How Shampoos Are Made
In this cosmetic formulation series we will go through the various cosmetic & personal care formula types and describe what they are, what raw materials are in them and how they are manufactured.
Since this is a cosmetic science blog geared to introduce people to the topics of formulating, we thought it would be helpful to have a series introducing the absolute basics of formulating. And since I spent many years as a hair care formulator, the easiest to start off with is Shampoos.
What is a shampoo
Shampoos are cleaning formulations made up primarily of chemicals called surfactants that have the ability to surround oily materials on surfaces which allows them to be rinsed away by water. While there are numerous forms of shampoos the majority are slightly thickened solution formulas delivered from a plastic bottle. Often they are marketed towards different hair types or conditions.
Shampoos are typically, a solution form of cosmetic product designed to clean hair and leave it in a more manageable state. Solutions are the simplest type of cosmetic formulation, and if you’re just getting started in making cosmetics, these are the good one to start with because you mix the raw materials all together, they blend very nicely, you rarely have to worry about significant stability properties.
Types of shampoos
There are a limited number of shampoo types marketed, although they have lots of different names. In general, these shampoo include normal, extra body, moisturizing, baby, two-in-one and specialty shampoos. Almost all brands have a normal shampoo line. Now, they might call it a daily shampoo line or a regular, but it’s the base formula that will appeal to the most number of consumers.
Volumizing and Moisturizing
Most shampoo brands also have an extra body product, although sometimes they’ll be called volumizing or thickening, and these are products designed to make you look like you have more volume in your hair.
Next, are the moisturizing products. These are also known by names like conditioning, restorative, revitalizing, and they’ll address specific things like smoothing or shine. These products are designed to bring better conditioning to your hair and make the hair feel softer and behaved more manageably.
Hair breakage is a big problem for many people, so companies have designed strengthening shampoo products. These products are very much like the moisturizing products and mostly they are just a different marketing spin. But there are some tests which show that hair systems, which include shampoo and conditioner, can help to prevent hair breakage, so companies sell them as strengthening products.
Then there are the two-in-one shampoos. And two-in-one stands for shampoo plus conditioner. These are like moisturizing shampoos but with a lot more conditioning. They’re much better moisturizing shampoos than even moisturizing shampoos. Essentially, they are designed to replace the shampoo plus conditioner, so you get the most conditioning from two-in-one shampoo.
Shampoo for hair types
There are shampoos designed specifically for people with curly hair. Curly haired people could probably use the moisturizing shampoos because generally, there isn’t much difference between curly haired shampoos and moisturizing ones. But often consumers with uncommon hair like to have a specific product for them. It makes them feel more important and special.
Then we have products designed for color treated hair. These are essentially moisturizing shampoo formulas but specifically, targeted to people who color their hair.
And for people who want to enhance the color of their hair, you can get a color enhancing shampoo, which will theoretically deposit color on the hair. The way this is done is that there’s extra dye in the shampoos. And so, when people are using it, the dye will play out on the hair and change the color of hair.
Rounding out our types of shampoos include baby shampoos, which are the ultra gentle shampoos. These are designed to be tear free to be able to be used on sensitive skin of babies. They usually don’t clean as well.
Natural shampoos
There are also shampoos that are purported to be natural. These are shampoos specifically designed to avoid harsh chemicals or things that people believe shouldn’t be put on their skin. This include compounds like sulfates, which are detergents and preservatives like parabens and formaldehyde donors. Of course, there’s limited evidence that these compounds are harmful to people, however, consumers believe it so marketers have designed shampoos to address that need.
Medicated Shampoos
There are also specialty shampoos including anti-dandruff products, anti-lice and hair loss treatments, all of these are shampoos which use specific technologies to solve some highly specific problems.
Specialty shampoos
There are also a number of specialty type shampoos on the market. Powdered shampoos are all the rage which are essentially aerosol cans of pressurized powder. You spray the powder into you hair, comes out as a dry powder and then, you comb it out. The powder is designed to absorb the oils that are present in your hair and in this way you can clean your hair to some extent without ruining your style.
There’s the no-rinse shampoo, which is a foamer and you pump the foam into your hand, you run it through your hair and then, you wipe the foam up. This is useful for people who don’t have access to a lot of water.
Finally, some people are marketing what they term as a co-washing product. This is a hair conditioner that’s designed to replace shampoos. These are really fringe products, but people are using them as shampoos, so co-washing or no-poo is a no-foaming shampoo.
Shampoo raw materials
When you begin formulating a shampoo you first figure out what characteristics you want. This would include things like how thick it will be, the color, and fragrance. It also includes performance things like how well it cleans, what the foam looks and feels like and how irritating it will be. Often consumer testing is employed to help with determining these characteristics.
The basic ingredients in a shampoo formulation is as follows.
