STPP vs TKPP

[srswirl]

On another forum Charlie's Soap responded to a poster's problem of dingy whites. In that message, they advocate using TKPP (potassium diphosphate aka tetra-potassium pyrophosphate) instead of STPP (sodium tri-polyphosphate) because it rinses out cleaner. I've been using STPP for a couple of years and have had excellent results...including clean rinsing. So...I am surprised to hear this. They also imply that TKPP is more "boisterous" (read better?) than STPP.

Was just wondering if those of you who are more chemically literate than most of us have any comments/advise on this.

Thanks!

 

[sudsman]

We tried tkpp here

and stpp is better for our use. Did not see that it did any better at all and was a lot harder to come by . Cannot speak for present however as that was about 6 or 8 years ago. unless over used I have NEVER had a problem with STPP rinining at all. Usually a couple of split rinise @ 2 min each and thats it.

 

[sudsmaster]

TKPP *might* be more stable in aqueous solution that STPP. After some googling, I found that Armor-All spray cleaner uses TKPP, as well.

I don't know if there is any difference in rinsability between TKPP or STPP.

 

[srswirl]

Thanks!

Thanks guys. I think I'll stick with my trusty STPP.