When using soap in a top loading washer or wringer machine
You want a lively rich layer of thick suds as shown:
You notice a recurring theme in Ivory Snow advertising; the supposed absence of "harsh detergent deposits"....
Well Ivory Snow would leave things washed "softer" wouldn't it?
Unlike powdered detergents then and largely now pure soap Ivory and others did not contain washing soda or other alkaline substances. Thus no such residue and or harsh feeling due to textile fibers being roughed up by high pH substances.
The "deposits" spoken of are what happens when you use precipitating water softeners (washing soda, caustic soda etc...) which can cling to fabrics if laundry is not rinsed well.
The other issue is something one has spoken about before; encrustation. Basically when using high or moderately high pH substances for laundry it causes textile mesh fibers to open. This is a good thing because soils can thus be easily flushed away. Problem is that if those fibers close down before all soils and residue are rinsed away that residue becomes trapped. Result is harsh, scratchy feeling laundry that soon becomes dull and tattle tale grey.
The old way was to have one, two or more boiling, hot or at least warm rinses to make sure fabrics were free of residue before a final cold (or warm) rinse. This and or a "sour" would be used after the third or so rinse to dissolve any remaining alkaline substances out of the wash.
Liquid laundry detergents are either neutral to only slightly base. They clean more based upon surfactant and enzyme action rather than brute high pH strength. Thus risk of encrustation is reduced. More importantly for commercial laundries and linen services things last longer and they can skip the sour and perhaps few rinses. This allows them to save money on supplies, energy, time and water.
For wash loads that need extra oomph, commercial laundries have access to products like emulsifiers and breaks that can be used with liquid (or powder) detergents as needed.
Finally as for all those soap products and their "harsh deposit" advert claims. Light duty detergents such as Dreft and Woolite soon displaced soap for "nice things". Eventually even Ivory Snow succumbed. P&G discontinued it as a soap and reformulated it as a light duty detergent.
On another thing; to combat that "harsh" feeling early detergents left with laundry a new product hit the market, fabric softener. First used by commercial laundries and later introduced to consumers early formulas were nothing more than an emulsion of fats, oils and or tallow. The last should sound familiar since that is what soap is often made. So now P&G and others found away to sell "soap" back to American housewives who gave up using that for wash day. They now just added the stuff to the rinse.
Dryer sheets both early and many today are nothing more than fabric coated with stearic acid, or fatty alcohols and or fatty acids. Again, soap more or less.
[this post was last edited: 2/24/2017-05:18]
