[Dave_Lee]

Put some pre mixed cleaning solution on a white plate let it dry and see how much residue you get

With respect Ian, that's not the same. Whilst rinsing with a detergent you are removing the majority of the solution as a whole from the carpet, not just the water. In your example only the water is being removed by evaporation leaving all the detergent on the plate, that's why there is so much.
You will find that if you do the same with an acid rinse solution you will get the same result.
I think this is why some have a mind block over detergent rinsing. Their reasoning seems to be that a plain water rinse removes the prespray whereas a detergent rinse leaves some detergent in the fibres. In fact both leaves an amount of detergent in the carpet, but the best extraction detergents are thus designed to do so.
Dave.

[Doug Holloway]

Hi Guys

There are so many factors which can effect this.

If you are applying a high pH, highly buffered pre spray, then a little squirt of pH 4 rinse is going to make virually no diffrence.

Volume is another very important factor, if you are rinsing with a TM then virtually no detergent will be left.

Cheers

Doug

[Neil Williams]

Whilst rinsing with a detergent you are removing the majority of the solution as a whole from the carpet, not just the water. In your example only the water is being removed by evaporation leaving all the detergent on the plate, that's why there is so much.

How can that be?
If 5% of the volume of solution put into the carpet is a detergent then from the moment you stop extraction there will still be 5% of that solution in the carpet.
From that point the water element evaporates off leaving the detergent part still there, which will reform as a solid.
Anyone who has done window cleaning with purified water will understand what I am saying, because that's why you have white spots left on glass if you use tap water.....the white spots being the deposits that were held in suspension as tap water. Purified water having nothing in it can't leave deposits behind, hence the clean spotless windows.

[Dave_Lee]

Whilst rinsing with a detergent you are removing the majority of the solution as a whole from the carpet, not just the water. In your example only the water is being removed by evaporation leaving all the detergent on the plate, that's why there is so much.

How can that be?
If 5% of the volume of solution put into the carpet is a detergent then from the moment you stop extraction there will still be 5% of that solution in the carpet.
From that point the water element evaporates off leaving the detergent part still there, which will reform as a solid.
Anyone who has done window cleaning with purified water will understand what I am saying, because that's why you have white spots left on glass if you use tap water.....the white spots being the deposits that were held in suspension as tap water. Purified water having nothing in it can't leave deposits behind, hence the clean spotless windows.

Sorry Neil, I don't agree.
By your example of the 100% solution, 95% is water and 5% is detergent.
For arguements sake lets say just 90% of the solution is removed during extraction.
That is 90 % of the water plus 90% of the detergent as it is all extracted as a whole, you are not only extracting water but the detergent part too.
90% of 5% detergent is 4.5% leaving 0.5% or almost zero in the carpet.
In actual fact with a powerful TM more than 90% is extracted.
Dave.

[Neil Williams]

Sorry Neil, I don't agree.
By your example of the 100% solution, 95% is water and 5% is detergent.
For arguements sake lets say just 90% of the solution is removed during extraction.
That is 90 % of the water plus 90% of the detergent as it is all extracted as a whole, you are not only extracting water but the detergent part too.
90% of 5% detergent is 4.5% leaving 0.5% or almost zero in the carpet.
In actual fact with a powerful TM more than 90% is extracted.
Dave.

Dave.
A litre of detergent solution will contain water, detergent and all the other stuff that the water boards put into the it. You can keep sucking it all you want but there will always be the same percentage of chemicals in that water when you stop....you can't suck the chemicals out and just leave pure water behind. Hence my example about window cleaners and the water they use.
If you are using detergents to rinse with then at the same time as you are extracting you are replacing with new detergent mix....you can't alter that.

[Neil Williams]

As an afterthought we are talking about the same thing aren't we ie those who mix up a detergent mix that goes in the tank, not those who use just water (or acid rinse) in the tank?

[Mike Halliday]

using Dave's figures.......

 if using a detergent means you will leave 0.5% of cleaning detergent in the carpet then you will actually leave the carpet cleaner than a fresh water rinse, as I believe a detergent rinse removes more dirt than the fresh water rinse so...... all a detergent needs to do is remove 0.5% more dirt to leave the carpet with less foreign matter than the fresh water rinse

[Dave_Lee]

As an afterthought we are talking about the same thing aren't we ie those who mix up a detergent mix that goes in the tank, not those who use just water (or acid rinse) in the tank?

