To understand what is needed to achieve effective cleaning, it is helpful to have a basic knowledge of soap and detergent chemistry.
Detergent [a detergent is a surfactant or a mixture of surfactants having "cleaning properties in dilute solutions”. Commonly, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water.]
a) Hydrophilic ~ inorganic, water loving [: compounds that have an affinity to water and are usually charged or have polar side groups to their structure that will attract water]
b) Lipophilic (Hydrophobic) ~ organic, water hating [: compounds that are repelled by water and are usually neutral (zero charge.)]
Surfactants have a polar group at one end (hydrophilic) and a non-polar group at the other end (lipophilic). The interaction of these two groups in water will reduce the surface tension of water. One end is inorganic and mixes with water, the other end is organic, and will dissolve other organic compounds; a detergent solution will dissolve both organic and inorganic soils
These terms have much to do with the structure of water itself. Water consists of two hydrogen atoms joined to one oxygen atom (H2O) all in a triangular pattern. The oxygen is negatively charged whilst the hydrogen end is positively charged. Thus, water molecules are actually attracted to each other and form hydrogen bonds.
Water is inorganic and anything that will mix with water is hydrophilic. Oil and anything that will mix with oil are hydrophobic, which is organic, so when water and oil are mixed they separate (See also Emulsion)
a) Soap refers to a liquid cleanser with a slightly acidic pH
b) Detergents usually contain surfactants (laundry or specialist cleaners) although most car wash concentrates contain detergents
How Soaps and Detergents Work
Effective cleaning requires three different types of energy;
1. Kinetic (agitation)
2.Chemical (surfactants and enzymes)
3. Reactivity (heat) these types of energy interact and should be in proper balance. Let's look at how they work together:
Warm or hot water melts fats and oils so that it is easier for the soap or detergent to dissolve the soil and pull it away into the rinse water.
Thermal energy (hot water) gets things cleaner along with mechanical energy (abrasion) and chemicals (surfactants and etc.); if you reduce the thermal energy you need to increase the other two to compensate. However there are some newer surfactants and enzymes that work in cold water
Let's assume we have oily, greasy soil. Water alone will not remove this soil. One important reason is that oil and grease present in soil repel the water molecules. Now let's add soap or detergent. The surfactant water-hating end is repelled by water but attracted to the oil in the soil. At the same time, the water-loving end is attracted to the water molecules.
These opposing forces loosen the soil and suspend it in the water. Warm or hot water helps dissolve grease and oil in soil. Kinetic energy, agitation or hand rubbing helps pull the soil free so it can be flush rinsed away
Alkali
An alkali is a soluble salt of an alkali metal like sodium or potassium. Originally, the alkalis used in soap making were obtained from the ashes of plants, but they are now made commercially. Today, the term alkali describes a substance that chemically is a base (the opposite of an acid) and that reacts with and neutralizes an acid.
The common alkalis used in soap making are sodium hydroxide (NaOH), also called caustic soda; and potassium hydroxide (KOH), and also called caustic potash
A product that has a pH 9-12 (low to moderate alkalinity) is a suitable cleaner for most detailing tasks, whereas pH 13-14 is too high. A product that has a pH 8 – 10 (low to moderate alkalinity) is a suitable cleaner for most finished leather detailing tasks, whereas pH 12-14 is too high
Amines
Monoethanolamide (MEA), Diethanolamides (DEA) and Triethanolamine (TEA) are used in cosmetics as "buffers" and "emulsifiers". That is to say, they help control a solution's pH balance (buffer) and they also help water-based and oil-based ingredients work together (emulsification, they also serve as anti-foaming agents.
Chelators
Are used in chemical analysis, as water softeners, and are ingredients in many commercial products. Citric acid is used to soften water in soaps and laundry detergents. Chelators are commonly used in industrial manufacturing as detergent additives, stabilizing agents, preservatives, and flavour and colour retainers. Ethylenediaminetetraacetic acid (EDTA) is one of the most popular. It is an agent that is capable of forming either four or six bonds with metal ions. EDTA is widely used for enhancing the cleaning power of detergents and soaps by forming chelates with the magnesium and calcium metals in hard water.
