Shaving creams are applied on face for avoiding razor burns while shaving.
The major types are:- 1.Foam or Gel( use alcohol as major lubricant which causes excessive dryness to skin)
2.Tube and Tube based( glycerine is the major lubricant, so less dry on skin)
According to Burma Shave chronicler Frank Rowsome, Jr., modern shaving cream began with Burma Shave, which achieved high sales volume almost immediately after it was introduced. Prior to that time, lather was produced from a bar, and was basically another form of soap.
Manufacturing soap itself is an ancient craft—the word comes from the Old English word sape. The Holy Roman Emperor Charlemagne recognized soapmakers as craftsman. In the fourteenth and fifteenth centuries soap was made at Savona, Italy. The modern French, Spanish and German words for soap (savon, jabon, and seife, respectively) are cognates of the name of that town.
The early American settlers manufactured soap at home, by mixing and heating animal fat with lye in a pot. This "open kettle" method of soap making was popular for years.
Soap was used for shaving through the early 1800s. In 1840, a concentrated soap that foamed was sold in tablets by Vroom and Fowler, whose Walnut Oil Military Shaving Soap was probably the first soap made especially for shaving. A century later, as the United States entered World War II, animal fats of relatively uncontrolled type and quality were still being used to make soap.
In addition to raising concerns about the quality of soap, World War II contributed to the invention of the spray can. Aerosol containers were first invented during the war as a device for dealing with insects carrying malaria and other diseases. When the first aerosol shaving cream appeared in 1950, it captured almost one fifth of the market for shaving preparations within a short time. Today, aerosol preparations dominate the shaving cream market.
Raw Materials
The goal of any shaving preparation is to wet and soften the hair to be shaved, cushion the effect of the razor, and provide a residual film to soothe the skin. This film should be of the proper pH value: neither excessively alkaline nor overly acidic, it should correspond to the skin's pH level.
Many manufacturers say that the recipes for shaving cream are carefully guarded secrets. However, the secrecy revolves mostly around the quantities in which standard ingredients are used, and the choice of substitutes for the few ingredients that are variable. By law, ingredients are listed right on the container, except for perfumes.
A standard recipe contains approximately 8.2 percent stearic acid, 3.7 percent triethanolamine,. 5 percent lanolin, 2 percent glycerin, 6 percent polyoxyethylene sorbitan monostearate, and 79.6 percent water.
Stearic acid is one of the main ingredients in soap making, and triethanolamine is a surfactant, or surface-acting agent, which does the job of soap, rather much better. While one end of a surfactant molecule attracts dirt and grease, the other end attracts water. Lanolin and polyoxyethylene sorbitan monostearate are both emulsifiers which hold water to the skin, while glycerin, a solvent and an emollient, renders skin softer and more supple.
Common substitutes for the third, fourth, and fifth ingredients listed above include laureth 23 and lauryl sulfate (both sudsing and foaming agents), waxes, cocamides (which cleanse and aid foaming), and lanolin derivatives (emulsifiers). Most ingredients are powdered or flaked, although lanolin, lanolin derivatives, and cocamides are liquids.
The differences between one brand of shaving cream and another amount to adjustments in the proportions of ingredients and in the processing method (longer or shorter heating times, storage of the finished product, and so on), and choice of ingredients such as emulsifiers or perfumes. Also important is the choice of aerosol propellant. Some mixtures contain more than one propellant; most common are butane, isobutane, and propane. Though the wide range of choices for ingredients is well known, the exact combinations of ingredients represent the highest level of "magic" in modern chemistry.
The Manufacturing Process
The modern manufacture of shaving cream is a carefully controlled process. Although carried out on a large scale, its manufacture resembles a laboratory procedure involving only small quantities of ingredients. There are two main phases to the manufacturing process.
1. In the first phase, the fatty or oily portions—stearic acid, lanolin, and polyoxyethylene sorbitan monostearate—are heated in a jacketed kettle. The jacketed kettle resembles a double boiler: one container, placed inside another, is heated while steam is circulated through the outer container. Inside the interior kettle, are blades that revolve to mix the oils as they are heated.
2. After the first group of ingredients has turned smooth, the steam is released from the outer container of the kettle, and the mixture is allowed to cool.
3. The second phase of manufacture begins when the mixture has cooled. Most of the remaining ingredients—water, glycerin, and triethanolamine—are added now, and mixed
4. When the temperature of mixture is balanced, perfumes or other scents can be added. Because perfumes consist primarily of highly volatile oils, they would evaporate if added when the blend was still warm. The formulas for perfumes, which can contain more than 200 different ingredients, come closer to being trade secrets than information about shaving cream itself.
5. The mixture, still being stirred, is allowed to cool further, until it reaches room temperature. Now a thickening white mass of highly viscous liquid, it is forced through a silk or stainless steel screen to eliminate any lumps that may have formed in the mixing process, and to catch the rare impurity or foreign object such as a small wood splinter.
6. If this particular mixture is designated for tube packaging, it is now placed in a tube and fitted with a cap. After the bottom of the tube has been crimped, the product is ready for shipment and stocking on a store shelf.
7. When the desired product is an aerosol spray, the shaving cream is poured into an open can. Next a valve and a cover are fitted onto the can and forced downward to form a seal. Propellant is then forced into the can through the valve. Most shaving preparations contain between four and five percent propellant; a larger amount would dry the shaving cream as it came out of the can, rendering it unusable. A small amount of material is intentionally released (purged) to relieve excess pressure, and the can is tested in water to make sure that the valve is holding tightly. The can is now ready
Quality Control
Water quality must be checked carefully. Most manufacturers make sure the water they use is pure by exposing the water to ultraviolet light or using distilled water. Having a microbiologist on site to test the water and the final product is common in the industry.
In a typical aerosol can, the shaving cream ingredients occupy only a small portion of the can. The propellant or gas occupies 4 to 5 percent of the can; a larger amount would dry the shaving cream as it came out of the can, rendering it unusable
