Air Filtration Lines

Ugly Air Filtration Lines

Filtration Soiling

One of the most dreaded soiling conditions known to carpet cleaning professionals is "Soil Filtration Lines." Understanding their causes, where they appear, and how to prevent and remove them is highly important to professional carpet cleaners and their customers.

What are they?

Soil filtration lines, sometimes known as "pollution stains" or "air filtration lines," are caused by smog, dust, carbon monoxide, and other airborne pollutants that pass through the carpet pile. As the contaminants pass through the carpet, the fibers act as a filter to remove the fine particles of airborne soil. The condition manifests as charcoal gray or black lines affecting the entire carpet fiber and the backing material. The increased level of air pollution in large cities and industrial areas makes filtration soiling a common occurrence. The problem is intensified by the increased popularity of light beige and off-white carpets. The condition is much more likely to be present where fireplaces, wood-burning stoves, and particularly kerosene heaters are used extensively. The burning of candles and heavy smokers in the home or building can also contribute significantly.

Where are they located?

They are distributed throughout the building via the heating & air conditioning system or through natural convection currents in the building structure. Black or gray marks appear around the edge of a room, the edges of stairs, underneath doors, and around central heating & air conditioning vents. In virtually every home or building, gaps are found at the lower edge of walls, between steps and the walls of a staircase, between base­boards and the floor, and between the sub-floor and the drywall. Pollutants are forced from the crawl space and unseen, open areas, through the unsealed gaps, through the backing of the carpet, past the face fibers where the pollutants are filtered, and into the room. Sealing the cracks with caulk can eliminate the problem or force it to occur in another area. Filtration lines can take weeks, months, or even years to appear.

Olefin and polyester fibers show the greatest affinity to filtration soiling due to the oily nature of the pollutant and the oil-loving characteristics displayed by these fibers. This chemical attraction can cause a reaction whereby the oily deposits become a part of the carpet fiber, making them nearly impossible to remove. However, the olefin and polyester dyes' stability allows for greater aggressiveness when attempting removal.

Nylon carpets are easier to clean because they do not have as strong a chemical affinity to filtration soils. However, these stains can be tough to remove, even on nylon.

How can they be removed and prevented by the homeowner?

The longer the problem goes untreated, the more difficult it is to correct. A homeowner with severe filtration lines should vacuum the edges of the carpet with a crevice tool weekly. In the early stages, using a high-quality, non-sticky, encapsulating spot remover such as our POOF is very effective. In advanced conditions, some improvement is the most a homeowner can expect.

Can they be removed in the advanced stages?

In advanced stages, Filtration Lines cannot be corrected by the homeowner. It takes a true professional with the proper knowledge and professional products to correct the condition.

NOTE: The removal of advanced stages of Filtration Lines DOES NOT fall under regular carpet cleaning; instead, it falls under the restoration category and will take considerably more time and money. Professional carpet cleaners should charge accordingly.

What product is needed to remove them?

Spot-N-Boost is a fantastic product for removing these ugly stains. See the Tech-Bulletin for Spot-N-Boost. Oxi-Moxie is great for preventing them from coming back quickly; but they are likely to come back in time unless the underlying structural problems of the building are remedied. Again, be sure to charge accordingly if you provide this service.

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