Catalyst
A catalyst works by lowering the activation energy for a reaction, thus dramatically increasing the rate of the reaction. As a result, products are formed faster and reactions reach their equilibrium state more rapidly. Most reaction rates are millions of times faster than those of comparable un-catalysed reactions. A catalysts is not consumed by the reactions they catalyse, nor do they alter the equilibrium of these reactions.
Controlling pH
Popular chemicals include sodium hydroxide a caustic metallic base. It is used in many industries, mostly as a strong chemical base in the manufacture of soaps and detergents; it is often used to increase the alkalinity of a mixture, or to neutralize acids
Chelators
Are used in chemical analysis, as water softeners, and are ingredients in many commercial products. Citric acid is used to soften water in soaps and laundry detergents. Chelators are commonly used in industrial manufacturing as detergent additives, stabilizing agents, preservatives, and flavour and colour retainers. Ethylenediaminetetra acetic acid (EDTA) is one of the most popular. It is an agent that is capable of forming either four or six bonds with metal ions. EDTA is widely used for enhancing the cleaning power of detergents and soaps by forming chelates with the magnesium and calcium metals in hard water.
Cloud Point
[: the cloud point of a non-ionic surfactant solution, is the temperature at which the mixture starts to phase separate and two phases appear, thus becoming cloudy]
The temperature at which a surfactant becomes insoluble in water; this becomes important when designing detergents for use in hot water
Enzymes
[: are responsible for thousands of metabolic processes that sustain life. They are highly selective catalysts, greatly accelerating both the rate and specificity of metabolic chemical reactions]
Enzymes are proteins that catalyse (i.e., increase the rates of) chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzyme in order to occur at rates sufficient for life. Since enzymes are selective for their substrates and speed up only a few reactions from among many possibilities, the set of enzymes made in a cell determines which metabolic pathways occur in that cell.
Like all catalysts, enzymes work by lowering the activation energy for a reaction, thus dramatically increasing the rate of the reaction. As a result, products are formed faster and reactions reach their equilibrium state more rapidly. Most enzyme reaction rates are millions of times faster than those of comparable un-catalysed reactions. As with all catalysts, enzymes are not consumed by the reactions they catalyse, nor do they alter the equilibrium of these reactions.
Enzyme cleaners use chemicals naturally manufactured by plants and animals that cause chemical reactions that break down specific types of chemicals. An enzyme is a type of protein that can break up complex molecules into smaller pieces. Contrary to popular belief, enzymes are not living things. Enzyme activity can be affected by other molecules: decreased by inhibitors or increased by activators.
Many drugs and poisons are enzyme inhibitors. Activity is also affected by temperature (increases in temperatures speed up reactions and help the enzyme function and develop the end product even faster) pressure and chemical environment (i.e. pH)
Odour-causing bacteria are "food" for these micro-organisms that is consumed by the bio-enzymatic cleaners are converted into two basic compounds: carbon dioxide and water. Because enzymes only work on specific types of chemicals; proteins, lipids, sugars, enzyme cleaners must be matched to their purpose.
Enzyme cleaners work quickly by bio-degrading the stain, they will eliminate grease, oil, dirt, grime, vomit, urine, blood, coffee or food into its basic carbon, hydrogen or oxygen element, thereby eliminating the problem.
Enzyme cleaners are non-toxic and effective, they clean better than toxic and non-toxic detergents. Enzymes cleaners remove odours completely by breaking down the micro-particulates causing the odour. They are used mainly for carpet and upholstery cleaning. They will often remove tough stains and odours that other types of cleaners can’t. You can use different enzymes for different types of stains.
Different enzymes are suitable for different applications and fabrics. Lipase enzyme for example being more suitable as a degreaser, and others more general purpose or for removing particular dirt types such as the effect protease has on the protein molecules in food stuffs.
They have a particular lock and key action, which you may remember from biology lessons and they take a particular catalyst to start them off. In our case this is both heat reaching the 30/40 degree point, and the effect of the other ingredients as they dissolve to create a certain alkalinity level in the wash.
Biological vs non-biological detergents
Non Biological means it doesn’t contain enzymes, so the cleaning chemicals need to be harsher and usually rely on hot water. Biological cleaners can be used effectively at lower temperature and still be effective
Biological detergents clean in the same way as non-biological ones with additional effects from the enzymes, whose purpose is to break down protein, starches and fat in dirt and stains on clothing to be laundered, for example food stains, sweat and mud
Enzymes are naturally occurring proteins that boost complex reactions in a wide range of products. In the case of bio detergent, enzymes speed up and assist the other ingredients in your detergent when it meets your laundry in the washing machine.
