by Jeff Cross, executive editor
When trying to determine why some stains are tougher than others — stains that are of the same content — think about simple chemistry.
Anything that stains has some type of chemical component. Red Kool-Aid has a red dye. Tar is petroleum-based. Coffee is an acid-based beverage with tannins. Red wine has natural colors and tannin from the skin of the grape.
At the same time, each fiber has a chemical component and a liking for certain things.
We all know that nylon “likes” acid dyes. It’s the type of dye used by carpet mills for nylon, unless they use a solution-dyeing process. In that case, a pigment is used.
That means that nylon, if acid-dyed, is going to have a natural affinity for acid-dye stains. This is the reason carpet mills add “stain blockers” to nylon carpet.
Olefin likes oily soils. That means a bit of tar on an olefin carpet is going to be much more difficult to remove than a bit of tar on a nylon carpet. At the same time, olefin fibers typically reject acid dyes, tannins, natural juices, etc.
Polyester is a “cousin” to olefin. It also likes oily soils, but isn’t “friendly” to normal liquid spills, including acid dye stains, natural juices, tannins, etc.
One definition of all of this can be: “Stains are made of chemicals with loose ends. These loose ends stick to loose ends on which they stain.”
That may sound simplistic, but it’s a good description of what occurs when something is spilled, dropped or tracked onto a carpeted surface.
There has to be an “opening” in the fiber that the stain likes. A good example is polyester and mustard. Polyester is dyed using a disperse dye system, and mustard, that villainous enemy of all carpet cleaners, contains a disperse dye. While polyester withstands most food and beverage spills, mustard will often bond with it, creating a tough stain.
That doesn’t mean you can’t remove a mustard stain, but out of most stains that can end up on a polyester carpet, this will be one of the toughest.
Real-life scenario — nylon carpet
Let’s say a cup of coffee is spilled on a beige nylon carpet. The result is a big, dark brown, really ugly spot.
You go to work, and after typical spotting efforts on your part, you find that about 95 percent of the coffee is removed, but the remaining spot is now a stain. Unacceptable. You dig into your stain kit and use your favorite oxidizing solution. After about 15 minutes of work, applying the chemical and heat, then rinsing repeatedly, the stain is gone.
This is a success story, but with a twist. You didn’t expect to spend an additional 15 minutes on that spot. You had to go to more trouble than you thought before you started working. It only took 5 percent of that 8-ounce cup of coffee to create trouble and more work for you. It was that 5 percent that had what it takes to cause a stain on that nylon fiber. It was that 5 percent that had the loose ends (the natural tannin, most likely) that the nylon fiber liked and bonded with.
But the same spill on an olefin carpet would no doubt have rinsed easily and created no extra work on your part.
Become a ‘stain detective’
For stain removal, think about the surface that holds the stain and what it “likes” and “doesn’t like.” Stains and fibers are to the law of attraction.
If an olefin carpet has a small acid dye stain, success is normally achieved with simple cleaning. And with olefin, you can use a wider variety of cleaning chemicals.
But if it is nylon with a small acid dye stain, typical cleaning may not suffice. You may need to work harder on that stain, but with a proper fiber and stain education, you can be prepared to spend the time necessary.
Keep in mind that various fiber blends in carpet can affect cleaning efficiency.
Jeff Cross is the executive editor of Cleanfax and is an industry trainer and consultant. He can be reached at [email protected]