Need a food safe encapsulant to coat a small electronic device.

[MarvintheMartian]

I need to coat or mold a small (2cm x 3cm x 0.5cm) electronics device (chips and coin cell battery) that will be placed into a drinking bottle. The liquids will be normal drinks (no alcohol). Does anyone have an idea for a particular product or a resource to find one?

Thanks,

DJ

 

[IRstuff]

Why not use the bottle material?

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[SwinnyGG]

Yep. Put it on the outside and cap it.

 

[btrueblood]

Whatever you end up using, make sure you secure it well to the container - that size is a perfect "choking hazard".

"Food safe" is a pretty generic term. It depends on how long the part you are introducing is in contact with the food, what materials can leach out of what you are introducing, whether it supports bacterial growth (either as a nutrient or a safe harbor for bugs), how cleanable/sterilizable it is. There are a plethora of regulations surrounding the subject, suggest you look at

http://www.nsf.org/

 

[MarvintheMartian]

I believe the mold process is too hot to use the same material as the bottle. The device has a small battery that is temperature sensitive. In general I'd like to avoid a cavity type approach to eliminate the chance for leakage.

The device has to go inside the bottle. There will be design considerations to prevent choking. I'll check out the NSF site.

My leading candidate is platinum cure PDMS. My concern is tearing from the inside. I may also consider coating certain spots to smooth them. Parylene is interesting as well however I believe is usually deposited as a very thin coating and it doesn't work well with other encapsulates.

The perfect material would be a low temp epoxy. I've been told a suitable epoxy doesn't exist.

 

[IRstuff]

People have figured out how to mold chocolate over ice cream, so you really should talk to manufacturers who may have already solved this problem, rather that assuming that there even is a problem and coming up with alternate solutions that aren't necessary.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[epoxybot]

You might consider Food Grade heat shrink polyolefin. Though it requires temperatures of 200-250F, the residence time is very short.

 

[djhurayt]

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