There are several carpet cleaning methods being used by various professional carpet cleaning companies and households today. Each type of cleaning has its own peculiar advantages and disadvantages. This article will assist you to choose among them, as we tabulate the most popular methods, and outline their perceived pros and cons.
Basically, carpet cleaning methods may be placed in one of two categories: wet cleaning, or dry cleaning. Wet cleaning includes hot water extraction and also cleaning with an absorbent pad. Dry carpet cleaning involves the use of chemical powders or foams applied by special machines with counter rotating brushes, pads or cylinders.
(a) Hot Water Extraction Or Deep Steam Cleaning
The carpet is first pre-conditioned with a chemical reagent in order to saponify or liquefy soils and oil based substances which may be present. Water at a temperature near its boiling point and a pressure of 50 to 500 psig is then injected into the carpet and after a suitable dwell time (usually 10 to 15 minutes), the resulting solution is extracted with a vacuum of 5 to 14 inches HG.
- Gets out soiling from deep down in the carpet.
- Allows the use of high temperatures, pressures and chemical concentrates.
- Permits extended dwell times for reaction of cleaning solvents.
- Chemical reactivity facilitated by agitation with grooming tool or extraction wand.
- This is the method most widely recommended by carpet manufacturers and industry cleaning experts and professionals.
- Relatively long drying time. This can be reduced with the use of powerful equipment by competent technicians
- Expensive equipment usually required for maximum efficiency
- Relatively high cost factors
(b) Cleaning With An Absorbent Pad
This method which is commonly known as bonnet cleaning, is most often used for routine light maintenance, but it is also used for regular carpet cleaning. The carpet is first vacuumed, and then a chemical solution is sprayed unto it with a hand pump or electric sprayer. The solution is allowed to stay on the carpet for a suitable dwell or reaction time. The absorbent pad or bonnet, which looks like a towel, is placed on the drive block of a rotary floor machine and spun over the carpet surface at 100 to 300 rpm. This action serves to impregnate the carpet fibers with the chemical solution and then pick it up with the soils afterwards.
- Fast. Simple. Inexpensive.
- Excellent results with lightly soiled carpets.
- Only cleans the top one-third of the carpet fibers. Incapable of reaching deeper down.
- Leaves dirt and chemicals to accumulate at the bottom of the carpet fibers near to the backing.
(a) Cleaning With An Absorbent Compound
A powder which has been mixed with special solvents and cleaning agents, is spread over the carpet and worked into the fibers with a special machine fitted with counter rotating brushes. The powder absorbs the soils and is allowed to set on the carpet for 10 to 15 minutes and then vacuumed up.
- Very simple system. No special technical training required.
- Very fast drying. About 20 minutes required before the carpet can be back in service.
- Powder may be trapped in plush pile carpets and left to build up over time.
- Usually causes excessive dust in the interior environment.
- Unable to clean deep down into the carpet
(b) Dry Foam or Rotary Shampoo Method
A foaming surfactant is applied to the carpet to engender solution or suspension of soils, and it is then whipped into a foam and worked into the carpet fibers with the rotating brushes of a special machine. After a short dwell time, the foam is extracted with a vacuum.
- Fast. Simple to apply. Inexpensive.
- Excellent agitation with these rotating brushes.
- Small amount of moisture allows fast drying of carpet.
- Unable to achieve thorough soil extraction below the surface of the carpet.
- High temperatures usually not achieved.
- Excessive wetting possible with equipment malfunction.
- Brushes may cause damage to carpet fibers, especially when new.
You will be well advised to review these pros and cons before deciding which method you would like to be used to clean your carpet.