The cleaning effect of water is known by all. In fluid form, water reaches all areas, both in recesses and cavities and it wets all surface contaminants. Even today, cleaning with aqueous solutions is still the most commonly used method and water-based alkaline cleaners are the most popular.
Cleaners in form of chemically-active aqueous solutions
Saponification in these cases is not normally of importance. In the forefront are physical and colloidal processes such as adsorption and desorption, particle attraction and repulsion, and the creation and collapse of emulsions, whereby active cleaning substances or so-called surface-active and boundary layer interactive substances are the key to the cleaning effect.
A major group of these substances are ionogenic compounds which become active in aqueous solutions. The negative particles in these solutions, the anions (and therefore the term anion-active), tend to gather on contaminated surfaces and negatively charge the dirt particles. As the metal’s surface is also negatively charged, the dirt particles or contamination are repelled.
The fact that the anions and the dirt particles are similarly charged is not the only decisive factor. Silicates and phosphates can form relatively large polymer ions in aqueous solutions. Compared to smaller ions, these have the advantage that they can keep detached and water-insoluble dirt particles in the cleaning fluid in colloidal suspension. This means that the dirt particles are so finely distributed that they cannot settle back on the cleaned surface.
Cleaners in the form of purely physically-active organic solvents
Apart from inorganic substances, today’s industrial cleaners also contain organic, surface-active substances. These are characterized by their saponaceous properties, whereby their disadvantages (such as deposits in hard water) are inactivated and today they are contained in nearly all industrial cleaners and detergents.
The molecules of the surface-active substances (generally referred to as tensides) combine properties which are normally found in various substances and apparently mutually complement each other.
According to the principle “like dissolves like”, a substance will only dissolve in a similar medium. Most substances are either dissolved in water or in oil.
In the case of tensides, both characteristics are combined in one molecule. Tensides consist of a hydrophilic (water attracting) and a hydrophobic (water repelling) part. As a result they are both water-soluble and oil-soluble and display particular “hybrid” characteristics. In aqueous solutions, tensides are highly effective even in very small quantities. Physically, this can be explained by the tendency of tensides to mainly accumulate on boundary surfaces and which are therefore sometimes present in high concentrations.
The inclusion of such compounds accounts for the high effectivity of today’s cleaners. The tensides lower surface tension so that the cleaning solution can better wet and penetrate all dirt and contaminants than pure water and even penetrate cracks and cavities. Tenside molecules facilitate the removal of dirt particles and thus increase the cleaning effect.
At certain solution concentrations, they create molecule groups (so-called micelles) which assist the previously mentioned processes. They can also disperse or emulsify non-water soluble substances such as oils and greases.
Today’s industrial cleaners contain an optimum and effective combination of inorganic, ionic and nonionic substances. The effectiveness of these cleaners is based on various and carefully matched physical and chemical interactions.
Product portfolio of FUCHS cleaners
- Neutral cleaner
- 1-Component products
- Builder + surfactants
- System cleaner
- Special products
- Water-based corrosion protection
- Maintenance cleaner
- Personal Care
Find the right product for your application with the FUCHS > product assistant.
In addition to the cleaning system and the cleaner used, the cleaning container plays a crucial role. Inform yourself about the fundamental principles for optimally-designed cleaning racks.