7 RINSES???!?!?!?!?!?!?!?!

[Designgeek]

Unimatic, yes, good point about water turbidity. In the case I mentioned above, the water is basically clean. Not quite clear, but certainly not the darker gray you see in the wash cycle. Clear enough to make out the details of the agitator at the bottom of 12" to 14" of standing post-rinse water in the tub.

I was thinking of getting a turbidimeter to do that specific test, but $800 is a bit out of my range for a specialized component for this project. Though I could make one from scratch using an LED and photocell assembly. Another version would be comparison with standardized halftone grays that could be printed on a laminated card and placed at the bottom of a given depth sample of water, or compared with water in a test tube.

 

[kenwashesmonday]

One reason the rinse water is not as dark as the wash water is that cold water does not make the dyes run like warm or hot water does. If you're doing a test for rinse water opacity, make sure the temperatures are consistant.

Ken D.

 

[Unimatic1140]

Good point Ken, and it probably would be best to use only white, dye free towels for a true test.

 

[lavamat_jon]

Different Types of Detergent

I have also noticed there are certain brands of detergent which will just not rinse out fully, no matter what brand you use. I tried Persil liquid once on my towels, and even on the 5th deep rinse there was visible suds and cloudy residue. The next day, when submerging a flannel (facecloth) that had been washed in Persil in the sink, the water in the sink instantly turned cloudy. However, with other detergents I use (such as Fairy or Ariel), I have noticed that the rinse water is just about clear by the 3rd of 5 rinses; and that the water in the sink doesn't turn cloudy if I submerge a flannel in it.

However I've heard from over at THS that a capful of vinegar in place of fabric softener both softens clothes and reduces detergent residue... never tried that myself so I can't comment on how effective that is.

Jon

 

[hoovermatic]

Residue

I have read somewhere that it is normal for a certain amount of suds to be evident in the final rinse water using modern detergents. I am neither agreeing or disagreeing with this as I haven't really given this subject that much of my energy. However, I think this statement was made by a detergent manufacturer so could be pretty worthless justification for using a third of a box of detergent to wash a few towels that really only need freshening up anyway.

 

[launderess]

Suds in Final Rinse

Don't know about powders, but beginning to think small amounts of foam left in the rinse when using liquid/gel detergents is normal. IIRC read on a surfactant supplier website or maybe it was a detergent maker's that seeing small amounts of foam in the rinse was normal, to a customer query.

Do know I could never get Wisk HE to "rinse" clean. Cheer HE is a bit better and believe it or not Cheer Free & Gentle liquid (long as one uses very small amounts). Mainly use Cheer Free liquid on sheets and other lightly soiled items I'm laundering in cool/cold or warm water.

 

[launderess]

Front Loaders and

Went to the locallaundrette last week to use their SQ 50lb washer and noticed something interesting. It seemed the washer was tumbling (one way)while water was coming into the unit and being drained away (flushing), for a period before each rinse.

At least this is how it seemed to me as the water level did not start to rise (indicating filling) for an interval awhile after water began to enter the wheel. Could see and hear water coming through the detergent dispenser, but peering down into the drum there was little water there. Again it just seemed as if the drain was open and the water was merely flushing down the drain.

If SQ home front loaders have this feature, it would make for interesting rinsing action.

Launderess

 

[lavamat_jon]

Launderess,

I believe that's their "spray rinse" action. Ipso front loaders in my local launderette fill for the last few seconds of the interim spin, and continues to "flush" for another 30 seconds or so before the water level begins to rise. So maybe this is either to give a "spray rinse" or to flush any suds from the spin down the drain. My AEG does a flush fill before each rinse to serve the exact same purpose.

This is an excerpt out of my AEG washer manual:

"If after the last rinse foam is still visible:

* Modern detergents can still cause foam in the final rinse cycle. However, the washing is still sufficiently rinsed."

So, maybe that links in with the point you brought up Launderess, that foam in the last rinse is supposedly normal.

Of course, as I've mentioned before, my last rinse water is always clear of cloudy residues/suds unless I am using Persil liquigel.

