Laundry physics?

[supernova]

So, I'm doing a load of towels in my top loader washer right now. It's a large load.

Don't know why this hasn't occurred to me before now, but:

Does it take less water to rinse than to wash initially because the material is already wet?

[mcctatas]

1. Great...

now I wonder too!

[Xipe Totec]

2. No, not really

it takes more water to remove the soap, than it does to just slosh it around with your clothes.

[supernova]

4. Why is that?

Displacement? Exchanging soapy water in the towels for fresh water?

[Xipe Totec]

7. You don't exchange the water, you dilute the soap

Say you start with a gallon of water, wash your clothes in it, and drain the soapy water.

The clothes are still wet, so not all the water (or the soap) are removed. Let's say 1/10th of the water (and soap) remains.

You rinse with more water, bringing the volume back to a gallon. That dilutes the soap to 10% of the original concentration.

Repeat the process and you're down to 1% of the original concentration (1/1000 of the original soap remains).

No mater how many times you repeat this process, some of the soap will always remain.

Typically, you rinse twice, so roughly twice the volume of water to rinse than it takes to wash.

[Haole Girl]

3. Oh

I was hoping this would be a thread to explain lost socks.lol

[supernova]

5. Hee. Hee.

:D

I'm not a miracle worker!

:silly:

[Fire Walk With Me]

8. I believe Douglas Adams answered that vexxer

in his Hitchhiker's Guide series...

[Kali]

6. a little bit, yes

depends on how well your spin cycle works - one of the ways washers get their energy savings ratings is how well they spin out the water - if they do a crappy job, theoretically your drier has to run longer and hence use more energy. If you use solar for drying, that isn't so improtant.

[MissMillie]

9. probably

but not by much.

When a machine performs an initial fill (for washing) it probably takes more water to fill the machine because some of the water is absorbed by the clothes.

Whereas the for next fill (for rinsing), the clothes are already saturated.