Fluoropolymer Lining, 300F 2

[NPKresults]

Hello,

For an upcoming process mixer we are looking to line the vessel with a fluoropoymer. The problem is that due to heat of reaction, the operating temperature will be about 300F. Most people have declined to quote, stating that although the material can take the heat, there is problems with adhesion above about 230F. I finally found a company willing to quote, although I have not been able to speak with their chemist yet, I have been told that this coating will be good to 400F. Although I was not given all the details of the material, I have been told it is impregnated with silica to achieve the high temperature capability. I think the starting compound is E-CTFE but I am unsure. Does anyone have any thoughts on such a material? I am mainly concerned with the adhesion factor. Thanks for your assistance.


Danny B

 

[Demon3]

There are high temperature fluoro coatings available for oven trays and such surfaces. I looked at them in the past. One of the coatings was from a company called CCC and the other was called Duralit. You're right that pretreatments to maintain adhesion is the hard, but not impossible part.


There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[NPKresults]

Thanks Demon3. The company I am thinking of using is called Sermatech. Do you have any thoughts on insulation? The lining will be going on a carbon steel shell, are there any guidlines you could give me concerning the steel temperature vs. adhesion? Are there any surface treatments I should be thinking about?

 

[Demon3]

The companies we dealt with also supplied the surface treatment advice and primers. I guess you'll have to keep checking for companies to help you and see who is able to supply you with the whole package.

I did testing on the durability and adhesion of the coatings but we were at the mercy of the coatings companies to supply the coatings so I can't advise on what was in their materials.


There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell

 

[kenvlach]

NPKresults
Have you taken care of this issue?

I don't understand why you were given such low temperature limits; PTFE (polytetrafluoroethylene) and PFA (perfluoroalkoxy) nonstick coating formulations can have continuous use temperature of 260°C (500°F). The usual difficulty in applying is reaching high enough temperature to fuse cure the coating.

Whitford (Manufacturer of the largest, most complete line
of fluoropolymer coatings in the world):

http://www.whitfordww.com

DuPont™ Teflon® Product Selection Guides:

http://www2.dupont.com/Teflon_Industrial/en_US/products/selection_guides/index.html

Usually, a copolymer is applied as a binder/base coat, then the pure fluoropolymer is the topcoat.

 

[NPKresults]

Kenvlach, Thank you for your information. I have contacted whitford regarding the issue. At the moment I have decided to go with a specialty FRP shell as I have information that it has been used with success and it is much more economical. As for the mixer blades I plan to coat them with either a flruoropolymer from whitford or sermatech, or to coat them with a ceramic based epoxy from MetalTek. Plant start-up is scheduled for summer '08 and I will post the results once they come in.