Polishing UHMW?

[mingmongmang]

Hi,

Can anyone recommend a polish/technique to get a very smooth surface on a UHMW? Ideally something easily obtainable and not requiring a particular skill.

The part is a mold and I'm hoping a smoother surface will improve release of shore A 40 silicone parts. Currently the surface has machining and sanding marks in it and it's not releasing even with various mold release agents.

Thanks!
Jon C.

 

[patprimmer]

Flame polishing.

Regards
Pat
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[mingmongmang]

I've read that it's very easy to 'oxidize the surface' by going 5 deg C over the temp needed to melt the surface. Do you know if this is correct and if an oxidized surface can be restored?
Thanks.

 

[Demon3]

Firstly, PE resists oxidation well. It will not oxidize from heating just above the melting point. There is also antioxidant in there to prevent that.

Intentional oxidation of the PE surface is well known as it improves adhesion. Flame or plasma treatment for example. The surface "heals" itself over 1-2 weeks as the oxidized groups move within the bulk and away from the surface. This is well documented for example in some very thorough papers by Sutherland.

Chris DeArmitt - PhD FRSC CChem
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