Shaving Cream Manufacture
On your shaving cream if you look at the list of ingredients which by law all manufacturers must print on their packaging you will see a lot of similarities between most of the brands with the same ingredients appearing again and again. It is possible to substitute some of the key shaving cream ingredients for other ingredients with similar properties, and varying manufacturing processes will produce a different qualitys in shaving cream and with different properties. However the primary ingredients are usually the same and the basic recipe and method of manufacture can be found in many industrial chemistry text books. A standard recipe will contain; 77% water you will find water listed as aqua as the 1st ingredient in most beauty and grooming products, shaving creams being no exception.
8% Stearic acid, a saturated fatty acid that occurs in many animal, vegetable fats and oils, most commonly taken from palm oil or coconut oil.
6% Polyoxyethylene Sorbitan Monostearate, used as an emulsifiers to mix immiscible or unblendable substances. One of the easiest ingredients to substitute as there are many emulsifiers available to chemists.
5% lanolin, a kind of wax extracted from sheep’s wool, in shaving cream it acts as a lubricant and emulsifier holding water to your skin.
In other industries it can used to prevent rust and when Gillette removed from their shaving creams they were accused of doing it so their razors would rust faster and therefore need to be replaced more regularly.
3% Triethanalamine, often abbreviated as TEA, it is a surfactant or wetting agent lowering the surface tension of a liquid, one part of its molecule will be attracted to water while the other will be attracted to oils and grease. It is also used to balance the Ph value as a shaving cream must be neither overly acidic nor overly alkaline.
2% Glycerine, this will make the skin softer and more supple as it acts as a moisturiser, lubricator and humectant.
Another common ingredient you might see is laureth 23 and lauryl sulphate, in shaving creams these can be used as a substitute for lanolin, glycerine and polyoxyethylene sorbitan monostearate, they act as a surfactant lower the surface tension of liquids and will also provide lather. They are also used regularly in shower gels and face washes for the same reason.
Any variation in the ingredients proportions will affect the type and quality of the finished shaving product, also the perfume will which doesn't have to be listed on the ingredients, but is needed as without it a shaving cream will smell quite earthy and not in pleasant way. Also the emulsifiers used will affect the finished product. The method of manufacture will probably cause the greatest degree of variation, storage of the product when finished. Longer or shorter heating times, how quickly the product transferred to the tubes or tubs that it will be sold to the end user in will al have an effect.
The manufacture of shaving cream is a carefully controlled process and has two main phases. The first is when the stearic acid, lanolin, polyoxyethylene sorbitan monostearate and other fatty and oily parts of the formulation will be heated to around 80 °C to 85 °C Celsius in a jacketed kettle. A jacketed kettle is basically a double boiler with one container inside the other, in the internal container which rotates the fatty ingredients are placed, then pressurised steam is circulated around the outer container.
When the ingredients have turned smooth which should take about 40 minutes the mixture is allowed to cool to around 65 °C completing the first phase.
In the second phase the other ingredients including the water are added and the mixing continues. As most perfumes are highly volatile oils they cannot be added till the mixture has cooled to between 50 °C and 55 °C.
As the mixture cools at about 30 °C it will become highly viscous liquid as it gradually thickens. It will now be forced through a screen to sieve out any lumps, and is best left in a vat to settle and mature, after which it is now ready to be put in its final tubes or tubs and delivered to shops and stores.