deep sea

[motorworks]

Hi
I have a request to make a part out of "plastic"
I have a used sample, but no drawing or material list.
This part is going down deep in the North Atlantic (ie sea water)
The material looks like Delrin.
What would you think would be the best material for this application.
regards
eddie

http://www.geocities.com/motorworksnf/123

 

[patprimmer]

If you get samples of plastics known to be:-

1) Acetal (Delrin)
2) Nylon
3) HDPE
4) PET

Burn a small piece of each and smell a very small sample of the smoke.

Compare the smell to the sample you have.

If you expect a reasonable answer instead of a SWAG (Scientific Wild A** Guess), tell us what loads might be on the part and what other than (I guess) freezing cold sea water it will be exposed to.

I guess you intend to machine a one off part.

Regards

eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[Pud]

If you are making a one/two off, have a look at "Torlon":

http://www.solvayadvancedpolymers.com/products/bybrand/torlon/0,,329-2-0,00.htm

It ridiculously expensive but it will out-perform any thing else, and you will be on the "safe side" by a wide margin!


Cheers


Harry

 

[markruble]

Exactly how deep are you wanting to send this down? The key word you posted is "NORTH" Atlantic. Please remember that as you go deeper the water temperature gets colder and once you have gone beyond the depth that light can penetrate it gets very cold very fast. I am not sure plastic is the best selection of material for what you are wanting to do. Keep in mind there is a reason that submersibles are not made from what this material. At extreme depths the pressure upon the walls is unbelievable and what about extreme cold?

 

[dwightdixon]

You gave no indication what this part must do. If you think the part is Delrin, that is Dupont's trade name for acetel. Acetel is typically used for bearing and structual applications. It has a tensil strength of about 10,000 psi. Be careful with the "burn and sniff" test with acetel. It generates formaldahyde when burning. Very dangerous to smell. Chemical wiff testing is advised.