High Temp/Chemical Compatibility Polymer 2

[nlj]

I'm looking for a material that can be used as an alternator guard. Therefore this material would be close to an engine and would see high temperatures. Additionally, the material has to be compatible with brake fluid, engine oil, diesel fuel, transmission fluid and coolant.

I was originally thinking a PPS, but was curious to see what you all would recommend. I think Buna-N would give me my chemical compatibility, but wouldn't withstand the temperatures. Ideally I'm looking for something with some rigidity, but that is the least of my concerns.

Thank you for the assistance.

 

[CoryPad]

PPS would work, but likely is more than is needed for this application, and more expensive than other options. A lower cost alternative would be glass & mineral reinforced polyamide, such as DuPont Minlon or DSM Akulon or Stanyl:

http://www2.dupont.com/Automotive/en_US/products_services/engineeringPlastics/minlonPA.html

http://www.dsm.com/en_US/html/dep/akulon.htm

http://www.dsm.com/le/en_US/stanyl/html/home_stanyl.htm

 

[Compositepro]

BMI resin (bismaleimde) with fiberglass is often used in aerospace engine applications like this. They can be used at over 600F. If you are only making a few composites can be much cheaper than tooling up for thermoplastics.

 

[patprimmer]

GF Nylons 6 and 6.6 are used extensively under bonnet for applications like radiaror header tanks inlet manifolds, fuel filter canisters and many electrical parts and housings and timing chain tensioners and engine covers.

If extensive exposure to brake fluids is a requirement, polyesters are normally chosen.

What is the maximum temperature it will ever see and what life does it require at the highest temperatures regularly seen.

Stanyl nylon 4.6 has better temperature resistance that 6.6 and is sometimes used in timing chain tensioners and was used on at least one turbo diesel inlet manifold, however it is somewhat more expensive than 6 or 66 and a little more difficult to mould due to higher temperatures and even more sudden transition than 6.6. I have even seen Stanyl tested successfully as a valve spring retainer although as far as I know, it never went commercial.

Unless it gets very hot due o being close to the exhaust, heat stabilised 25% GF type 6 nylon should do.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers for professional engineers

 

[CompoMan]

Have you consider glass fibre reinforced phenolics