REMOVE: Remove soil, stain, or deposit through a cleaning process.
ADD: Add a finish or film to enhance appearance, protect a surface, add properties such as softness, slip, release or repellency.
CHANGE: Color, texture, odor, etc.
OTHER: De-foam, deice, make foam, etc.
Cleaning is simply the act of removing an unwanted material from a surface. Here are several basis processes to clean a surface
Inorganic soils contain salts and materials that are water-soluble. When rinsed with water they dissolve in the water are carried away. Water is one of our most powerful cleaning agents. We simply add ingredients to aid and enhance water’s natural abilities.
Most organic soils are soluble in organic solvents such as alcohol, glycol ethers, and mineral spirits. Here the soils dissolve in the solvent and are carried away from the surface.
Inorganic soils also contain insoluble minerals: dry dirt. They can have a range of particle sizes from small grains to fine silt and clays. Cleaning solutions can give these particles an electrostatic charge. The particles then repel each other and do not aggregate or floc together. They stay suspended and dispersed in the rinse water as they are removed from the surface.
Organic soils that are not water-soluble can be made to suspend in water by creating an emulsion, which is made up tiny droplets covered with a shell of surfactant. Here too the charge on the droplets prevents aggregation. The tighter the particle or better the emulsion at this stage, the more difficult it will be break the soil out in the water treatment process.
Animal and vegetable oils contain naturally occurring amino acids. When they come in contact with a caustic or a highly alkaline cleaning solution the caustic reacts with the acid to form a soap. That soap is usually water-soluble and is removed they by the solution function. Petroleum oils do not saponify. They must be emulsified.
If the soil is alkaline or acidic it can be changed or removed by first neutralizing the soil. Then the appropriate removal system can be applied depending on the nature of the neutralized deposit. Removing the high or low pH may be sufficient to render the surface usable.
Acidic cleaners react with and make soluble hard water scale and other carbonates, rusts and oxide deposits. Stronger acids can react with and remove the metal under a soil thus lifting out the soil. Caustic can react with and under cut soils on aluminum surfaces.
Some soils or stains can be altered with bleach or cleaners containing bleach to be visually acceptable without actual or complete soil removal.
Some materials absorb, and remove unwanted soils in tact.
POST CLEANING CONSIDERATIONS
In each cleaning process you transfer soil from a surface to a cleaning solution. You then have created another cleaning issue: how to clean the solution. The soils you removed do not go away.
From simple floor cleaning with a mop to a ten stage metal cleaning and finishing line you will ultimately need to consider in impact the removed soil will have on the waste water treatment system. There are as many opportunities in this part of the plant an in the initial cleaning operation.