Precipitation On The Rise

[mrcleanjeans]

I would love a thorough answer to this question which I've asked before.Thanks and here goes.When powders replaced phosphates with washing soda,manufacturers warned,GE was especially vocal on this ,that the soda would not fully dissolve in cooler temps and would react with hard water forming limestone(calcium carbonate) residues in the clothes and washer and whites would get greyish,colors dulled, and cleaning much lower.They said to soften the water mechanically or with a non-precipitating softener or use a liquid in that case.But they made a big,big deal about non-phoshate powders to such a degree that I use liquid.What are your thoughts on this and why are powders generally favored around here in light of all this?

 

[frigilux]

Generally---and with new liquid formulations, the gap is closing---I find powders clean a little better. Having said that, liquid Tide with Bleach Alternative scored second only to powdered SA8 in Consumer Reports' recent test. I used liquids for years---especially Tide HE---but now I find I like the old-schoolness of powders. There's something pleasing about measuring and pouring powder and making sure it dissolves before adding clothes that appeals to me.

There is probably some chemistry-oriented answer to why powders have overcome whatever doomsday scenarios were predicted for them, but I'll leave those explanations to people who don't believe that chemistry and electricity and architecture are magic, LOL.

 

[supersuds]

I was worried about the lack of phosphates, too, as a die-hard powder user, but have to say they have not caused any calcium buildup, and its really been years now. I guess the problems have been largely solved.

 

[mrcleanjeans]

Thanks,but how? That sodium carbonate is still used.Of course,the better detergents use silicoaluminates also,yet soda is still present.

 

[launderess]

Only the cheapest powders rely mostly on sodium carbonate as a builder/water softener. TOL brands such as Tide use a complex chemistry of washing soda, zeolites, phosphonates, and other substances to equal the performance of phosphates. Mind you it takes several chemicals to perform all the functions phosphates do all by themselves.

There is a world of difference in washing say with Tide verus Arm & Hammer powder for most.

 

[sudsmaster]

I resolve the issue by mixing phosphates (STPP) in with a regular powder (usually Sears HE). I find that the phosphates effectively prevent the carbonates from precipiting out on the fabrics or washer parts.

Interestingly, the other day I fetched a gallon container of Sears HE liquid from the garage, to refill a half-gallon size container. It had been sitting in the garage for a few years. After refilling the smaller container, I noticed that there was a precipitate - like rocks - rattling around the bottom of the larger container. My guess is that this must be the sodium citrate that is added to most liquids as a water softener/break. It must have come out of solution after prolonged standing through the winter months. Sodium citrate is a bit better behaved than sodium carbonate, it's best described as a semi-precipitating water softener. But I bet if you have really hard water it could precipitate out in the wash.

 

[mrcleanjeans]

Yes but would the carbonates fully dissolve,even if you have the precipitation licked?

 

[sudsmaster]

would the carbonates fully dissolve?

Why wouldn't they? Sodium carbonate is highly soluble in water.

If you mean calcium or magnesium carbonate, well, the idea is that STPP is so powerful that it grabs the calcium and magnesium (and other awful ions like iron) more tightly than sodium carbonate, and thus prevents precipitation of mineral carbonates. The reason for this is probably due to the fact that STPP and other polyphosphates form complexes around hard water mineral ions, holding them in suspension, whereas only a single sodium carbonate binds with a single mineral ion. In effect the polyphosphates crowd out the carbonates. At least that's my slightly educated guess, and it seems to be borne out by the empirical evidence.

 

[launderess]

Everybody Brings Something To The Party

Many packaged water softeners, such as Amway and the old Calgon powder used a blend of phosphates and soduim sequesticarbonate (sp?), and one thinks about it the same thing happens when one adds STPP along with powdered laundry detergent, as most contain 15% to 40% washing soda.

L.