"The tightness in the PA12 polymer supply actually started more than two years ago, caused by increased demand in photovoltaic solar and oil and gas applications, and customers began asking for replacements," said Lee.
"The largest and most critical area of replacement needed now is in fuel lines and truck air brake lines. In these, you're always trying to balance the flexibility of the material with chemical and salt resistance, and the material's processability. The properties needed can vary by processor, or application, or OEM. The trick is to balance the right potential substitute with those properties."
Other polyamide grades of PA 6/10 plastics such as Rhodia's castor bean oil-based Technyl eXten can replace nylon 12 in injection-molding parts like quick connectors for fuel lines. (Source: Rhodia)
The difficulty and the challenge are that PA 12 may have been used in applications where it didn't need to be, and where alternatives exist, said Lee. Every application needs to be reviewed on its own to see what's possible. The vast majority of PA 12 replacements will likely be based on other polyamide chemistries.
Other producers of castor-based polyamides include Radici Plastics and Rhodia. Rhodia is conducting trials of its Technyl eXten PA6.10 product for use in automotive and industrial tubing and flexible hoses, as well as fuel quick connectors, said Alan Dubin, business development and technical service manager, North America, for Rhodia Engineering Plastics, in an interview.
Technyl eXten 6/10 grades are available for both extrusion and injection molding, Dubin said. They are especially suited to fittings and adapters for engine fuel systems and flexible tubes for power-assisted control systems. In chemical resistance and mechanical properties for some components, such as quick connectors and other injection-molded parts, as well as in some extrusion-molded applications, these grades may actually perform better than PA 12.
"We've done three automotive customer studies for major manufacturers of fuel line quick connectors that show virtually no change in part dimensions or part performance," said Dubin. "They have evaluated our material in several different injection-molded products."
PA 6/10 has virtually the same range of operating temperatures as PA 12, with similar results in heat aging characteristics. Making the switch from PA 12 to 6/10 should also result in a substantial cost reduction. Dubin says evaluations of extrusion-molded product performance are ongoing.
This situation shows that there are real risks in the global supply chain. While this global supply may be effecient due to scale, there are many possibilities for disruption. I would have throght that the consumers of these materials would have plans in place before something like this happens.
naperlou, I was surprised to discover that the industry could go through such a shakeup when only one supplier went offline. Apparently, DuPont and others have already been working on replacements for awhile, as the supply has been tightening due to increased demand from other industries: solar and oil/gas.
Naperlou, the problem has cropped up repeatedly in the last 10 years. Two manufacturers in Japan represented a 25% loss of global silicon wafer production after the Earthquake.
The world is WAY too dependent on silicon wafers to tolerate that. The same applies to plastics.
JIT supply chains may be efficient, but only if the supply chain is guaranteed. It is not damage tolerant at all.
Engineers need to take a stronger stand proving this to the accounting department.
TJ, thanks for that comment. I was surprised to learn what a big market share Evonik had, and therefore what a big effect it could have when its plant went offline. I suspect the picture will look pretty different in the next few months.
Interesting to see how supply chains hold up to stress, no doubt about it. As they say, if you're going to put all of your eggs in one basket - then watch that basket! It begs the question as to whether the problem is a supply chain without any breadth of suppliers, or a supply chain in which the suppliers have too much risk. I haven't heard anything about the results of the investigation into the fire in the first place, which might be where the tru problem lies.
@Ann: Thanks for this informative article on a timely topic. I had heard that Evonik provided feedstock for as much as 80% of the nylon-12 supply, not 40%, as the article states. Of course, even 40% represents many tens of thousands of tons. It's no exaggeration to say that everyone is scrambling for an alternative.
I'm a little surprised you didn't mention Arkema's Rilsan nylon-11, which is based on castor oil and which you covered in an article a couple of months ago. According to that article, it is already being used in fuel line applications.
Schulman's Schulamid nylon-6,12 is another product worth mentioning. It's not renewably sourced, but could potentially be a drop-in replacement for nylon-12 in extruded hoses.
The fact that the industry was able to pull together through AIAG and come up with a common test strategy was a major accomplishment.
It will be interesting to see if any of the substitute materials catch on in the long run, or if everyone will go back to nylon-12 as soon as it becomes available again. There is certainly a potential for long-term use of renewably sourced plastics to increase as a result of this situtation. It all depends on how well they perform and how much they cost.