Non-biological products do not contain enzymes, and as such, are generally favoured by those looking for a product that’s gentle on especially sensitive skin. However, it’s worth noting that bio detergents will always outperform non-bio detergents at lower temperatures, 30 to 50° C.
Emollients
Dishwashing detergents (Dawn, Cascade, Rinse Ad, etc.) contain emollients; an ingredient designed to protect a person's hands, by keeping them soft and prevent cracking and drying. However emollients make the paint surface more difficult to dry and leave an oily residue, this thin film, which also aids ‘sheeting’ from glassware.
The problem is that these emollients do not rinse away and you are left with a thin film on the vehicles paint surface, which will negatively impact product cross-linking and its durability. They also contain Diethanolamine, which act as foaming agents or as emulsifiers
Emollients have three basic properties:
1. Occlusion - providing a layer of oil on the surface of the skin to slow water loss and thus increase the moisture content,
2. Humectants (sheeting agent) - increasing the moisture-holding capacity of the stratum
3. Lubrication - adding slip to glide across the skin
Fats and Oils
The fats and oils used in soap making come from animal or plant sources. Each fat or oil is made up of a distinctive mixture of several different triglycerides. In a triglyceride molecule, three fatty acid molecules are attached to one molecule of glycerin. There are many types of triglycerides; each type consists of its own particular combination of fatty acids. Fatty acids are the components of fats and oils that are used in making soap.
They are weak acids composed of two parts: A carboxylic acid group consisting of one hydrogen (H) atom, two oxygen (O) atoms, and one carbon (C) atom, plus a hydrocarbon chain attached to the carboxylic acid group. Generally, it is made up of a long straight chain of carbon (C) atoms each carrying two hydrogen (H) atoms.
Optical Brightener
[: are dyes that absorb light in the ultraviolet and violet region (usually 340-370 nm) of the electromagnetic spectrum, and re-emit light in the blue region (typically 420-470 nm)]
Brighteners (Z)-Stilbene) is one of several different chemicals used and were once commonly added to laundry detergents to replace whitening agents removed during washing and to make the clothes appear cleaner. Optical brighteners have replaced bluing which was formerly used to produce the same effect. Some brighteners can cause allergic reactions when in contact with skin, depending on the individual.
These synthetic chemicals that make fabrics appear to glow in the presence of ultraviolet light; something that is really clean shouldn’t be an optical illusion; they don't have anything to do with getting things clean -- they're only added to detergents to make us think our laundry is brighter and whiter than it really is. These agents absorb ultraviolet light and emit it back as visible blue light.
Optical brighteners are actually ultraviolet dyes that may be invisible under many lighting conditions; for an optical brightener to work properly it must be exposed to ultraviolet light usually from sunlight; thus, they’re not of much value if the light falling on the treated surface is mainly incandescent (light bulbs).
There are additional potential problems with the use of optical brighteners; one of these is its tendency to yellow with age, which is one of the reasons that carpet and furniture manufacturers discourage its use. This chemical is not biodegradable and can pass through waste-water treatment plants and endanger aquatic plants and fish
Phosphates
Sodium tripolyphosphate (STPP) is an ingredient use to enhance the performance capabilities of automatic dishwasher detergents. They contribute buffering strength, sequestering (or chelating) power, dispersion and absorptive capabilities, and solubility. They not only strip food and grease from dishes but also prevent food debris becoming reattached during the wash. Phosphates are usually used as compounds of phosphate ions in combination with one or more common elements, such as sodium, calcium, potassium, and aluminium
Seventeen states banned phosphates from dishwasher detergents because the chemical compounds also pollute lakes, bays and streams as they create algae blooms and starve fish of oxygen.
Surfactants
Surfactants perform other important functions in cleaning, such as loosening, emulsifying (dispersing in water) and holding soil in suspension until it can be rinsed away. Surfactants can also provide alkalinity, which is useful in removing acidic soils. Surfactants are classified by their ionic (electrical charge) properties in water: anionic (negative charge), non-ionic (no charge), cationic (positive charge) and amphoteric (either positive or negative charge).
Many surfactants will adhere to a paint surface to enhance gloss or stop water spotting or because they see the paint protection product as rather similar in structure to the oils they like to bond with. Many products that contain surfactant will leave a film on the paint surface, which attracts water so masking any beading or sheeting.
Be cognizant that not all surfactants do the same thing, nor do they do it to the same degree. A surfactant is to all intents a ‘wetting agent’, which helps to evenly spread the product, different surfactants have different ability to wet surfaces. Beading and sheeting (hydrophobic and hydrophilic) are really just differences in hydrophobicity. A simplistic explanation of a surfactant is an emulsified oil, with very good adhesion.
Soap is an anionic surfactant. Other anionic as well as non-ionic surfactants are the main ingredients in today's detergents. The chemistry of surfactants- soaps are water-soluble sodium or potassium salts of fatty acids. Soaps are made from fats and oils, or their fatty acids
Sulphates
Sodium lauryl sulphate, sodium laureth sulphate, ammonium lauryl sulphate, ammonium laureth sulphate, TEA lauryl sulphate, and TEA laureth sulphate are collectively called sulphates; sulphates are surfactants, which create foam and suds
Water
The liquid solvent most commonly used for cleaning, has a property called surface tension. In the body of the water, each molecule is surrounded and attracted by other water molecules. However, at the surface, other water molecules only on the waterside surround those molecules. A tension is created as the water molecules at the surface are pulled into the body of the water. This tension causes water to bead up on surfaces (glass, fabric), which slows wetting of the surface and inhibits the cleaning process.
You can see surface tension at work by placing a drop of water onto a counter top. The drop will hold its shape and will not spread. In the cleaning process, surface tension must be reduced so water can spread and wet surfaces. Chemicals that are able to do this effectively are called surface-active agents, or surfactants. They are said to make water "wetter."
Water Temperature
Reactivity – [: the tendency of a substance to undergo chemical reaction and to release energy].
Warm or hot water melts fats and oils so that it is easier for the soap or detergent to dissolve the soil and pull it away into the rinse water. Thermal energy (hot water) gets things cleaner along with mechanical energy (abrasion) and chemicals (surfactants and etc.); if you reduce the thermal energy you need to increase the other two to compensate. However there are some newer surfactants and enzymes that work better in cold water. The temperature at which a surfactant becomes insoluble in water; this becomes important when designing detergents for use in hot water work at 85 O.F (30°C) or below.
How Water Hardness Affects Cleaning Action
Although soap is a good cleaning agent, its effectiveness is reduced when used in hard water. Hardness in water is caused by the presence of mineral salts - mostly those of calcium (Ca) and magnesium (Mg), but sometimes also iron (Fe) and manganese (Mn). The mineral salts react with soap to form an insoluble precipitate known as soap film or scum.
Soap film does not rinse away easily. It tends to remain behind and produces visible deposits on clothing and makes fabrics feel stiff. It also attaches to the insides of bathtubs, sinks and washing machines.
Some soap is used up by reacting with hard water minerals to form the film. This reduces the amount of soap available for cleaning. Even when clothes are washed in soft water, some hardness minerals are introduced by the soil on clothes. Soap molecules are not very versatile and cannot be adapted to today's variety of fibres, washing temperatures and water conditions.
I think this illustrates the importance of detailers understanding the ‘science’ of cleaning; and to this end it is helpful to have a basic knowledge of soap and detergent chemistry and what is needed to achieve effective cleaning
All Purpose Cleaner (APC)
An all-purpose cleaner (APC) (pH 9.5 – 12.5 dependent upon mfg.) is an aggressive, grease-cutting cleaner for engine compartments and wheels. It’s better to use a specific stain remover than to compromise. Always select a chemical / cleaner that are biodegradable, environmentally friendly and safe to use by observing any precautions recommended so that they won’t harm you, your vehicle or the environment
Many well-intentioned detailers use the so-called all-purpose cleaning (APC) chemical for detailing. Using a product like Simple Green or a degreaser to clean everything from wheels to carpets is both dangerous and harmful to the materials used for modern automobile materials. A safer alternate is a limonene (citrus-based) solvent, they are biodegradable, environmentally friendly and safe to use.
There is no such thing as a one size fits all type chemical cleaner, regardless of what a car care product vendor would have you believe.
Most detailing chemicals are formulated to remove specific stains and a little knowledge of their pH and chemical content will help in their correct selection and use; the most common types of chemicals include surfactants, solvents, wetting agents, Saponifiers and Chelators
How Soaps are made-
Soaps are mixtures of sodium or potassium salts of fatty acids, which can be derived from oils or fats by reacting them with an alkali (such as sodium or potassium hydroxide) in a process known as saponification.
Saponification of fats and oils is the most widely used soap making process. This method involves heating fats and oils and react them with a liquid alkali to produce soap and water (neat soap) plus glycerine.
The other major soap making process is the neutralization of fatty acids with an alkali. Fats and oils are hydrolysed (split) with a high-pressure steam to yield crude fatty acids and glycerine. The fatty acids are then purified by distillation and neutralized with an alkali to produce soap and water (neat soap).
When the alkali is sodium hydroxide, sodium soap is formed. Sodium soaps are "hard" soaps. When the alkali is potassium hydroxide, potassium soap is formed. Potassium soaps are softer and are found in some liquid hand soaps and shaving creams. The carboxylate end of the soap molecule is attracted to water. It is called the hydrophilic (water-loving) end. The hydrocarbon chain is attracted to oil and grease and repelled by water. It is known as the hydrophobic (water-hating) end.
How Water Hardness Affects Cleaning Action
Although soap is a good cleaning agent, its effectiveness is reduced when used in hard water. Hardness in water is caused by the presence of mineral salts - mostly those of calcium (Ca) and magnesium (Mg), but sometimes also irons (Fe) and manganese (Mn). The mineral salts react with soap to form an insoluble precipitate known as soap film or scum. Soap film does not rinse away easily. It tends to remain behind and produces visible deposits on clothing and makes fabrics feel stiff. It also attaches to the insides of bathtubs, sinks and washing machines.
Reacting with hard water minerals to form the film uses up some soap. This reduces the amount of soap available for cleaning. Even when clothes are washed in soft water, some hardness minerals are introduced by the soil on clothes. Soap molecules are not very versatile and cannot be adapted to today's variety of fibres, washing temperatures and water conditions.
Surfactants in detergents
Definition [: compounds that lower the surface tension of a liquid, the interfacial tension between two liquids, or that between a liquid and a solid. Surfactants may act as detergents, wetting agents, emulsifiers, foaming agents, and dispersants]
Surfactants actually reduce the surface tension of water by a factor of three or more. A detergent is an effective cleaning product because it contains one or more surfactants. Because of their chemical makeup, the surfactants used in detergents can be engineered to perform well under a variety of conditions. Sodium stearate, the most common component of most soap, which comprises about 50% of commercial surfactants; such surfactants are less sensitive than soap to the hardness minerals in water and most will not form a film.
Detergent surfactants were developed in response to a shortage of animal and vegetable fats and oils during World War I and World War II. In addition, a substance that was resistant to hard water was needed to make cleaning more effective. At that time, petroleum was found to be a plentiful source for the manufacture of these surfactants.
Surfactants are common to both washing-up liquids and car care products; namely Sodium laureth sulphate, or sodium lauryl ether sulphate (SLES) a foaming agent, Dodecylbenzene sulfonic acid (neutralised with Sodium Hydroxide, Triethanolamine or Isopropanolamine).
Detergent surfactants are made from a variety of petrochemicals (derived from petroleum) and/or oleo chemicals (derived from fats and oils). Petrochemicals and Oleo chemicals like the fatty acids used in soap making, both petroleum and fats and oils contain hydrocarbon chains that are repelled by water but attracted to oil and grease in soils.
These hydrocarbon chain sources are used to make the water-hating end of the surfactant molecule. Other Chemicals, such as sulphur trioxide, sulphuric acid and ethylene oxide, are used to produce the water-loving end of the surfactant molecule.
Foaming agents, emulsifiers, and dispersants are all surfactants which suspend respectively, a gas (air) an immiscible liquid, or a solid in water or some other liquid. Although there is similarity in these functions, in practice the surfactants required to perform these functions differ widely. In emulsification, as an example - the selection of surfactant or surfactant system will depend on the materials to be used and the properties desired in the end product. An emulsion can be oil droplets suspended in water, oil in water emulsion, water suspended in a continuous oil phase, or a mixed emulsion. The surfactants form what amounts to a protective coating around the suspended material, and these hydrophilic ends associate with the neighbouring water molecules.
Solubilisation - is a function closely related to emulsification. As the size of the emulsified droplet becomes smaller, a condition is reached where this droplet and the surfactant micelle are the same size. At this stage, an oil droplet can be imagined as being in solution in the hydrophobic tails of the surfactant and the term solubilisation is used. Emulsions are milky in appearance and solubilised oils, for example - are clear to the eye.
Detergency- the function of detergency or cleaning is a complex combination of all the previous functions. The surface to be cleaned and the soil to be removed must initially be wet and the soils suspended, solubilised, dissolved or separated in some way so that the soil will not just re-deposit on the surface in question
All surfactants have the following features: they make the removal of dirt easier by reducing the surface tension between the water and the paint surface, they produce foam, and this foam suspends dirt and stops it from being re-deposited.
There are surfactants that use Marangoni stress to prevent droplet formation, Since a liquid with a high surface tension pulls more strongly on the surrounding liquid than one with a low surface tension, the presence of a gradient in surface tension will naturally cause the liquid to flow away from regions of low surface tension so that water drains from the surfaces in thin sheets, rather than forming droplets, its drawback is that it leaves a thin film on the dried surface.
The benefits of using it are that it prevents "spotting" caused by droplets of water drying and leaving behind dissolved lime scale minerals, and can also improve drying performance as there is less water remaining to be dried its drawback is that it leaves a thin film on the dried surface.
Ionic and non-ionic surfactant - zwitter-ionic (amphoteric) surfactants have both cationic and anionic centres attached to the same molecule. The cationic part is based on primary, secondary, or tertiary amines or quaternary ammonium cations. The anionic part can be more variable and include sulfonates, as in CHAPS (3-[(3-Cholamidopropyl) dimethylammonio]-1-propanesulfonate). Other anionic groups are sultaines illustrated by cocamidopropyl hydroxysultaine. Betaines, e.g., cocamidopropyl Betaines Phosphates: lecithin
Zwitterionic (amphoteric) surfactants have both cationic and anionic centres attached to the same molecule.
How Detergent Surfactants Are Made Anionic Surfactants
The chemical reacts with hydrocarbons derived from petroleum or fats and oils to produce new acids similar to fatty acids. A second reaction adds an alkali to the new acids to produce one type of anionic surfactant molecule. First converting the hydrocarbon to an alcohol and then react with the fatty alcohol with ethylene oxide produce non-ionic surfactants non-ionic surfactant molecules. These non-ionic surfactants can be reacted further with sulphur containing acids to form another type of anionic surfactant.
How Soaps and Detergents work
Soap is usually a blend of several surfactants, which are two opposing polar groups, hydrophilic and a non-polar group lipophilic. The interaction of these two groups in water will reduce the surface tension of water from 72 to 35 dynes/cm soap creates foam by trapping air inside, which is about 95% air and 5% soap / water, this foam has no effect on its cleaning ability. The/surfactants use emulsification to dissolve and encapsulate oily particles and that reduces the amount of active surfactants left in the bucket. So if the surface is very oily, you will see a substantial drop in the suds and therefore a reduction in its cleaning ability.
These types of energy interact and should be in proper balance. Let's look at how they work together. Let's assume we have oily, greasy soil on clothing. Water alone will not remove this soil. Nearly all compounds fall into one of two categories: hydrophilic ('water-loving') and hydrophobic ('water-hating'). Water and anything that will mix with water are hydrophilic. Oil and anything that will mix with oil are hydrophobic. When water and oil are mixed they separate.
Hydrophilic and hydrophobic compounds just don't mix. These opposing forces loosen the soil and suspend it in the water. Warm or hot water helps dissolve grease and oil in soil.
Washing machine agitation or hand rubbing helps pull the soil free. The cleansing action of soap is determined by its polar and non-polar structures in conjunction with an application of solubility principles.
One important reason is that oil and grease present in soil repel the water molecules. Now let's add soap or detergent. The surfactant's water-hating end (lipophilic) is repelled by water but attracted to the oil in the soil. At the same time, the water-loving end (hydrophilic) is attracted to the water molecules.
Back when laundry was done with soap flakes, suds level was an indicator of cleaning performance. So, many people today think that a good rich level of suds is necessary for clean laundry. However, this is no longer true. Today's detergents are formulated to have any suds level desired without affecting cleaning performance. "They make the removal of dirt easier by adding surfactants that reduce the surface tension between the water and the paint surface.
In reality suds (a chemical foaming agent - Diethanolamides or Sodium laureth sulphate or sodium lauryl ether sulphate) do absolutely nothing to clean, they are simply a structure that a portion of the solution had taken due to being mixed with air; they still contain the same ratio of soap. They are however, a good indicator of the amount of active soap in the solution.
The amount of foaming produced has nothing to do with its cleaning efficiency (although it does provide a means of encapsulation as well as acting a cushion between the paint surfaces and cleaning tool) They are there simply because we are so engrained with the idea that soap suds do the cleaning that it is impossible to use anything else.
In almost all detergents the suds are made by a foaming agent, not by the cleaning agents in the detergent. In fact, industrial cleaners usually have no foaming agents and specialized users do not want suds. Think of a hand degreaser, or rinse less car washes (ONR) there are no suds yet it sure does the job
Car Wash Concentrates
A good quality car wash should provide a slightly alkaline pH and a balanced blend of active biodegradable ingredients, to provide lubrication to prevent scratching, surfactants and enzymes to lift and encapsulate dirt, road grime and oils. A humectant or sheeting agent attracts and retains the moisture in the air nearby via absorption, drawing the water vapour into and/or beneath the organism/object's surface. By contrast, desiccants also attract ambient moisture, but adsorb—not absorb—it, by condensing the water vapour onto the surface, as a layer of film
Washing-up Liquids (Detergent)
The use of this type of detergent has been debated for years among car detailing enthusiasts. Problems arise when people use dish washing liquid as their normal car wash soap. From a chemical standpoint using dishwashing detergents to clean a porous, sensitive clear coat paint surface is very poor choice.
Notable brands of dishwashing liquid include Procter & Gamble’s Dawn®, which is the leading brand in the United States, and Fairy Liquid, which is the bestselling brand in the United Kingdom and similar type dish washing liquids chemistry relies primarily on detergent and surfactant technology. This type of chemistry has advanced to the point that it can be engineered to specific soils (i.e. organic grease)
Detergent and soap chemistry and product formulation is a lot more complicated than this, suffice it to say; modern car wash formulations are automotive soil specific. As a means of paint surface preparation and the removal of wax / polymer sealants it’s not very effective as paint protection products are usually formulated to be detergent resistant
[Your car surface and the dirt that gets on it are a lot different from the food soils and dishes that dishwashing liquids clean effectively. We don't recommend them for cleaning your car] Proctor and Gamble
See also FAQ Proctor and Gamble website - http://www.dawn-dish.com/en_US/questionsaboutdawn.do
Water quality
Such as pH values, mineral content, harness, etc. surfactants used and other characteristics will affect how well a car wash concentrate works. As well as conditioners to maintain the shine without stripping the paint of essential oils (the way detergents do) and dispersing them in the rinsing process, warm water (not hot) will improve the cleaning abilities of wash concentrates.
The amount of foaming produced has nothing to do with its cleaning efficiency (although it does provide a means of encapsulation as well as acting a cushion between the paint surfaces and cleaning tool) when laundry was done with soap flakes; suds level was an indicator of cleaning performance. Many people still equate a good rich level of suds with cleaning; however, this is no longer true.
Today's quality car wash concentrates are formulated with anionic surfactants that have a very low suds level without affecting cleaning performance. One of the advantages of this formulation is that road dirt and grime are encapsulated in its structure (micelles), which makes for very easy and efficient rinsing.
The harsh detergents found in some car wash soaps contain sodium silicate or sodium hydroxide may etch the surface of the clear-coat leaving white residue or dulling the entire finish. Car wash concentrates that contain a high foaming (suds) agent can be corrosive, if sodium (salt) is used as an agent to create the foaming. The usual dilution is l oz. per two gallons water (using a lesser dilution will leave a film on the paint surface) Avoid products that contain harsh detergents as they will emulsify and leach out any oils or waxes that provide protection and/or flexibility
I would like to think that these articles become an asset to anyone who is new to detailing and to professional’s alike, as well as industry experts who seek to advance their knowledge.
I hope the above article was informative. By having some understanding of the ‘What’ and ‘Why’ as well as the ‘How’ along with a little science to help you understand how the chemicals we use react, you can achieve the results you desire.
