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Bushing for 100C, 212F, replace PEEK with cheaper polymer?

Bushing for 100C, 212F, replace PEEK with cheaper polymer?

Bushing for 100C, 212F, replace PEEK with cheaper polymer?

(OP)
Hello.

I am thinking of if there is a cheaper polymer than PEEK for a bushing.
The max surface pressure is 20Mpa 2.9psi.
The motion can be described as slightly pivoting.
And the shape of the bushing is:
Inner diameter = 15mm , 0.6 inch
Thickness = 1.5mm , 0.06 inch
 /|  |\
 ||  ||
 \|  |/

They are going to be injection moulded.
We will do around 300 000 pieces but the most will done in POM for lower temperature applications.

Thanks

RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?

Have you tried nylons 66 and 4.6

Regards

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RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?

(OP)
Thanks for the answer.
I forgot to say that they must be food grade.
I don't think they are food grade?

RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?

I am sure they can be. They can even be medical implant grade.

Regards

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RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?

(OP)
Thanks again, can the nylon 66 be used in this temprature in water? The application is a steamer.

RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?

Ummm what temperature.

What expected life.

Pure water, typical water supply water or something else.

Nylon 66 will degrade in water at 100 deg C

I would need to look up some tables to determine the rate.

Unfortunately the best heat and hydrolysis stabilisers loose the food contact status.

Life would be a lot easier if you stated most of the requirements up front instead of bringing them out one at a time.

Regards

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RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?

There are special grades of Nylon that absorb less water but still need to watch clearances or the bush will grab the shaft/axle.  Also use a resin with Aramid or Carbon fiber to aid stability.  Carbon will cause premature wear of the other surface though, where the Aramid (Kevlar) will not.  

We use this in down-hole (oil/gas) drilling situations where there is oil, water, gas etc at temperatures up to 140 C without problems but the fiber is important.

Cheers Geoff

PS I'm assuming that the 2.9 psi is the correct pressure?

RE: Bushing for 100C, 212F, replace PEEK with cheaper polymer?


Some cheaper alternatives to consider:

PPA (LNP and others)
PPS (Glass and PTFE filled) - e.g. Ticona Fortron
Partially aromatic nylons such as Grivory made by EMS Chemie.

PPA has a narrow processing window but any half-decent moulder should be able to run it.

PPS needs 135 Deg C tool temp so unless tool is insulated and/or elecrtically heated choose last...

Grivory has potable water approvals in the EU - you will have to check with manufacturers for the others.

Cheers


Harry

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