Many cleaners struggle with removing soil filtration lines - it's time consuming and requires specialized tools and solutions to be effective.
What causes soil filtration lines?
Carpeting acts as a filter, separating particulates and pollutants from the air as it moves throughout the structure. These soils consist of very fine micron-size particles that are most often oily.
Here's some of the science behind soil filtration lines: As air moves through a structure, warm air is attracted to colder air and colder surfaces, especially the gaps and voids commonly found in floor and wall structures. The temperatures in these areas tend to be lower than the ambient room temperature. When air moves to and through these gaps, it leaves fine particulate and oily soil behind. Filtration soils are commonly found are stairs where there is a void or unheated space below, under doors that are normally closed, and often around the perimeter of rooms.
In some cases, you’ll see little black dots on carpet along the walls that are darker than the rest of the filtration soiling. This is caused by the carpet being installed onto the tack strip. The pins on the tack strip have punctured the backing structure of the carpet and have created small holes and are allowing air and heat transfer with less resistance, in essence filtering more air than the rest of the surrounding fibers.
Another underlying principle is polarity. Unlike most other soils found in carpet, oils are non-polar molecules – they have a very strong attraction to other non-polar molecules, but they have no polar attraction to water (oil loves oil but hates water). Most synthetic fibers are derived from or contain some petrochemical (oil-based) components and therefore are extremely lippo-phillic (oil loving) and this is the greatest reason filtration soil is hard to remove.
How hard is it to remove filtration soils?
That depends on the extent or degree of the filtration soil and how long it has gone untreated. As a rule, you should never promise to remove filtration soils 100%. In most situations, you can remove a majority of the soils, but some cannot be removed safely.
Before treating filtration lines on nylon carpet, you must speak to the customer about the risk of color loss if there’s been long-term exposure to filtration soils. This color loss in nylon is called “fume fading.” Many of the pollutants trapped and filtered by the carpet fibers are gases commonly found in our indoor environment like car exhaust, jet fuel exhaust and gases created by cooking, heating, etc. Nitrogen oxides are commonly found in these environmental pollutants. When trapped in nylon fibers by oily soils, these oxides can start to breakdown the acid dye system often used for nylon carpet, oxidizing the color (bleaching). Unfortunately, in many cases, you cannot see the color loss prior to the cleaning, due to the heavy filtration soil.
If you have tried to remove oils or oily soils from carpet fiber, then you know your normal cleaning solutions are not completely effective – you have to pull out a specialized solution to break the oils’ bond with the fibers. Filtration soils are the same, you need to choose a solution that is focused on the ability to suspend normal soils but can also break the bond that oils have with the fibers.
Here’s the process to remove filtration lines:
Pre-vacuum all carpets.
Apply Prochem Filter Out to filtration soil (Prochem Filter Out contains an amphoteric surfactant that is used for breaking these soils loose from the fibers, liberating the oils and allowing them to be rinsed away).
Agitate aggressively with brush (Caution: fiber distortion is possible if you get too aggressive).
Rinse and extract with Prochem All Fiber Rinse using a specialized crevice tool or an upholstery tool - a must! (Once you use your upholstery tool for filtration soils, NEVER use it on upholstery again, the pins in the tack strip will nick and burr your cleaning tool which can cause snagging when cleaning upholstery.) Your normal carpet wand will not work on filtration lines, as it cannot focus the solution nor does it have the concentrated vacuum required.
Clean area with your normal extraction cleaning process as you clean the rest of the room.
What should you charge?
That depends on you and your customer. This is not considered a normal soil or soil load, and most cleaners will charge a fee for attempting to remove these lines
Things to remember:
Know what the soil is and why it's so resistant to cleaning.
Have the correct cleaning solutions and tools.
Most of all, remember this: When it comes to filtration soils and removing them successfully, “Under Promise and Over Deliver”!