Cleaning carpets efficiently andeconomically using modern methods
Maintenance cleaning
Maintenance cleaning generally involves vacuuming with a canister or brush-type vacuum cleaner; but a vacuum sweeper equipped with an antistatic carpet roller brush may also be used. The decision on the type of machine to be used depends on the amount of soil that is carried into the building every day, the type of carpet and the size of the area.
Apart from the size of the area to be cleaned and the carpet’s surface structure, the most important factor for choosing the right vacuum cleaner is its performance. In many cases only the fan motor’s wattage is used for this assessment, but it is by no means the sole criterion for a high cleaning performance. Also important are the vacuum in millibars/kilopascals (mba/kPa) and the air flow rate in litres/second (l/s). Typical values for professional machines are a vacuum of between 210/21 and 250/25 mba/kPa and an air flow rate of 50 to 70 l/s.
In order to achieve high suction power it is also important to pay attention to the quality of the accessories. Only a floor tool that makes good contact with the carpet’s fibres can maintain the required vacuum, i.e. the floor tool follows the operator’s movements. This is accomplished only with the right type of joint or joints on the suction tube connection to the floor tool. The weight of the floor tool also plays an important part here. A metal glider is an advantage in this respect.
An agitator brush system should be chosen for long pile carpets (looped pile or plush) and where the rate of soiling is high because the roller brush reaches deep down to the bottom of the carpet pile and thus dislodges the more stubborn particles of dirt, threads and hairs. The air stream picks up the particles dislodged by brushing and conveys them into the dust bag. The added mechanical action greatly improves the results achieved and also the appearance of the carpet since the pile is freshened up at the same time.
More recently, double roller brush systems have appeared in the market for larger areas. They feature contra-rotating brushes and have the additional advantage of producing a shadow-free appearance (without a zebra pattern) – irrespective of whether they are used forwards or backwards. This is particularly important on velour/plush carpets
Stain Removal
Stain removal is an essential part of maintenance cleaning. The principle here is to remove spots and stains on the day they occur. This is generally accomplished with the aid of an all-round stain remover, which is sprayed onto the stain and, after waiting a brief period, dabbed with a light-coloured absorbent cloth. Care must be taken to ensure that the stain is not rubbed deeper into the carpet or made bigger. It is also advisable to first check the colour fastness of the carpet in an inconspicuous place because the stain remover normally contains a small proportion of solvent. On long-pile carpets, a shoe brush can be used to dab the sprayed-on stain remover deeper into the pile to dissolve the dirt there too.
An alternative to stain removal with the vacuum/dabbing method is the so-called rinsing method. In this process the stain is sprayed with stain remover and, after the required reaction time, rinsed with water and vacuumed away with the hand tool of a spray extractor. The procedure may be repeated as required and thus ensured that no residue of the stain remover is left in the carpet.
Selecting Vacuum
When selecting the vacuum the following points should be considered
– Size,
– Waste container capacity,
– Weight,
– Sound level,
– Handling,
– Radius of action (length of power cord, hose, suction tube, hybrid or battery unit),
– Accessory holder,
– Filter retention rate and Hybrid unit.
It is important to make sure the filter or dust bag in the waste container has the space it needs to make full use of its capacity and thus accommodate the amount of dust and dirt for which it is rated. Fleece filter technology in particular has proven to be very efficient in this respect because – owing to its three-dimensional structure – it does not become plugged with fine dust particles as quickly as conventional filter bags and thus guarantees a uniform air flow. The dirt picked up is therefore deposited reliably in the filter bag right up to the limits of its capacity. As a result, the consumption of filter bags is reduced by about 50%. In addition to the very remarkable retention rate (99.99%), the high tear resistance is another advantage. Viewed overall, this makes it more economical.
Economy of operation is also influenced by choosing a specific type of vacuum cleaner. Backpack vacuums, for example, are highly efficient in cramped conditions or areas with a lot of furniture. Since the operator carries the vacuum, cleaning operations can often be shortened by up to about 20%: The operator is able to move more freely and faster and concentrate fully on the cleaning task.
So-called hybrid vacuums have proven to be ideal for in-between cleanups e.g. for cleaning small quantities of soil where there is public traffic in lobbies and reception areas. Such vacuums can operate in the cordless, battery-powered mode, but with reduced suction power. They achieve full suction power as soon as they are connected to the mains power supply.
