The basic scientific principles of effective cleaning can be divided into four major steps: dry soil removal, soil suspension, soil extraction, and drying.
Principle 1: Dry Soil Removal (Vacuuming) - Dry soil removal is accomplished in phases:
•Overall vacuuming with an approved SOA/GL commercial vacuum cleaner.
•Concentrated entry area vacuuming (removal of the destructive build-up of abrasive soil).
•Removing dry soil from carpet can be accomplished using different types of vacuum cleaners. Due to the fact that 79% or more of the soil can be removed dry by vacuuming, vacuuming frequency schedules should be developed and added to total carpet care maintenance programs (Reference Figure 2).
Principle 2: Soil Suspension – Once dry soil has been removed from the carpet, soil suspension (preconditioning) procedures begin. Soil suspension and removal are the most critical steps in effective carpet cleaning. The goal of soil suspension is to separate soil from fiber surfaces. There are four fundamental activities to be accomplished under the soil suspension principle. These are chemical action, elevated temperature (heat), agitation, and time.
Chemical action is employed in two phases of the cleaning process.
•In the first phase, cleaning solutions, or compounds, are used to prepare the carpet for cleaning by reducing surface tension and dissolving various soils. This step, called “preconditioning,” is essential. It is unreasonable to suggest that soils, which have been ground into carpet, along with oils that have had time to oxidize or dry out, could be suspended adequately in the few seconds that elapse between detergent application and the removal phases employed in the any deep cleaning method.
•The second phase of chemical activity occurs when cleaning solutions, or compounds, are mixed or metered into rinse solutions to suspend light soils that accumulate in non-traffic areas, along baseboards, or under furniture. Therefore, solutions properly formulated, and/or diluted (per labeled instructions) and applied during preconditioning are essential for full effective cleaning.
NOTE: Take precaution not to overspray preconditioners onto furniture, baseboards, and doors. Wipe down the areas immediately after as necessary.
Elevated Temperature (Heat) – Heat reduces the surface tension of water, and enables faster, more efficient cleaning than cold water. It is merely a matter of thermodynamics, or the ability of heat to accelerate the molecular activity of the solutions employed and thus aid in separation of unwanted matter from fibers.
Agitation – Agitation in some form is required to accomplish uniform solution penetration and distribution. Without agitation, soil suspension tends to be non-uniform which is often indicated by soil streaks following the removal process. Agitation, using a common, multi-bristled brush to work in pre-conditioner solutions is more effective and time-efficient. Mechanical agitation involves the use of mechanized, counter rotational brush (CRB) action to achieve aggressive agitation and distribution of preconditioning solutions into the carpet pile.
Time – The fourth fundamental, time, is often the least considered. Soils deposited and compacted over extended periods between cleanings take time to dissolve and become suspended. SOA-approved cleaning solutions may require prolonged contact or “dwell time” for adequate fiber penetration and soil suspension to occur. Based on the formulation and application temperature, dwell time can vary. Follow manufacturer’s label instructions in these instances.
Principle 3: Soil Removal – Soil is an unwanted substance that is foreign to the construction of the carpet. In order to achieve a state of effective cleaning, suspended soils must be extracted (wet or dry) physically from the pile by suspending, dissolving, encapsulating, or adsorption/absorption.
Principle 4: Drying – Cleaning is not complete until carpet is dry and ready to be trafficked.
•First, it is required to return the carpet to use by end-users as soon as possible.
•Second, drying carpet essentially eliminates slip-fall hazards, especially in areas where carpet transitions to hard surfaces.
•Third, supply natural or mechanical ventilation during the cleaning and drying phases of deep cleaning.
Fourth, adequate ventilation is recommended to speed up drying time. The use of commercial air movers (drying fans), HVAC handling systems, or dehumidifiers greatly reduce drying time.