Nonstick, low friction coating but No PTFE

[rickraphael]

We are looking for an omniphobic, nonstick, low coefficient of friction coating for a kitchen device used for hand grinding relatively soft foods like herbs and spices. PTFE was our first choice but because this is being sold to the 'health conscious' market, it was eliminated as an option. (I know it's safe but "no PTFEs" is what they want!) We originally tested PTFE coatings against a variety of food products and the average static CoF was .30 which is what we are aiming for with a different coating

The device is used at room temperature, and the substrate is Al 7000 series. It must be FDA approved for food contact and cost is a consideration. There will be little or no abrasion in use. It should be not more than .002" thick. The parts are 2.5" diameter.

We would prefer to have the parts coated in China (where they are manufactured) by an American subsidiary if possible. Do any suggestions come to mind?

Thanks,

Rick

 

[IRstuff]

Are peppercorns "relatively soft?"

Have you considered the ceramic coatings currently used for non-stick? I would be concerned about durability of something like PTFE in a grinding application; I think there will eventually be sufficient wear to remove the PTFE. We once had a thread on the fact that cotton thread could cut through SS rollers. I would have thought that you would need a hard material for grinding applications.

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[rickraphael]

Thanks, not peppercorns, think dried basil, oregano, garlic, etc. soft stuff. We tested PTFE for a year with no wear at all.

 

[ornerynorsk]

I'd second Irstuff's recommendation of a ceramic coating. I do a lot of cooking, and I've recently been using ceramic over aluminum cookware. Incredible stuff. For practical purposes it does a much better job than PTFE for non-stick and cleanability, but it can chip if impacted by a hard implement or object.

It is better to have enough ideas for some of them to be wrong, than to be always right by having no ideas at all.

 

[rickraphael]

Thank you ornerynorsk and IRstuff. I'll look into ceramics. I cook a lot myself but I'm not familiar with ceramic coated cookware. Are these ceramics comparable to Teflon®? Any idea who's coating it?

 

[IRstuff]

They are supposed to be replacements for PTFE nonstick coatings and work quite well in certain application, but in others, they're worse than PTFE, w.r.t. discoloration and scorching resistance. I think most of the coatings are done in China, and seem to come in 3 flavors (colors) blue, green, and white. If you're in the US, Walmart, Target, Big Lots all sell one or more brands of ceramic coated cookware.

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[IFRs]

Would a hard anodizing work?

 

[rickraphael]

@IFRs
Hard anodizing is an interesting idea. We gave it a thought early on but rejected it because of color constraints and I didn't think it would have the lubricity. Have you had any experience with it?

 

[edrush]

You might look into something called DiamonDyze. I have no experience with it and hence can not endorse it. Not sure if the base coating is decorative or hard anodize. Probably not available in China.

This is where I read about it:

http://www.pfonline.com/articles/diamondyze-in-the-rough