The makeup of the toughest stains

by Jeff Cross

It’s a fact: Some stains are tougher than others.Think about that last job you completed yesterday.

That bit of tar that you tried to remove? You are still upset that it left a small, yellow stain on the carpet.No matter what you did yesterday, that yellow discoloration wouldn’t budge.

It doesn’t look too bad, and you hope the customer’s eyesight isn’t too sharp.But the job you did last Monday – another bit of tar on the carpet, same scenario – well, that tar cleaned up completely and left no yellow stain.

Why is that?Or what about that job from last Tuesday.You remember: A third grader spilled some cough syrup in two different rooms in the home.In one room, you removed the cough syrup stain in two minutes, but in the other room it took you 15 minutes.

Why is that?What makes a stain a 'miserable' problem?When trying to figure out 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 tough tannin. 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 what the carpet mills use to dye nylon carpet, unless they use the solution dyeing process.That means that nylon is going to have a natural affinity for acid dyes: Kool-Aid being an acid dye that will easily stain nylon (this is why carpet mills add "stain blockers" to nylon carpets, to hinder this).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, it typically rejects 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 really happens 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 to prove this is polyester and mustard.

Polyester is dyed using a disperse dye system, and mustard - that villainous enemy of all carpet cleaners worldwide - contains a disperse dye.

So while polyester withstands most food and beverage spills, mustard will 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 carpetLet's say a cup of coffee is spilled on a beige, nylon carpet.

The result is a big, dark brown, really ugly spot.You are asked to clean that spot.So you go to work, probably after your customer used six different chemicals from under the kitchen sink, and would have used six more but ran out of stuff and didn't have time to get to the local Wal-Mart.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, right? You know the customer has good eyesight.So you dig into your stain kit, using your handy, trusty oxidizer. You add a bit to the stain, add some safe heat, and after about 15 minutes of your valuable time and a few choice words muttered under your breath, 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 one spot. You had to go to more trouble than you thought before you started working.It only took five percent of that eight ounce cup of coffee to create trouble and more work for you.It was that five percent that had what it takes to cause a stain on that nylon fiber. It was that five percent that had the loose ends (the natural tannin, most likely) that the nylon fiber liked and accepted as a guest in its home.But the exact same spill on an olefin carpet would have rinsed away so easily that you start thinking that everything should be coated in a layer of polypropylene.You wonder if the stuff is sold at the hardware store and what your spouse would think if you brought some home.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 strict adherence to the law of attraction.If an olefin carpet has a small acid dye stain, success is normally achieved with simple cleaning. Not always, but normally.

And with olefin, you can be more radical with your cleaning chemistry.But if it is nylon with a small acid dye stain, typical cleaning may not suffice.You may need to alter the color using specialized stain removers because the nylon "likes" the stain so much it's going to fight your efforts.