Interim cleaning
Interim cleaning process brings about an optical improvement of the carpet surface. It is used in order to extend the time intervals between deep cleaning operations or to remove traffic marks in corridors or other areas where traffic is heavy, e.g. in front of lifts.
Apart from the methods used up to now (dry foam, powder, yarn pad or micofibre pad cleaning), there is now a new method on the market which employs encapsulation technology. It is characterised by its very simple application, efficient deep cleaning action, minimal detergent residue thus reducing the rate of subsequent soiling and short drying times. The cleaned floors can be used again very quickly. This method is therefore recommended for use in hotels, restaurants and office buildings in particular. Roller brush systems running at speeds of up to 500rpm have proven very successful for applying the special cleaning agent (6% solution). Soil particles in the carpet fibres are surrounded by the cleaning agent, their bonding force is neutralised in the process and, once dried, the dirt can be easily picked up. A brush-type vacuum should be used for this purpose.
In view of the low quantity of cleaning agent used (0.05-0.25 l/m²) only a very short drying time is required. It is between 20 and 120 minutes, depending on the quantity applied, its distribution over the carpet and climatic conditions.
It is particularly economical to work in the cleaning agent in the evening. After drying overnight, the encapsulated soil can be vacuumed away the next day in the course of routine maintenance cleaning preferably with a brush-type vacuum cleaner.
Deep cleaning
Deep cleaning is carried out at extended intervals and enables all soiling to be removed that has accumulated over time despite regular and thorough maintenance cleaning. This refers primarily to dirt that has collected deep down in the pile or has stuck to the pile.
At present, only wet processes can be used for deep cleaning. There are therefore certain quality requirements that the carpet has to meet in respect of material, structure and how it is laid. It is also necessary to take into account the appropriate drying times. The carpet must be thoroughly vacuumed before wet cleaning. Any conspicuous stains must be treated in advance with a stain remover or wetted with the cleaning solution using a hand tool (optional accessory for the machine being used) or a sprayer. Wet cleaning is only suitable for moisture resistant carpets. This also applies to the carrier fabric and the adhesive.
Depending on the degree of soiling, the best known wet cleaning methods are:
– Spray extraction using single-step method
– Spray extraction using two-step method
– Spray extraction with power washing brush
– Combination of wet shampooing and spray extraction with clean water.
Furthermore, the use of carpet cleaners with an integral brush and vacuum head is becoming more widespread. We differentiate between single and double roller brush heads. The brush heads are float-mounted so that they can adjust to the type of carpet and depth of pile.
The single-step method is always used in order to avoid the carpet being soaked. The cleaning solution (mixed in a strength that suits the degree of soiling) is sprayed onto the roller brush by an integral pump and then worked into the carpet. In this process the cleaning solution makes contact with the dirt on the fibres, the bonding forces are neutralised and the dirt expands. As a result of the additional mechanical action of the brush, even heavy particles of dirt are brought up from the bottom of the pile and conveyed to the recovery tank together with the soil already dislodged from the fibres. Cleaning is performed one section at a time. The contact pressure produced by the brush head with integral vacuum ensures that only a minimum of residual moisture remains in the carpet. It is essential to perform a clear rinse using the same method in order to avoid subsequent soiling due to cleaning agent residue.
Machines with a higher capacity tank and double (contra-rotating) roller brush systems, which can be either pushed or pulled, are used for larger areas. For reasons of economy, a battery-powered carpet cleaner, which is operated like a scrubber-dryer, should be used for cleaning areas of more than 1,000sqmt.
Anotherproduct is available to dry the floor even faster: a powerful air blower. It can increase the speed of drying by up to 50%. It is important to ensure adequate ventilation during this process.
The deep- cleaned carpet must not be walked on until it is completely dry. It should be thoroughly vacuumed before it is walked on or furniture is moved back into the room in order to pickup any existing residue of cleaning agent. Carpets cleaned in the way described above have their original colour and structure restored and thus contribute quite considerably to the favourable image of the building.
Gerd Heidrich, Karcher, Primary publication
in “rationell reinigen” magazine/Germany
and Niels W. Buhrke Freelance Journalist