Neil, we seem to be on totally diferent wavelengths here.
We are talking about a detergent mix in the tank or in the chem bottle as with TMs.
What the water people put in the water is irrelevent as it both methods use water.
When you stop extracting, the solution flow to the carpet also stops. Actually it stops before as you finish with further passes without any solution flow.
You are correct that as extraction takes place further solution is added, but this too is being extracted all the time at the same percentages as the on the very first pass with the wand.
Dave.

[Billy Russell]

i do understand what neil is saying! the percentage of the moisture left in the carpet is still the same percentage in the tank!! That right Neil? 

[Neil Williams]

i do understand what neil is saying! the percentage of the moisture left in the carpet is still the same percentage in the tank!! That right Neil?  

Of course it is.
Let's try it this way. Put a red colourant in the solution tank mix, extract all you want and unless you have the worlds best extractor which takes everything out leaving the carpet dry then there will be a red colourant mix still in the carpet. The water will evapoate away but the colourant will remain but some seem to believe puttin more of this mix in somehow magically gets it all back out again and more. Alternatively extract with just water and eventually you will remove all the colourant and just leave water behind)
We can keep this going all night if you want because I know I'm right and science proves you can't simply extract the bits out of water that you don't want to be left behind. (unless we start talking reverse osmosis - anyone got one of those fitted to their CC machine - thought not)

[Dave_Lee]

Neil,
I see what you are saying now. Yes the same 5% of the solution left in the carpet will be detergent.
However what I am saying is, that it is only 5% of the 10% of solution left in the carpet after extraction has finished, or 0.5% of the original amount of detergent added to the water in the tank.
If the dilution rate is say, one scoop per gallon of water in the tank, then if for example, it takes 6 gallon say to clean an average lounge, that's 6 scoops of detergent.
After extraction only 10% solution remains in the lounge carpet, of which 0.6% of a scoop is detergent (10% of 6 scoops).
As this is spread throughout the lounge carpet, just over half a scoop of dry detergent left behind, is so small an amount it is neither here nor there.
Some people go on as though there is abundance of detergent left in the carpet or upholstery and this is just not the case. 
If there was a lot of detergent left in the carpet through using a detergent rinse, then we would have problems, but there isn't.
I'm not arguing with you, I think we just misunderstood each other.
Dave.

[Neil Williams]

If the dilution rate is say, one scoop per gallon of water in the tank, then if for example, it takes 6 gallon say to clean an average lounge, that's 6 scoops of detergent.
After extraction only 10% solution remains in the lounge carpet, of which 0.6% of a scoop is detergent (10% of 6 scoops).
As this is spread throughout the lounge carpet, just over half a scoop of dry detergent left behind, is so small an amount it is neither here nor there.

And on that point we are friends again as we are both correct
I'm not disputing that you can get away with leaving a certain low % of detergent in a carpet which will have little after effect. It all depends on your goal, my personal objective is always to get all dirt-contaminants-solutions out but with some jobs like the pub I've got coming up will not get the results with just a prespray and water rinse, and afterall it's going to get slaughtered over the next few weeks so what's the point in leaving it perfectly neutral.

[peter maybury]

One point that I have not seen anybody make is that with a truckmount the majority of us use a much lower dilutuion rate in our solution containers. For instrance on my machine I would put 30 scoops of hydra dri into the tank and that could clean 1000- 1500 square mtrs. I always prespray and aggitate and more than often rinse with hydradri but the dilution rates are only a fraction of what I was using with portables. This would be a very imporant facvtor if using crista green or double clean........

Peter
www.carpetcleanercardiff.com

[Carpet Dawg]

Like Mike and a few others, I use detergent in the tank 90% of the time on upholstery and carpets.

I go through 11 tubs of formula90 or 110kg a year!

The results are clear to see. If you want maximum soil extraction (and especially on mingers) you need a detergent in the tank.

Big companys like Prochem and Chemspec wouldn't invest $$$$ a year in R&D or sell a product that had a negative effect on carpets.

As already said, only a little detergent gets lift in the carpet and what is left is self neutralizing anyways.