Keeping restaurant carpets clean presents some interesting challenges. Cleaning must factor in foot traffic, airborne grease and oil and liquid and food spills.
A first step to keeping restaurant carpets clean and healthy is vacuuming. While a vacuum cleaner may not be able to remove particulates of grease and oil that have settled into carpets, the bulk of soil in a carpet is dry soil such as dust, dirt, and food crumbs. High-performing and effective vacuum cleaners are designed to remove a great deal of this dry soil, preventing it from damaging carpet fibers, helping to keep the carpet clean and healthy, and even extending the life of the carpet.
For deeper cleaning, managers should understand the four fundamentals of carpet cleaning and soil removal, often referred to as TACT:
C: Chemicals used to clean carpets
T: Time necessary for the chemicals to dissolve and loosen soils
All four components of TACT are essential to suspension, the process of loosening soils on a surface or a carpet fiber so that it can be removed using a mechanical device such as a hot-water extractor. To see how soil suspension and TACT are interconnected, it might help to examine what goes on behind the scenes when carpets are extracted.
The cleaning process
After vacuuming to remove dry soils, carpet cleaning technicians typically spray the carpets with a chemical, the C in TACT. This process is referred to as “prespraying” the carpets and is the first step in soil suspension. A number of different types of chemicals used to prespray carpets, and some are enzymatic. An enzymatic prespray is designed to actually eat soils. Because the soiling of a restaurant carpet may contain proteins from food spills, bacteria, grease and oil, an enzymatic cleaner can be an effective chemical to employ.
Next, the chemical will need time to be effective, which brings us to the T in TACT. Most cleaning chemicals need several minutes to start dissolving soils. For this reason, the technician typically presprays a large area of the carpet before taking any further carpet cleaning steps. Some green-certified chemicals may need more time to “dwell” on carpets than conventional cleaners, and an enzymatic prespray may take far longer. Depending on the extensiveness of the protein soiling, an enzymatic cleaner may need to dwell on a carpet for one or more hours to work effectively.
The next step in soil suspension involves agitation, the A in TACT. To understand agitation, picture hand washing. Even with soap allowed to dwell for a few seconds, to really loosen and rinse away soils requires some type of agitation, rubbing the two hands together. The same is true when cleaning carpets.
There are different ways technicians agitate carpets to remove soils. One way is to utilize a 175-rpm rotary machine with a shampoo brush attached. With an effective chemical applied and allowed the designated time to dwell on the carpet, this is one way to suspend soils from carpets. However, a more effective way is for the technician to use the wand of the extractor along with the pressure generated by the hot-water extractor, measured as pounds per square inch (psi), to agitate the carpets.
Some extractors have an adjustable pressure setting, with a lower setting used for delicate or lightly soiled fabrics and a higher setting used for more heavily soiled fabrics and carpets. The higher pressure deposits more water into the carpet, which may require more dry (vacuum) strokes to remove the water. However, the entire process agitates the carpet to help remove soils. Further, the dry strokes are important because they not only help agitate the carpet, they remove moisture and soil, leaving the carpet as dry as possible. This helps prevent resoiling, which can happen while the carpet is still wet, and allows the carpeted area to be available for use as quickly as possible.
The final fundamental to discuss is the last T in TACT, referring to temperature or heat. It is so critical to effective carpet cleaning, it warrants its own subheading. When discussing the importance of heat in cleaning carpets, instructors often refer to the Arrhenius Law, a formula first developed in the 1880s by Swedish scientist Svante Arrhenius. He found that chemical activity doubles with each 18° increase in heat starting at 118°F F).
In other words, the effectiveness of carpet cleaning chemicals improves every 18° above 118°. This is why some hot-water extractor manufacturers design their machines so that the water/solution released at the wand tip is 212°F. The added heat not only improves the effectiveness of the cleaning chemicals, it produces greater soil suspension, which allows the hot-water extractor to more effectively remove soils from carpet fibers, resulting in more effective cleaning.
Speeding up drying time when cleaning carpets can be so important to the carpet cleaning process it might be considered the “fifth fundamental.” A carpet, especially in a restaurant setting, must dry as quickly as possible. Still-wet carpets can be slippery to walk on and make transition areas—going from a carpeted area to a hard-surface floor—dangerous.
In addition, as referenced earlier, a wet carpet can act as a magnet, attracting more soils to it, called resoiling. Even worse, a carpet that takes more than 48 hours to dry raises the potential for mold and mildew to develop. This can be serious and in some cases addressed only by replacing the carpet.
To prevent this, the technician must perform enough dry strokes over the carpet to remove excess moisture. In addition, it helps to place fans throughout the carpeted area blowing not on the carpets but slightly above them. Following these steps, the carpets should dry in a few hours—cleaner, healthier, and ready for service.
Mark Baxter has been involved with the professional carpet cleaning industry for more than a decade and is now an engineer and product manager with U.S. Products, a professional carpet cleaning equipment producer.