Extending the Longevity of Carpet
- By Bill Yeadon
- March 1st, 1999
Today’s college and university facility interiors bear little resemblance to those of the past. State-of-the-art technology in the 1950s was an overhead projector. The floors were made of wood, tile or terrazzo and were hot in the summer and cold in the winter. The noise level, especially in hallways, could be deafening. Professors became fatigued from standing on the hard surfaces. The maintenance people, or janitors, as they were known then, were always sweeping, buffing or waxing those long, shiny hallways. Carpet had yet to make the transition from our homes to general institutional use.
The oil crisis of the mid-70s forced architects and interior designers to rethink the way facilities were built. One of the changes that came about was the increasing use of carpet instead of hard surface. The carpet industry during that period was producing less than one-half billion yards of carpet a year. Today, annual production of carpet exceeds 1.5 billion yards, with one-third going into commercial facilities.
While carpet has proven beneficial in many ways, such as aesthetics, comfort, lower noise levels and less chemical emissions, maintenance has been a challenge for those schooled in hard surface maintenance.
Unlike hard surfaces, on which most soiling and spills are handled the same, carpet responds differently depending on the fiber content. The two dominant fibers in commercial carpet are nylon and polypropylene (olefin). Nylon is best suited for most applications because of its resilience, dye capabilities and ease of cleaning. The one drawback is its affinity for acid-based fruit drinks, such as Kool-Aid and red punch. Nylon can be solution-dyed to improve its resistance to strong cleaning agents, although it still can be damaged by bleach. Polypropylene is popular for its low cost and for its ability to withstand bleach and most staining materials. The fiber’s drawback is its poor resilience, which makes it a poor choice in high-traffic areas. The other negative is its affinity for oily soil, such as asphalt.
A new fiber is now poised to grab market share from both nylon and polypropylene. According to developer Shell Oil, Corterra has the resilience of nylon and the stain resistance of polyester. If these claims are true, carpet maintenance will be much simpler in the future.
Walkoff mats. Regardless of which fiber has been used to manufacture the carpet, a good maintenance program begins with preventive maintenance. Walkoff mats at all entrances can trap up to 80 percent of all tracked-in soil and create significant cost savings. According to the International Sanitary Supply Association (ISSA), the cost for removing one pound of soil from a building is $500.
Vacuuming. The next step in a proper maintenance program is dry soil removal, or vacuuming. Up to 79 percent of soil consists of insoluble dry particles and is most effectively removed by dry vacuuming. One important component of the vacuum is the type of bag used. A high-efficiency type bag that traps particulate soil down to the one-micron size is effective in reducing dust burdens as well as improving the indoor air quality.
Spot removal. A spotting program should be implemented in order to prevent spots from becoming stains. When selecting carpet, a moisture-impermeable backing, such as vinyl-backed carpet, facilitates spot removal. While a normal backing is affected by excess moisture, a moisture barrier allows the cleaning technician to flush the contaminants thoroughly from the fiber with little chance of carpet delamination.
Interim cleaning. When soil levels have reached a point where vacuuming is not as effective, interim cleaning is needed. Interim methods, such as absorbent compounds, dry foam extraction or absorbent pads (bonnet), can be used to keep the carpet at an acceptable appearance level.
Absorbent compounds consist of a cellulose- or a porous synthetic polymer-based material. The compound is saturated with detergents and solvents in a pH range of slightly acidic to alkaline. The material is spread by hand or is mechanically applied and then agitated into the carpet pile. After sufficient dwell time, the compound is extracted using a vacuum cleaner. The benefits of this type of system are enormous: minimal drying time, few wicking problems and ease of technician training.
Dry foam extraction applies a high-foaming detergent through a dry foam machine. The machine uses reel-type brush action for agitation, followed immediately by extraction through the machine or a wet vacuum. The benefits of this system are minimal drying time as well as high production levels, depending on the size of the machine.
The absorbent pad, or bonnet method, is a popular interim cleaning method for commercial carpet. A detergent emulsified in either a dry solvent-based or carbonated or noncarbonated water-based carrier is sprayed onto the carpet and the bonnet. The bonnet is attached to a drive block on a rotary machine that provides the agitation and the extraction. This is a minimal moisture system that accomplishes high productivity; however, it should not be used as a restorative method. The technician must provide adequate lubrication of the fibers in order to avoid textural damage.
Restorative cleaning. The oldest method of cleaning is rotary shampoo. A high-foaming detergent is applied to the carpet through a shower-fed, rotating, nylon-bristled brush. For optimal results, this should always be followed by extraction using a wet vac or wet extraction machine. Rotary shampoo is considered to be a restorative cleaning method and can accomplish high productivity. As with the bonnet cleaning method, adequate carpet lubrication will prevent texture damage.
The method considered to be the most effective in restorative cleaning is hot water extraction. Several types of machines, including portable, van-mounted or walk-behind units, are available. This method uses a preconditioner, which is applied to the carpet with a pressure sprayer and is allowed to dwell for 10 to 15 minutes. In heavy soiling conditions, agitation should be accomplished by hand or mechanical brushing. This is followed by use of a hot water extraction machine to flush the suspended soil from the fibers. This method requires thorough training of the technician to prevent overwetting of the carpet.
Regardless of the method chosen, the most important issue is a well-planned maintenance program. The formulation and implementation of this plan keeps the appearance level high and prolongs the life of the carpet.
Bill Yeadon is CEO of the International Society of Cleaning Technicians (ISCT) in Montvale, N.J., and a partner in The Cavalry II, an Indianapolis-based consulting firm serving the carpet manufacturing and cleaning industries.