Help needed:Plastic or synthetic rubber selection

[BretMan]

Hello,

I need some guidance for the selection of the right material for springs. Basic criteria are that it must maintain its spring rating and its dimensions during variations in temperatures from about +20 degrees F to +110 degrees F. and not be expensive. Compression cycles won't be more than about 100 per day and about a second apart and it needs to hold its rating for at least 2 years.

I search for info. on neoprene and polybutadiene but don't really know if these are appropriate. Any guidance is much appreciated. Thanks.

Bret

Miami,FL USA

 

[CoryPad]

In general, polymeric materials make lousy springs. Are you certain you need a nonmetallic spring?

 

[patprimmer]

The best plastic spring is generally Acetal. It is used extensively as the springs under the keys in keyboards.

Having said that, even the best plastic spring is pretty crappy compared to a metal one.

Regards
Pat
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[BretMan]

Thanks guys. Yes, I see what you mean. I'm not finding plastics used for anything particularly precise but more for keeping a part in place. I can also see that over time they'll fail sooner than metal.

Here's a helpful post from isrealkk: "A stable spring material used for measuring devices where the elastic modulus stays constant over the range of temperature is Ni-span "C" or Iso Elastic. See "Spring Design and Application" Edited by Nicholas P. Chironis, McGraw Hill, 1961 "

Bret

Miami,FL USA