Filtration lines are caused by air movement (where air is moving between the inside and outside and wherever there is a gap between the floor and walls). In many homes, the worst filtration soiling is on the stairs. Although, most carpet cleaners spend some time attempting to removing these filtration lines, along with the rest of the soils present, some cleaners do not spend any time on them, thinking: “They are not removable, so why bother?” The soils that cause filtration lines (in the cleaning trade, we refer to them as “soot lines”) are composed of burned petroleum (the by products of combustion). This is basically, soot. This is why most readily available cleaning products for the home have little or no effect on them.
Soot can come from cars, furnaces, wood fires, etc. In the cities, it is primarily from cars and furnaces, (including those furnaces in big buildings). In the country, it comes from cars and from wood fires. With the same types of carpeting, the problem is just as bad in the country as it is in the city.
Soot is composed mainly of solid particles, and adhere to carpet fibers by an electrostatic means. This is why most detergent cleaners alone will not have much effect on them. A cleaning agent that utilizes both a solvent and a detergent, such as Pre-Oil Break, will work better than a water-based product, without scrubbing with a brush.
Isopropyl (Rubbing) alcohol also works, but if you need to use a lot of it, remember, it is flammable, and could possibly cause a fire due to fumes traveling to an ignition source. While it does work, I don’t think it is a good idea to use. There is also an unpleasant odor from it that takes quite a while to dissipate, and could be objectionable to the customer.
Synthetic carpets are also petroleum based. “Like is attracted to like”.
Soot’s solid particles need suspension, and not being soluble, they do not dissolve. If you think of them in the same way you would a graphite spill under a recliner, and deal with them accordingly, you will have much better luck removing them.
My preferred method of removing these soot lines is to apply a neutral pH detergent, either by spraying on, or pouring on a small amount, then agitate with a special brush (although, most brushes will work to varying degrees).
I have (and use professionally) a special brush for this purpose (as well as a special narrow steam cleaning tool). It is only 1/2 inch wide by 2 inches long. This brush is the correct width for getting up next to the walls, especially on stairs. It has the correct degree of stiffness to scrub loose the solid particles clear down to the carpet backing, and the fairly “wet amount” of detergent keeps the solid particles in suspension, as well as dissolving any soluble soils until they can be rinsed or toweled up.
Sometimes, I will use my regular carpet wand, placing it parallel with the wall, and spray the areas needed, then extract. On other occasions, I use a narrow crevice tool for spraying and extracting. It all depends on how much soot is present and how long of a distance is soiled.
Question: Can I use an antistatic product to remove filtration lines?
Answer: I have never tried to remove soot with an antistatic product. It may work, but I think using anti-stat is going to create a problem. Carpets are in fact anionic. Most cleaning agents are anionic. A few of them are nonionic (All Bi-O-Kleen products are nonionic). All anti-stats are cationic. Whereas, cationics produce a positive electrical charge, anionics produce a negative electrical charge.
If you put an anti-stat on the carpet, being cationic, it will remove the negative charge from the carpet, as well as the anionic protector that is usually present. It will probably void the warranty (if any) on the protector and the carpet. Most all anti-microbials are cationic. All defoamers are cationic. Any time cationics are used, the protector must be reapplied, thereby reestablishing an anionic charge to the carpet.
It is a judgment call, whether to use cationics or not. Sometimes, you are forced to use them anyway, because of a specific problem.
The soot particles themselves are nonionic. The individual particles (while microscopic), are very large. I think of them the same way as I would a spill of graphite, like that under a recliner or office chair. More effective than just a steam cleaning by itself is using a soap and water type spot remover followed with brushing action and then, rinsing with HWE (hot water extraction).
Based on this thinking, the soap and water and agitation from the brush, loosens and suspends these particles better than the very thin solution of a steam cleaning, even with the greater heat and water pressure. A spot remover solution has about 1 ounce of detergent (soap) concentrate per quart of water. The steam solutions have an average of 8 to 16 ounces of detergent concentrate per 100 gallons of water. As I see it, extra detergent is needed to loosen the electrostatic grip of the soot particles, and hold them in suspension, for removal by a towel, steam rinse, or by bonneting or shampooing, etc.
To prevent these filtration soil lines from forming (or, after they have been removed), the carpet must be lifted off of the tack strip and all gaps must be caulked in order to keep the air from flowing through them. If you are going to do this work, you will also need to reinstall the carpet when the caulking is dry (after about 24 hours curing time).
This is a major task, therefor, most folks prefer to just deal with the filtration soil as it occurs. If you elect to have the sealing done professionally, it may cost several hundred dollars, but that is the best answer.
On my website, the brush I use is for sale and I also sell a product that is very effective for removing these soil filtration lines (Bi-O-Kleen’s Spray and Wipe Cleaner).
My website is here.
Gary Heacock -The Interstellar Crossroads of The Universe- http://www.heacocks.com