DuPont Performance Polymers responds to global PA12 shortage


These automotive fuel line quick connectors—injection-molded in DuPont™ Zytel® HTN54 Series PPA resins in replacement of nylon PA12—gain superior resistance to heat, and to ethanol, methanol and diesel biofuels.
Fiat is using Zytel® RS 1010 nylon in bio-diesel fuel lines, and was honored in 2011 by the Society of Plastics Engineers with its "most innovative use of plastics" award for replacing PA12. Zytel® RS 1010 and also modified 610 and 612 are effective candidates for these demanding applications.


The March 31, 2012 fire at Evonik's cyclododecatriene (CDT) plant in Marl, Germany, has led to a critical shortage of PA12 resin—a key component used in fuel and brake lines—and is threatening to disrupt global car production. The disaster has exacerbated an already tight supply situation for PA12, causing automakers to look for substitute materials.

DuPont responds


DuPont has been working on PA12 alternatives and is positioned to respond quickly. The company has established global development and supply teams to work with customers to quickly qualify alternative materials for use in brake and fuel components.


"The magnitude of the reported shortage will require close collaboration throughout the value chain to quickly qualify alternative materials that can be used to safely manufacture critical components, and to help ensure component supply is not interrupted," said Patrick Ferronato, Global Automotive Director for DuPont Performance Polymers.


Ready supply of alternatives


Several high-performance material families whose supply is not affected by the CDT crisis—DuPont™ Zytel® long chain polyamide product family comprising 612 and renewably sourced 610 and 1010, DuPont™ Hytrel® thermoplastic elastomers, DuPont™ Zytel® PPA and DuPont™ Vamac® ethylene acrylic elastomer (AEM)—are readily available as potential solutions for applications ranging from mono- and multi-layer fuel lines, fuel vapor tubes, PCV hoses, air brake hose and tubing, brake line coatings, servo brake tubes, vacuum brake tubes and fuel line connectors.


Most of these materials are already fully commercial in those applications, and many are based on renewably sourced ingredients, allowing automakers to adopt a more sustainable solution. DuPont has also committed to accelerating the introduction of modified Zytel® 610 and 612 products that were already well advanced in development when the PA12 shortage intensified. These additional long chain polyamide materials complement the product offering and are aimed at matching PA12 performance.


Accelerating market introductions


"DuPont has stepped up to this wide-ranging issue and is working with customers and OEM's to identify suitable alternatives from our already commercial portfolio of products. In addition, we are accelerating the market introduction and ramping up production of long chain polyamide grades from our development pipeline. This includes modified 612 and 610 products that are aimed at replacing PA12 on brake and fuel systems applications," said Alfonso Garces, Global Manager Specialty Products, DuPont Performance Polymers.


Replacing PA12


There are several commercial-grade DuPont polymers that can be considered as replacements for PA12, depending on the automotive parts required:


Mono-and multi-layer fuel lines

Zytel® nylon long chain polyamides offer varying degrees of flexibility balanced with resistance to zinc chloride, calcium chloride, hydrolysis and permeation, making them potential replacements for PA12. Many of the products are based on renewable content from castor oil derived from the non-edible castor plant.


PCV hoses

Hoses for positive crankcase ventilation (PCV) systems must resist aggressive blow-by vapors containing moisture, combustion by-products and unburned fuel. Depending on part design, flexibility and working conditions, DuPont can offer modified and heat stabilized Zytel® PA612 or Vamac® Ethylene Acrylic Elastomer (AEM) for PCV hose applications. Both resins are already commercial and can replace PA12 in this application.


Air brake hose and tubing

Zytel® nylon long chain polyamides offer superior chemical and stress cracking resistance for use in both mono- and multi-layer air brake hose and tubing applications. Hytrel® thermoplastic elastomer also offers a wide range of flexibility, mechanical strength and high temperature burst pressure resistance for these tube constructions.


Servo and vacuum brake tubes

Resins for servo brake vacuum tubes may differ in properties, depending on part design, working conditions, assembly process and OEM specification. Hytrel® thermoplastic elastomers offer the best combination of flexibility and thermal properties. Zytel® nylon long chain polyamides like Zytel® RS 1010 or modified 610 offer superior chemical and ozone resistance.


Fuel line connectors

Zytel® HTN54 PPA offers excellent chemical compatibility with, and resistance to, automotive fuels including ethanol and methanol bio-fuels, and bio-diesel. Available in conductive and non-conductive grades, Zytel® HTN PPA provides better heat resistance than PA12. While the mold-shrinkage factors of Zytel® HTN54 PPA are not exactly the same as PA12, they can often be processed through the same tooling with little or no refinement required.


Global resources


DuPont has committed global resources to work closely with customers to help identify material solutions and provide technical support. Although many possible PA12 alternatives are highlighted here, there are PA12 substitution challenges. For help understanding whether these materials can work in an application, or for more technical information, please contact DuPont.