Powerful dirt removal without detergents
Steam cleaners have been used in many households for the past 15 years and more. Steam cleaning has also become a firmly established method in restaurant kitchens and restoration workshops. And jets of steam have been used to remove oily and greasy dirt from vehicle engines for nearly 60 years. Yet despite its versatility there is widespread ignorance of the principles of how steam works.
According to test findings by cleaning specialist Kärcher’s research and preliminary development department, three factors play a decisive role: the steam jet’s mechanical effect and high temperature and the condensation of steam particles as they hit a surface.
The mechanical energy of the jet of steam emitted by the steam cleaner is generated by excess pressure in the boiler at a temperature of up to 140ºC. The jet hits the surface to be cleaned at a speed of up to 50 metres per second (180 km/h) and thereby overcomes the adhesive power of any dirt.
Temperature is another critical factor for producing a good cleaning result with a steam cleaner. The higher the temperature, the lower the mechanical energy required for dislodging dirt. Moreover, when the steam collides with the surface and the dirt, the two heat up at different rates. These thermal strains loosen the bond between surface and dirt.
Lastly, steam has a similar action to tap water softened with tensides. Its microscopic particles penetrate beneath the dirt and, unlike a brush, into small pores that even brushes and small-diameter fibres cannot reach. As steam condenses there, it instantly overrides the electrodynamic action of the dirt and dislodges it.
With these characteristics, steam cleaning has many advantages for the user. It does away with the need for detergents, which is especially good news for people with sensitive skin and/or allergies. Steam is a general-purpose medium, so there is no longer any need for the special cleaning agents kept many households for particular applications. Because steam cleaners always use fresh water, they are more hygienic than scrubbing brushes and buckets. What is more, the cleaned surfaces are very soon ready for use again because hot steam is not very wet and dries quickly. One important additional application is ironing. Steam at a pressure of up to 4 bar penetrates through even multilayered or heavy material and smoothes it with one pass of the iron.
Stema cleaners in the mid to upper price segment guarantee an even steam pattern as they have a pressure controlled actuator in the boiler that reacts more quickly to drops in pressure. This technology is less prone to lime scale build-up and measures more accurately than temperature-controlled actuators. Steam cleaners made by quality manufacturers come with metal parts that are better protected against corrosion, secure and break-proof connections, and heat-resistant plastic. A safety valve through which excess steam can escape is fitted as standard. High-quality steam cleaners have an additional safety feature – a cap that cannot be opened while pressure remains in the boiler.