Viscosity adjusters, shampoos

A particular viscosity level is then attained through addition of salt, usually sodium chloride (Section II.C.2). Salt increases viscosity up to a point, after which addition of more salt reduces viscosity. Generally, shampoo viscosity is adjusted on the rising portion of the salt curve. 

A simple shampoo consists of a mixture of water, sodium lauryl sulfate, and an amide to make it foam. I heat the mixture and then I have to adjust the acidity. Most shampoos are neutral. If it s more basic than that, I adjust it with a citric acid solution. Then I cool it and check the viscosity, or how it flows. I don t want it to be either water-thin or molasses-thick, so I ll adjust the viscosity by using a 20 percent sodium chloride solution. Perfume and color are added to make it smell and look good. 

U.S. 5478490 (1995) Russo et al. (Lonza) Polyglyceryl esters Meet baby shampoo criteria without the need of using ethylene oxide derivatives viscosity and clarity can be adjusted by tailoring the polyglyceryl ester... 

Shampoos normally contain a blend of cleansing agents (usually two anionic surfactants or an amphoteric and an anionic), foam booster (also a surfactant, most often an alkanola-mide), conditioner, viscosity improver (inorganic salts or cellulose derivatives), opacifier, dye, perfume, biostats (often esters of p-hydroxybenzoic acid), and perhaps chelates (EDTA or citric acid). Propylene glycol or glycerin may be present to adjust solubility and viscosity. Depending on current fashion, other compounds will be present, such as vitamins and food or herb extracts (26,27). 

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