning to advanced plastics such as DuPont™ Delrin® acetal resin and Zytel® high performance polyamide to save weight and reduce cost in critical components, while maintaining or improving performance. Zytel® is already a common replacement for aluminum in fuel filter components.


Parker Hannifin chooses Delrin® and Zytel®


In a state of the art example, Parker Hannifin's Racor Filter Division Europe has selected Delrin® and Zytel® for a new fuel filtration module specified by a market-leading OEM to equip light commercial vehicles for global markets.


Delrin® is used for the filter assembly, while the filter bowl and head are molded from glass-reinforced Zytel®. To meet static dissipation requirements, the filter head and part of the filter assembly use anti-static grades of the two DuPont polymers to avoid ignition of the fuel by static electricity.


The customer comments


AutoFocus asked Digby Scott, research and development engineer at Parker Hannifin's Racor Filter Division Europe, to comment on the fuel filtration project, and the advantages of working with DuPont:


AutoFocus: What is the function and operating environment of the fuel filter?


Digby Scott: Its function is to provide the vehicle fuel system with clean water-free fuel, protecting the high-pressure fuel system components to ensure longevity. The fuel filter must operate and maintain mechanical integrity within harsh environments, with a variety of fuel types including standard EN590 diesel and B100 biodiesel, temperatures from -40°C to 140°C, internal pressures to 5 bar, and up to 6g vibration loads.


AutoFocus: Why did you select Zytel® and Delrin® for Parker Racor's new fuel filtration module?


Digby Scott: Zytel® was selected for the filter housing because of its mechanical strength and material stability at temperature. The conductive grade of Zytel® was specified for its anti-static properties.


Delrin® was selected for the filter element because of its chemical resistance properties, ease of molding and compatibility with an infrared manufacturing process. Again the conductive Delrin® was chosen for its anti-static properties.


AutoFocus: Can you comment on the benefits of working with DuPont in addition to the products themselves?


Digby Scott: Support from DuPont in terms of CAE Moldflow modeling has been a powerful tool to ensure critical design features of the product are molded as intended. Additionally, DuPont has worked directly with our injection molders to ensure that tool design for the material and material process conditions are captured.


AutoFocus: Is the filter already commercial, and is it specified for the European market only or for other markets as well?


Digby Scott: The filter is currently in production for a market-leading OEM in the European light commercial vehicle market. This business extends into 2013 for European vehicles and onwards to North America and Rest of the World markets.


AutoFocus: What sort of testing did the components undergo?


Digby Scott: The fuel filter has undergone and successfully completed an extensive product verification test cycle that simulates accelerated aging of the lifetime of the components. Examples of validation tests carried out by Parker are:


• Hot soak endurance: 2000 hours at 90°C, plus 100 hours at 110°C in fuel EN590 and B30 biodiesel
• Thermal cycle: -40°C to 100°C, 200 cycles of 2-hour cycle time
• Pressure pulsation: 1 Hz 3x105 cycles at 0 to 1.5 bar
• Static burst: at 21°C and -29°C and 5 bar
• Elevated temperature testing: 215 hours at 140°C with 90°C fuel
• Vibration: 300 hours, 1.5 mm peak-to-peak displacement, based on vehicle road load data cycle
• Zinc Chloride soak test: 120 hours at 40°C
• Chemical resistance testing.


Also, the OEM has carried out extensive in-vehicle trials, including winter low temperature and summer hot performance testing, plus durability and environmental chamber tests.


AutoFocus: Based on this experience, do you plan further fuel filter designs using Zytel® and Delrin®?


Digby Scott: Zytel® and Delrin® have proven to be suitable and successful materials for fuel filter components and will be used in other OEM specific fuel filter designs.


About Delrin® and Zytel®


DuPont™ Delrin® acetal resin bridges the gap between metals and ordinary plastics with a unique combination of creep, fatigue and abrasion resistance, coupled with strength, stiffness, hardness, dimensional stability, toughness, solvent and fuel resistance, low wear and low friction. To find out about the many advantages of Delrin®, visit:


DuPont™ Zytel® is the industry's broadest portfolio of nylon resins produced by the largest, most globally networked nylon manufacturer exclusively focused on the resins market. It includes: Zytel® PLUS, maintaining performance levels much longer than traditional nylons despite long-term exposure to hot oil, hot air, calcium chloride and other aggressive automobile chemicals; Zytel® HTN PPA grades designed for extremes, retaining stiffness, strength and mechanical properties despite exposure to high temperatures, long life coolant, chemicals and moisture; high-performance renewably sourced Zytel® RS containing between 63% and 100% renewable content. For more information, visit:


About Parker Racor


The Racor Filter Division Europe is part of the Parker Hannifin Corporation, a global leader in motion and control technologies and systems for the commercial, mobile, industrial and aerospace markets, with annual sales exceeding $12 billion in 2011.


Fuel filtration systems developed by Parker's Racor Filter Division Europe have been an integral part of many of these systems. The Racor name has been at the forefront of fuel, air, oil, and coolant filtration systems for internal combustion engines and fuel delivery since 1969. Its reputation as an innovative, technology-driven company is the result of a commitment to manufacturing excellence, working closely with customers and suppliers to develop filter media, materials, and system configurations that meet customers' evolving requirements. For more information visit:


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