Dave, thanks for your input. The 40% figure comes from ICIS, the major industry market analyst, so I tend to believe them: http://www.icis.com/Articles/2012/04/30/9554265/news-focus-producers-scramble-to-provide-polyamide-12-alternatives-for-auto.html I agree that it will be very interesting to see if using replacements--and specifically bio-plastic replacements--will continue after the supply of nylon 12 comes back up. There are many other possible replacement products, including Arkema's, but the purpose of the article was not to give a detailed list of alternatives: that's been well covered already in the plastics vertical media and by ICIS.
Production of nylon 12 monomer feed stock is extremely difficult and expensive to complete on a large scale. The alternative plans of Dupont and others were most likely completed years ago as an attempt to take market share from Evonik, but they were not cost feasible. Now with end users scrambling to get some sort of alternative material, they are willing to pay a premium for the alternative material and the testing required to qualify it for use.
Tim, thanks for your input. As I reported, DuPont, among others, said that customers began asking for alternatives about two years ago when supply began tightening due to increased demand from solar panel makers and the oil & gas industry. Suppliers may well have begun those efforts even earlier internally. However, the main crunch here is caused by the material's use in automotive manufacturing, where changes in materials do not occur or easily. 5,000 hours, or about 7 months, is the usual required time for testing a new material for fuel lines, the main class of parts affected. This has somehow been fast-tracked down to 3 or 4 weeks by the AIAG's action.
@Ann: Any word on how EPA is handling this with regard to permeation requirements? In our application, there is a barrier layer which is made out of PVDF, not nylon-12, and this barrier layer is not changing. In our design, we rely mainly on this barrier layer (not the nylon-12 itself) to prevent permeation, so we don't expect any problems with EPA approval. But what about in cases where there is no barrier layer?
Dave, EPA requirements were not discussed regarding replacement materials. That said, can you tell us more about the context for the barrier layer you mention? Are you referring to the multi-layer tubing mentioned in the article?
@Ann: Yes, I'm refering to multilayer tubing used for fuel lines. The EPA has regulations regarding evaporative emissions for both automotive and non-automotive applications. Hydrocarbons can permeate through plastic tubing and escape into the atmosphere. It's important to limit this. (This is what our barrier layer does).
I'm not sure what the automotive requirement is, but the marine requirement is 15 grams per square meter per day maximum. This is measured according to one of two SAE standards, depending on whether it is plastic or rubber hose. However, since I'm not directly involved in regulatory compliance, I'm not sure exactly how this needs to be documented to EPA, or what the approval process is.
Thanks, Dave. Like I said, I've seen no mention of EPA requirements. Those could be part of the 5,000 hours of testing, or it might be something already done separately by the materials producers to meet their own automotive standards, since I doubt EPA approval could be achieved in the 3-4 week compressed schedules.
Andrew Morris designed a circuit that could detect a stroke victim's groan and convert the sound into a signal so caregivers would know when help was needed.
New disc magnet motors fit into the design trend of stepping up to closed loop performance while maintaining the cost advantage of stepper motor technology.
At the Design News webinar on June 27, learn all about aluminum extrusion: designing the right shape so it costs the least, is simplest to manufacture, and best fits the application's structural requirements.
On April 21, NASA launched a novel project, putting into orbit three satellites that employ an off-the-shelf commercial smartphone as the control system.
From Dell / Intel® New Paradigms in Design Work Scott Hamilton, vertical market strategist for Dell Precision workstations, 5/2/2013 5
Early in my career, I worked as a draftsman and remember the days of drawing on vellum with numbered pencils and Mylar with plastic lead. This was a fun experience in the sense that I ...
I've been using workstations for more than 10 years and love finding ways to get more performance from my system. With demanding professional applications that require more power each ...
A lasting memory from my first job as an engineer in an auto assembly plant is standing on hard concrete at six in the morning, vending-machine coffee clutched in hand, listening to ...
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.
To save this item to your list of favorite Design News content so you can find it later in your Profile page, click the "Save It" button next to the item.
If you found this interesting or useful, please use the links to the services below to share it with other readers. You will need a free account with each service to share an item via that service.
Tweet This
0 