Jon

 

[Designgeek]

Good information, thanks.

This weekend, with a load of whites and two light-colored towels, I noticed that the final rinse water was entirely clear while filling the tub, so apparently there wasn't enough detergent left in the clothes to immediately start diffusing into the water. At the end of a 9-minute agitation it was slightly cloudy, such that I couldn't quite make out the bottom of the agitator, however there were no suds evident during agitation. Wash and rinse temps were lukewarm, about 100 - 105 degrees.

Re. excess detergent: I think what's going on here is the detergent manufacturers are trying to optimize for "most consistent dirt removal" rather than for "most efficient use of detergent," no cynicism or sarcasm implied. With an excess of detergent, every detergent molecule grabs hold of some dirt at one end and a water molecule at the other and, and gets rinsed out, taking all the dirt with them. However the excess detergent molecules don't have any more dirt to grab, so they grab something else: the cloth. Then in the rinses, some of this detergent gets loose again and turns into visible suds or graying of the water.

The outcome is, no dirt in the clothes, but a variable amount of detergent in them. Presumably detergent makers have tested to be sure the amount remaining isn't going to cause skin irritation for the vast majority of users, and of course the added perfumes give you the scent that "confirms" that your clothes are clean.

I don't know if there's any way to judge what detergent level *in advance* will result in all the detergent molecules are doing useful work grabbing dirt and few or none being left over to stick to the cloth. It's more a matter of skill and experience, i.e. being able to judge "how dirty this load is" and therefore estimate more closely "how much detergent to add," in which case, using the same brand of detergent and the same washer and cycles consistently over time probably helps.

 

[Designgeek]

This weekend I also noticed something else that I found interesting.

Pouring water into a spinning spin tub (1400 - 1600 rpm) does not really do the trick in terms of a good extract-rinse. Reason is, the water centrifuges out before it has a chance to soak through to the clothes at the bottom of the tub.

So the question for people who have Hoovermatics and suchlike, with the continuous rinse/spin function: How much water and how fast does it pour in there; and have you noticed whether the clothes at the bottom of the spin tub have gotten their fair share along the way?

Also, pouring water into clothes that have spun out but are still in the spin tub, is a big no-no: consistently produces a serious out-of-balance where the spinner bops against the wall of the spin tub (which, needless to say, I open the lid to shut off immediately this starts to occur).

However, what does work is to take the clothes out of the spinner and soak them in another container (with or without agitation), and then put them back in the spinner. That consumes minimal water and results in a decent extraction such that the final rinse water is much less cloudy than if this procedure wasn't done.

Design implications:

The vertcal-axis automatics that use a spin/extract cycle where water is sprayed at the agitator as the tub is spinning, are definitely on the right track here. Spraying water onto the agitator does the best possible job of getting it to splash out evenly across the clothes that are stuck via centrifugal force to the sides of the spinning tub, so the extraction is as evenly distributed as possible.

For comparatively smaller diameter high-speed centrifuges generally, whether in twin-tubs or in stand-alone units, a vertical tube at the center of the spin tub could be provided, with perforations, and with means of introducing water through the tube. A relatively narrow-gauge tube could be used, with perforations, and with a non-pressurized or neutral-pressure water inlet. Water would enter the tube at the rate at which it was sucked out by passing into and through the clothes as they spun.

Given the speeds and inertial masses involved, this is not an experiment I'm likely to try.

 

[westytoploader]

Interesting information! If I remember correctly, the Hoovermatics with the Auto-Rinse feature fill the stationary spin tub to a certain level, then spin the water out, repeating the process. Since I've never used one (this information is based on the March 1971 Which twin-tub report in the UK), I'm not sure if it can spray rinse during spin or not. Any UK member or twin-tub afficionado will be able to answer that. In the Which tests, none of the twin-tubs rinsed effectively in the spin tub.

When I had my Maytag TT, I would just fill the wash tub up and do an agitated rinse, then go ahead and spin the clothes out. Since it had no fill flume or auto-rinse feature, it was VERY time-consuming and ineffective to rinse in the spinner. Would have rather had a Hoover...

--Austin