Thermoplastic polyurethane (TPU) for drinking water?

[Felipe28]

I would like to know if any Thermoplastic polyurethane (TPU) is suitable for drinking water. I believe there should be many kinds of TPU, in which case it would be interesting to know if all of them don´t have problems if in contact with potable water.

Another thing would like to know if there is a time frame for the time TPU could be in contact with the water without releasing any toxic materials.

 

[patprimmer]

They are often used in jumper valves in water supply taps, so I guess those grades must be approved.

Any major reputable manufacturer should be able to supply documentation supporting which grades are approved.

Regards
Pat
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[Pud]

It's not so much a case of can polymer 'X' be used with potable water - it will depend on whether a particular type or grade has been submitted for relevant approval, which costs!!

e.g. one PU grade might be approved - another manufacturer's identical equivalent might not be.

As Pat suggested, you need to ask PU suppliers if they have had any approvals given for their materials for your market.

H

http://www.tynevalleyplastics.co.uk

Why be happy when you can be normal?

 

[dwightdixon]

Many TPU's contain bpa, which some people have made a big noise about. The requirements of conveying potable water are different than the requirements for bottle storage. The exact usage should be reviewed with the material supplier.

 

[Felipe28]

Thank you for your answers. As I can see from them, not all the PUs are certifies for working with drinking water (my application is in pump systems).

I have my production in China so I asked some people there to find out if their chinese suppliers of PU have certification, but maybe I should assume they don´t. Maybe these certifications (NSF 61 or BS 6920) are only met through big companies who make these polymers and not small suppliers.

Regards

 

[Pud]

Here are a few sorts of PU approved for the UK. Note some are coatings in the list.

http://www.wras.co.uk/Directory/materials_list.asp?Section=5297

Rgds

H

http://www.tynevalleyplastics.co.uk

Why be happy when you can be normal?

 

[patprimmer]

If in China, you need to ensure your moulder really does use the specified material. This may require some diligence and lack of trust on your part, even if you supply the material. They may just mix it up with other grades by accident or careless conduct or they might sell it off for a higher price then use a cheaper replacement. It has been known to happen both ways.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules