Sunday 28 June 2015

What is needed to achieve effective cleaning

Basic Cleaning Requirements

As with all detailing tasks; surface preparation is the most important step to achieving e a flawless finish. The final result can only be as good as the surface it’s applied to; so surface preparation is of paramount importance. Products will properly bond to a substrate and that will ensure it works correctly, and has both durability and desired aesthetics

 Three types of energy are required;
                      Chemical energy- provided by the synthetic cleaner
                      Kinetic (abrasion) energy provided by machine or hand
                      Thermal energy -provided by warm or hot water

Test cleaner on an inconspicuous area then allowing it to dry to make sure the solution does not react with the surface, is the best way to ensure there are no surprises as to its affect, but be cognizant that it may not react in exactly the same way as a heavily soiled area or that has been subjected to UV-B radiation (faded)

Providing the cleaning product selected is suitable, apply several drops of the selected cleaning solution in an inconspicuous area and rub gently with a clean, white micro fibre towel. Do not over wet. Use small amounts of the product and blot frequently, do not rub or use too much pressure.   Do not use the product if it adversely changes your fabric's colour or texture.

Cleaning products (with the exception of glass cleaners) should be sprayed on to a folded 100% micro fibre cotton towel, do not spray any cleaning product  directly to the surface, as this may cause ‘spot or streak’ clean patches on the surface

Use a high-quality cleaner, formulated without strong solvents and one that has a pH value between 4 and 10 (neither strongly acidic nor strongly alkaline).To understand what is needed to achieve effective cleaning, it is helpful to have a basic knowledge of soap and detergent chemistry.

Water surface tension
Water is the liquid 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, those molecules are surrounded by other water molecules only on the water side. 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.

Surfactant

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."

Surfactants perform other important functions in cleaning, such as loosening, emulsifying sink dishes (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).
Soap is an anionic surfactant. Other anionic as well as non-ionic surfactants are the main ingredients in today's detergents. Now let's look closer at the chemistry of surfactants.

Soaps

Soaps are water-soluble sodium or potassium salts of fatty acids. Soaps are made from fats and oils, or their fatty acids, by treating them chemically with a strong alkali.
First let's examine the composition of fats, oils and alkalis; then we'll review the soap making process.

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 glycerine. 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.

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 Chemhydroxide (KOH), and also called caustic potash.

How Soaps are made

Saponification of fats and oils is the most widely used soap making process. This method involves heating fats and oils and reacting 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, a sodium soap is formed. Sodium soaps are "hard" soaps. When the alkali is potassium hydroxide, a 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) 10Chemend. 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 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.

Surfactants in Detergents

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. 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. Today, 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
Chemicals, such as sulphur trioxide, sulphuric acid and ethylene oxide, are used to produce the water-loving end of the surfactant molecule.
Alkalis
As in soap making, an alkali is used to make detergent surfactants. Sodium and potassium hydroxide are the most common alkalis.

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.

Non-ionic Surfactants
Non-ionic surfactant molecules are produced by first converting the hydrocarbon to an alcohol and then reacting the fatty alcohol with ethylene oxide. These non-ionic surfactants can be reacted further with sulphur-containing acids to form another type of anionic surfactant.

How Soaps and Detergents Work
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. 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 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. Washing machine agitation or hand rubbing helps pull the soil free.
Soaps & Detergents: Human Safety
As consumer needs and lifestyles change, and as new manufacturing processes become available, the soap and detergent industry responds with new products. A commitment to safety is a top priority from the time a company begins working on a new product and continues as long as the product is in the marketplace. Companies evaluate the safety of existing cleaning products by talking with consumers, reviewing scientific developments and monitoring product use data that may affect the safety assessment process.

To determine the safety of a cleaning product ingredient, industry scientists evaluate the toxicity of the ingredient. Toxicity is generally defined as any harmful effect of a chemical on a living organism, i.e., a human, an animal, a plant or a microorganism. Since all chemicals, including water (H2O), are toxic under certain conditions of exposure, scientists must consider a number of factors affecting exposure. These include the duration and frequency of exposure to the ingredient; the concentration of the ingredient at the time of exposure; and the route and manner in which the exposure occurs, e.g., eye, skin or ingestion. This information is essential whether assessing the effect on humans, animals, plants or microorganisms.

Because human safety and environmental evaluations consider different types of exposures, they are evaluated by different procedures. The principal steps in the assessment process are, however, the same. They involve: assembling existing data on toxicity and exposure; determining where new information is needed and, if necessary, carrying out appropriate studies; and determining whether predicted exposure levels are below levels that cause significant toxic effects.

This safety evaluation process enables scientists to predict the potential risk, if any, associated with the use of the ingredient or product, and determine if it is safe for consumers and the environment.
Medical science has long confirmed the important relationship between cleanliness and health. The regular use of cleaning products is fundamental to the health of our society and the well-being of its people.

Because cleaning products are part of our everyday lives, it is essential that they not present a significant risk to health. In considering the human safety of an individual ingredient or product, toxicologists (scientists who assess the safety of a chemical) are concerned with the effects from two types of exposures: intended and unintended. Intended exposures occur with use of a cleaning product according to the manufacturer's directions. Unintended exposures can result from misuse, through improper storage or by accidental contact, such as when a liquid detergent is splashed in the eye.

Hazards from these types of exposures are evaluated from information obtained through (short-term) and chronic (long-term) tests and through a review of existing data. Expected exposure routes are considered as part of this evaluation.

Human safety evaluations begin with the specific ingredients and then move on to the whole product. The effects for all ingredients are considered as the product is formulated.

Toxicologists compare the expected exposure to the expected effect during both product manufacture and use. How will workers be exposed in the plant? What is the intended use of the product? Is it to be diluted? Undiluted? Used daily in the home? Weekly in the workplace? Toxicologists also consider the expected effect of an unintended exposure. What is the potential hazard, for example, if a child drinks a product directly from the bottle?

If this human safety evaluation indicates an unacceptable risk, it may be possible to make the risk smaller by changing the manufacturing process; reformulating to reduce or eliminate an ingredient contributing to the toxic effect; or using labelling or a child-resistant closure. If the risk cannot be reduced, the product will not be marketed.

Even though manufacturers formulate cleaning products to ensure that they are safe or 06sftyhave very low risk, human health effects can still result from unintended exposure. To warn consumers about a specific hazard, household cleaning products carry cautionary labelling whenever necessary. For consumers, this is one of the most important features of the label.

Federal regulations govern how precautionary statements related to human safety are used on household cleaning product labels. The regulations require that statements follow a standard format. There is first a "signal word," followed by a short description of the potential hazard. The following chart shows the signal words - CAUTION or WARNING and DANGER - and what they mean:
POISON, which rarely appears on household cleaning products, is the strongest indication of hazard and means that accidental exposure could cause severe medical effects. The term may be found on household lye and on some car care products, such as antifreeze.

Along with the safety evaluation process and cautionary labelling, an extensive consumer education program on the proper use, storage and disposal of cleaning products supports the human safety efforts of the soap and detergent industry. In addition, the industry works closely with poison control centre’s to assure that, should an accidental exposure occur, treatment information is available to health care providers. 

Together, these activities enable consumers to use cleaning products with confidence in both their safety and performance.

Relevant Articles

  1. Basic Soap and Detergent Chemistry - http://togwt1980.blogspot.co.uk/2015/05/basic-soap-and-detergent-chemistry.html
  2.  Using pH Values to Select Detailing Products - http://togwt1980.blogspot.co.uk/2015/04/using-ph-values-to-select-car-care.html
  3. Understanding Base (Alkalinity) - http://togwt1980.blogspot.co.uk/2015/05/understanding-alkalinity.html

I would like to think that these articles become an asset to anyone who is new to detailing and to professionals 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.

I would appreciate it if you would share this article as it helps other detailers further their knowledge.
Questions and/ or constructive comments are always appreciated.


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