Water. The primary ingredient in all shampoos, it makes up about 70 to 80% of the entire formula. It helps dilute the detergents, makes the formula easier to spread and reduces irritation. It also keeps the formula inexpensive.
Detergents. The next most abundant ingredients in a shampoo. These surfactants are the primary cleansing ingredients and make up about 10% - 15% of the formula. They are derived from natural fatty acids or petroleum derivatives. Common primary detergents include Ammonium Lauryl Sulfate, Sodium Lauryl Sulfate and Sodium Laureth Sulfate. For natural shampoos companies have been using ingredients like Decyl Glucoside and Lauryl Glucoside.
Foam Boosters. Other types of surfactants are added to shampoos to improve the foaming characteristics of the formulation. Consumers like a nice creamy foam even though it doesn’t actually affect how well the product works. Foam boosting compounds, usually betaines or alkanolamides, help increase the amount of foam and the size of the bubbles. Like primary detergents, these ingredients are also derived from fatty acids and have both water soluble and oil soluble characteristics. Typical materials include Lauramide DEA or Cocamidopropyl Betaine. They make up about 5-10% of the entire formula.
Cosmetic Thickeners. To some extent the secondary detergents make shampoo formulations thicker. Simply adding salt can also increase shampoo thickness. However, other materials are also used to increase the viscosity such as Methylcellulose which is a cellulosic polymer or Carbomer which is a synthetic polymer.
Conditioning agents. Some materials are added to shampoos to offset the harsh effect of surfactants. Typical conditioning agents or moisturizing ingredients include polymers, silicones, and quaternary agents. These ingredients are left on the hair surface after rinsing and modify characteristics such as feel, softness, combability, and static charge. Shampoos that specifically feature conditioning as a benefit are called 2-in-1 shampoos because they clean and condition hair in the same step. Examples of conditioning agents include Polyquaternium-10, Guar Hydroxypropyltrimonium Chloride which are polymers, Dimethicone and cyclomethicone which are silicones, and Quaternium 80, a quaternary agent.
Preservatives. Any formula that contains water has the potential to be contaminated by bacteria and other microbes. For this reason cosmetic preservatives are added to prevent such growth. Two of the most common preservatives used in shampoos are DMDM Hydantoin and Methylparaben. For natural shampoos ingredients like Sodium Benzoate, Benzyl Alcohol and Phenoxyethanol are used.
Other ingredients. A variety of other compounds are included in shampoos if desired. Dyes for changing color, fragrances for changing the odor, pH adjustment ingredients, chelating agents, opacifying ingredients, and more. Frequently, story ingredients are included so marketers will have something to talk about. This includes things like vitamins, proteins, and herbal extracts which are not normally expected to have any impact on the final product performance. Medicated shampoos like anti-dandruff shampoos will include a drug active ingredient like zinc pyrithione.
Shampoo Manufacturing Process
The manufacturing process can be broken down into two steps. First a large batch of shampoo is made and then the batch is filled into the packaging.
Compounding. The process of any large scale cosmetic production is called compounding. All the ingredients are mixed together in large, stainless steel tanks (3000 gallons or more) by workers known as compounders. The raw materials, which are typically provided in drums as large as 55 gallons or in 50 lb bags, are poured into the batch tank and thoroughly mixed. The order and temperatures are determined by the formulating chemist. Some ingredients like water or the primary detergents which make up the bulk of the product are pumped and metered directly into the batch tank. A computer interface is often used to control mixing speed and temperature. Depending on the size and type of shampoo, making a 3000 gallon batch can take any where from 1 to 4 hours or longer.
Quality Control check. After a batch is completed, it is sent to the quality control department for approval. Here they test it for things like proper pH, viscosity, color, odor and other specified characteristics. Once approved by the QC department, it is pumped out of the main batch tank into a holding tank where it can be stored until the filling lines are ready. From the holding tank, the shampoo gets pumped into a filler which is positioned on the filling line.
Filling. The filling line is just a long conveyor belt. At the start of the filling line, empty bottles are put into a hopper. The bottles are physically manipulated by a machine until they are upright and correctly oriented. They move along the conveyor belt to the filling carousel which holds the shampoo.
The filling carousel is made up of a series of piston filling heads that are calibrated to deliver exactly the correct amount of shampoo into the bottles. As the bottles move through this section of the filling line, they are automatically filled with shampoo.
From here the bottles move to capping machine where caps are put on. This can also be done by workers depending on the speed of the filling line. Next, labels are applied, then the bottles are moved to a sorting machine that puts them into boxes. The whole process can take minutes or hours. It just depends on how advanced the filling process is.
This video shows an example of a shampoo being filled.
That’s it!
Do you have any questions about shampoo formulas? Leave a comment in our cosmetic science forum.
