sudsmaster
Well-known member
OK, here's the skinny:
The best soil suspension agent, bar none, is STPP. It also has other admirable qualities, but I'll stick to just this one for the sake of this discussion.
In phosphate free detergents, the soil suspension chore goes to CMC, or carboxy methyl cellulose. This is a wood pulp product (processed) that looks much like lint when dry. When moistened, it has a viscous quality in concentration. CMC is used both in American laundry detergents and in Persil.
Persil may contain other substances to replace the other functions of STPP, such as zeolites. Zeolites are effective for softening water without causing a precipitate, but they have no soil suspending activity.
Seeing that Persil uses pretty much the same soil suspending agent as American phosphate-free laundry detergents, I tend to doubt that American detergents are less able to withstand long hot wash cycles than European detergents. It may be, however, that the lack of zeolites and over-reliance on sodium carbonate for water softening in American detergents results a greater tendency for hard water precipates being redeposited on clothing. But I doubt this has any relationship with heat or wash time.
Here's a link that discusses CMC and other cellulose compounds, and here's a except:
6. Carboxymethyl Cellulose
Carboxymethyl cellulose, generally as its sodium salt, is the most widely used cellulose
ether. CMC is water soluble with a DS of 0.4 to 1.2 in common applications. It was
originally used as a replacement for natural gums in adhesives, but it has since developed
many uses of its own. Sodium carboxymethyl cellulose is readily water soluble because of
its ionic nature; its largest use is in laundry detergents, where it helps to suspend soil
particles during washing. This resistance to greases and soil has made CMC useful in
fabric sizing as a soil repellant. Because CMC is completely nontoxic, it is used in many
food applications, where its affinity for water prevents drying of the product. Although it
is generally no longer used as an adhesive, per se, it is still used in adhesives as a
thickener.
http://www.fpl.fs.fed.us/documnts/pdf1994/bauma94a.pdf
The best soil suspension agent, bar none, is STPP. It also has other admirable qualities, but I'll stick to just this one for the sake of this discussion.
In phosphate free detergents, the soil suspension chore goes to CMC, or carboxy methyl cellulose. This is a wood pulp product (processed) that looks much like lint when dry. When moistened, it has a viscous quality in concentration. CMC is used both in American laundry detergents and in Persil.
Persil may contain other substances to replace the other functions of STPP, such as zeolites. Zeolites are effective for softening water without causing a precipitate, but they have no soil suspending activity.
Seeing that Persil uses pretty much the same soil suspending agent as American phosphate-free laundry detergents, I tend to doubt that American detergents are less able to withstand long hot wash cycles than European detergents. It may be, however, that the lack of zeolites and over-reliance on sodium carbonate for water softening in American detergents results a greater tendency for hard water precipates being redeposited on clothing. But I doubt this has any relationship with heat or wash time.
Here's a link that discusses CMC and other cellulose compounds, and here's a except:
6. Carboxymethyl Cellulose
Carboxymethyl cellulose, generally as its sodium salt, is the most widely used cellulose
ether. CMC is water soluble with a DS of 0.4 to 1.2 in common applications. It was
originally used as a replacement for natural gums in adhesives, but it has since developed
many uses of its own. Sodium carboxymethyl cellulose is readily water soluble because of
its ionic nature; its largest use is in laundry detergents, where it helps to suspend soil
particles during washing. This resistance to greases and soil has made CMC useful in
fabric sizing as a soil repellant. Because CMC is completely nontoxic, it is used in many
food applications, where its affinity for water prevents drying of the product. Although it
is generally no longer used as an adhesive, per se, it is still used in adhesives as a
thickener.
http://www.fpl.fs.fed.us/documnts/pdf1994/bauma94a.pdf
